# Critical information on cam timing!!!!!!!!



## baldyhunter (Jan 22, 2006)

..............it's not at all what you think it is LOL.



Sorry for the sensationalism but I wanted more than two hits. Here's the deal. Too many people on this sight have either just given into the misconception in terminology and mislabel synchronization as cam timing, or they really have no idea what cam timing refers to. I've seen a lot of threads lately where people call synchronization "timing". I think since they are two very different concepts they should be labeled differently in order to avoid confusion. They are also both two critical aspects of the bow tuning process so need to be labeled differently as any good tuning thread should handle these two concepts seperately. This is my last try, for the record, to set AT straight. If I'm unsuccessful this time I will personally call timing (timing) and synchronization (timing) as well and thus confuse many people LOL. 

First thing first....Cam timing has absolutely nothing to do with the draw stops hitting together at the same time...nothing! Cam timing is also just as critical to single cam bows as it is to dual cam bows. What timing refers to is when things happen during the draw cycle. For example, once you start pulling the string, when the bow hits peek weight, when the bow starts into the valley, and when you hit the base of the valley or stops. Timing is controlled by cam orientation while the bow is at brace. For example, if the cam timing is advanced it will hit peak weight later in the draw cycle and hit the stops, or base of the valley, sooner. Conversely, if the cams are r e t a r d e d peek weight will come sooner and the valley will come later. There really are a lot of important things to consider when setting cam timing. While it is being adjusted you are also adjusting peak weight, draw length, duration or length of the plateau, lettoff, and how much energy a cam stores during the draw cycle. When manufactures have referances on their cams they are giving you a recomended timing position on the cam. This referance is usually the best position for a 29" draw. Another thing to consider while setting the timing on a bow is that two identical bows can have two drastically different draw force curves....all related to timing. Again, it is a fundamental and critical aspect of tuning that has absolutely nothing to do with draw stops hitting together or 2 cams working together...nothing 

Synchronization on the other hand is hardly ever mislabeled...but hardly ever used. Synchronization IS getting the draw stops on a dual cam hitting together at the same time or otherwise getting two cam systems working both cams together. It is a critical aspect of tuning any two cam system. I think this is something we all understand so I won't go into detail. 

One last effort to convince everyone labeling things correctly is important. I had a customer call a few weeks ago and describe to me how his shop tuned his bow. He called a week before his shop visit and asked me about the timing dots on his Destroyer and how the cables both lied on the outside of the referance dots (which is not necessarily bad in some of the short draw settings). I told him his timing was off and the shop needed to put 5 or 6 twists in the cables (his ATA was long as well) to bring the cables back between the dots. He took the bow to a shop and told them the timing needed adjusted. They proceeded to put the bow on a draw board and checked to make sure the draw stops hit at the same time at full draw. They gave him the bow back and said the timing was perfect LOL. He then handed the bow back and told them that the cables were outside the referance marks on the cam and that the timing needed adjusting. Their response, "We already timed it and that's the only way you can time a bow". Some people should not be working on bows! I've seen this many, many times. Timing is the one thing that is really misunderstood and miscommunicated. More people (especially dealers) should understand this more clearly and that understanding will come harder if we keep meshing these two ideas under one name.

End of rant.
Ken


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## DannyZack (Oct 19, 2010)

Good rant! Lol very informative


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## bow_hunter44 (Apr 20, 2007)

Nice rant!


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## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> ..............it's not at all what you think it is LOL.
> 
> 
> 
> ...


Hello Ken:

This is why I avoid....

a) medical names in Latin for muscles
b) medical names for bones
c) engineering names...physics terms...advanced mathematics
d) "cam timing"
e) "cam synch"..."cam synchronization"


I much prefer....draw stops hitting at the same time. Draw stop hitting first on top, with a credit card thickness of a gap on bottom.

I much prefer...cam starting rotation position,

No confusion this way.


I agree with everything you have said.


I hear you about the single cams. I see soooooo many times
where folks say a single cam is as SIMPLE as it gets. Since ONLY ONE cam....."it can never get out of time."

Baloney.

The cam starting rotation position is ABSOLUTELY critical for a single cam.

I just bought a single cam (Apex 7).

Getting the Apex 7 to shoot a level bareshaft
AND
FIXING the draw length (29-inch Apex 7 cam) to hit a real world 29-inches....(had to whack off 1/4-inch on the dL)
was a pain in the patoot-ey.


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## jaredc (Mar 23, 2008)

Great post! Wish more rants were that informative!


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## tichound (Mar 3, 2008)

What would you do on the PSE L6 cam system?
One draw stop on the bottom cam.


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## Fortyneck (Oct 8, 2010)

But as far as cam timing, a cam that is DL specific will be in optimal time when the cam starting rotation position "lines up" with manufacture references.

Correct?


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## nuts&bolts (Mar 25, 2005)

Fortyneck said:


> But as far as cam timing, a cam that is DL specific will be in optimal time when the cam starting rotation position "lines up" with manufacture references.
> 
> Correct?


Easier if you give you the details.

What bow?

If we are talking a newer Mathews,
then there is a cam timing reference hole.

Mathews Reezen.


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## nuts&bolts (Mar 25, 2005)

tichound said:


> What would you do on the PSE L6 cam system?
> One draw stop on the bottom cam.


The L6 cam system is a hybrid cam system.

Buss cable.
Control cable.
Bowstring.

So,
you have a HARD stop on the bottom cam.

So,
you have a DL module, with a long straight section on the top cam / idler wheel.











So,

a) assuming your bow is hitting factory spec for ATA, when the limb bolts are at maximum

b) assuming your bow is hitting factory spec for BH, with the limb bolts at maximum....

you want the top cam / idler wheel DL module (flat section) to contact the cable

at the same time the draw stop on the bottom, also contacts the cable.

This is a GOOD starting point.

Then,
you go to the practice range
and you creep tune
at 20 yards,
and fine tune the cam starting rotation positions...
with adjustments to the twists to the cables.

You can tweak the buss cable.
You can tweak the control cable.

Half a twist is usually all you need to do,
to hit the sweet spot, for creep tuning.

Maybe a full twist...at most.


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## baldyhunter (Jan 22, 2006)

nuts&bolts said:


> Hello Ken:
> 
> This is why I avoid....
> 
> ...


I agree 100% but what a pain in the butt LOL "cam starting rotation position" I honestly never want to type that again instead of just saying "timing". I must have less time than you or maybe I'm just more lazy but wouldn't it be nice if people understood this better and we were all on the same page here ...probably just a pipe dream. Apex 7 is a very nice bow. Many of those Mathews bows shoot better with the timing advanced....but then you have to pull ATA in to compensate for the loss in peak weight...which often leads to a new string set LOL. Your right a pain.


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## swbuckmaster (Dec 20, 2005)

Nuts and bolts
I am interested in how you fixed or shortened your draw and was able to get bare shaft level flight.
I also have the apex7 and recently shortened the draw a 1/4 inch. I gave up on the level flight part and settled on the best hold. Meaning I twisted the string up till it felt perfect. I then took a half twist out of cable and pulled it back to check my float. I then went the other way and did the same thing. I did this until I found the best cam position for smallest sight pattern. 
I then just set the rest to 13/16 and then moved the rest down until I thought It wasn't affecting the flight.

It will shoot multiple arrows in the same hole out of a hooter. So im guessing if it holds as good as it can then i should be able to shoot it like a machine. 

I am shooting better and better but it goes against what I've always preached. Perfect bullet holes, bare shaft hitting with fletched shafts, ect. But man it holds and shoots well!

Sent from my DROIDX using Tapatalk


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## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> I agree 100% but what a pain in the butt LOL "cam starting rotation position" I honestly never want to type that again instead of just saying "timing". I must have less time than you or maybe I'm just more lazy but wouldn't it be nice if people understood this better and we were all on the same page here ...probably just a pipe dream. Apex 7 is a very nice bow. Many of those Mathews bows shoot better with the timing advanced....but then you have to pull ATA in to compensate for the loss in peak weight...which often leads to a new string set LOL. Your right a pain.


Hello Ken:

My life mission is to explain in such a way,
that folks understand,
and can have a better time shooting their bow....

even if the cost is a typing extra words.


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## nuts&bolts (Mar 25, 2005)

swbuckmaster said:


> Nuts and bolts
> I am interested in how you fixed or shortened your draw and was able to get bare shaft level flight.
> I also have the apex7 and recently shortened the draw a 1/4 inch. I gave up on the level flight part and settled on the best hold. Meaning I twisted the string up till it felt perfect. I then took a half twist out of cable and pulled it back to check my float. I then went the other way and did the same thing. I did this until I found the best cam position for smallest sight pattern.
> I then just set the rest to 13/16 and then moved the rest down until I thought It wasn't affecting the flight.
> ...


I purchased my FIRST used Mathews bow...which is also, my FIRST solo cam bow (personal use).
Mint condition Apex 7, from an estate sale (owner passed away).

Factory strings. 29-inch DL fixed cam.

BUT.....
the real world draw length measured out at 29.25-inches. ATA was at factory spec of 38-inches. BH was factory spec at 7.0-inches.

Aaaargh!

Soooo,
experimented with shortening the bowstring length. Cam timing is now WAY out of whaaack.
Bareshaft flight is HORRIBLE.

So,
gotta get the cam starting rotation position back to factory spec.

ONLY way to maintain the cam starting rotation position
and FIX the draw length (reduce 1/4-inch) is to knock down the brace height by 1/4-inch
AND
maintain the cable to bowstring wrapping ratio.

1) Build a custom buss cable (longer than spec)....bonus, is I added a 10-inch floating yoke system.
Had to work out the mathematics...

came up with NEW STRING LENGTH =....... 95-11/16ths......7/16ths LONGER than factory spec...(factory spec string length will NOT deliver an accurate draw length).
came up with NEW BUSS CABLE LENGTH = 40-11/16ths......3/16ths LONGER than factory spec...(factory spec buss cable length will NOT deliver an accurate draw length).

So,
the END RESULT = DEAD ON perfect 29-inch draw length.

BRACE height is now 6.75-inches.

CAM starting rotation position is DEAD PERFECT

Bareshafts now actually fly DEAD LEVEL.

So,
my conclusion is that the good folks at the Mathews Marketing Department (my wild guess...I don't actually know)
over-ruled the Engineering department at Mathews
and said that......a 6-3/4 inch BRACE HEIGHT bow will NOT sell....fix it and make the brace height 7.0-inches...and round out the ATA to some even number.


So,
you end up with a nice even 38.0-inch ATA
you end up with a nice even 7.0-inch Brace Height
and you stamp the cam as 29.0-inches (Fixed Length Cam)...

and you deliver a real world draw length of 29.25-inches.


My New ATA = 38 and 13/32nds....instead of 38.0-inches
BH = 6.75 inches instead of 7.0
Draw Length = perfect 29.0-inches.


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## nuts&bolts (Mar 25, 2005)

swbuckmaster said:


> Nuts and bolts
> I am interested in how you fixed or shortened your draw and was able to get bare shaft level flight.
> I also have the apex7 and recently shortened the draw a 1/4 inch. I gave up on the level flight part and settled on the best hold. Meaning I twisted the string up till it felt perfect. I then took a half twist out of cable and pulled it back to check my float. I then went the other way and did the same thing. I did this until I found the best cam position for smallest sight pattern.
> I then just set the rest to 13/16 and then moved the rest down until I thought It wasn't affecting the flight.
> ...


IN the end,
you tweak a bow until it shoots well for YOU.


I like to tune bows,
and I like to build strings,
and I like to solve puzzles.

I wanted to see what it would take
to get a Mathews Fixed Cam....to actually deliver real world specs...rather than kinda sorts specs,
for DL.

Now that I have the Apex 7 tuned to real world factory specs (draw length)...

I will see what it takes to get the most performance,
out of the Apex 7 system.


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## baldyhunter (Jan 22, 2006)

nuts&bolts said:


> Hello Ken:
> 
> My life mission is to explain in such a way,
> that folks understand,
> ...


That is a very noble undertaking N&B! Maybe if you put "timing" in parenthaseize after you write "cam starting rotation possition" it would help people better understand the terminology that will in turn help them understand tuning their bows.

Thanks for all you do here
Ken


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## BowhunterCliffy (Feb 19, 2007)

how do u know where timing marks are on different bow cams? this info in the respective manuals?


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## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> That is a very noble undertaking N&B! Maybe if you put "timing" in parenthaseize after you write "cam starting rotation possition" it would help people better understand the terminology that will in turn help them understand tuning their bows.
> 
> Thanks for all you do here
> Ken


Good idea.

Will do.


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## baldyhunter (Jan 22, 2006)

nuts&bolts said:


> I purchased my FIRST used Mathews bow...which is also, my FIRST solo cam bow (personal use).
> Mint condition Apex 7, from an estate sale (owner passed away).
> 
> Factory strings. 29-inch DL fixed cam.
> ...


The down side of this would have to be a loss in peak weight....just so people better understand the compromises involved in this type of thing.


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## nuts&bolts (Mar 25, 2005)

BowhunterCliffy said:


> how do u know where timing marks are on different bow cams? this info in the respective manuals?


Most times.

Hoyt has reference marks for the Spiral cam system.

Bowtech has reference marks / dots for the Bowtech binary cam system.

NOT all cams have reference marks along the outside edge of the cam.


The older Mathews cams have DIMPLES (total of two) to form an imaginary line
that should be parallel to the bowstring, with the bow at rest.











Other Mathews cams have tiny holes where the dimples are located.


Other NEWER Mathews cams have a nice, single, large timing hole.











Then,
you have the hybrid cam systems....sometimes with a hard draw stop....sometimes, just with two flat sections of the DL module.


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## dwagoner (Sep 27, 2007)

i like it Baldy, i LIKE IT !!!! get it all out of the system and make it correct!! It took me a while when i got my first 2 hoyts to work with the cam system and getting it all tuned, now it dont have all the tools to get it super tuned but it took some tinkering to get it figured out and get them dialed in. im glad i learned hybrids first as i think after you do some dual cam systems and understand them it makes it easier to to the singles. I just wish all bows came with marks to help people do the work, not just for dealers but all people, ie like the new cams on the mathews Z bows, the hole is simple and reliable!! But none the less great post and hope people read it


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## Fortyneck (Oct 8, 2010)

Fortyneck said:


> But as far as cam timing, a cam that is DL specific will be in optimal time when the cam starting rotation position "lines up" with manufacture references.
> 
> Correct?





nuts&bolts said:


> Easier if you give you the details.
> 
> What bow?


My question/point was that with DL specific cams the timing reference mark is where it should be for your DL, and the OP statement "This referance is usually the best position for a 29" draw" refers to cams with DL adjustability.



nuts&bolts said:


> ...My life mission is to explain in such a way,
> that folks understand,
> and can have a better time shooting their bow....
> 
> even if the cost is a typing extra words.


Thats why your the man, typing the extra words makes the information more accessible, leaves less open to subjective interpretation.(guess work)

...and the pictures... one might say they are worth... well


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## vftcandy (Nov 6, 2009)

What is a cam?:wink: Preach it Baldy!


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## baldyhunter (Jan 22, 2006)

Fortyneck said:


> But as far as cam timing, a cam that is DL specific will be in optimal time when the cam starting rotation position "lines up" with manufacture references.
> 
> Correct?


Yes,
if they are draw specific then they are marked at the factory recommended position for that DL.


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## baldyhunter (Jan 22, 2006)

vftcandy said:


> What is a cam?:wink: Preach it Baldy!


Funny LOL
You shoot nice strings BTW!


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## fletched (May 10, 2006)

The word timing has been used for years instead of synchronization. It confuses some people if you use synchronization instead of timing. Even though you are right, most will still use the wrong term.


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## ex-wolverine (Dec 31, 2004)

Ken

Dont all you tuners just throw strings on and paper tune; what are you worrying about all that sync Vs timing stuff, peak weight and draw force curve and the list goes on for?:wink: Im going to tell Dale on you

Great post by the way!!!


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## fletched (May 10, 2006)

vftcandy said:


> What is a cam?:wink: Preach it Baldy!


It's one of those thangs you use to take pictures with.


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## vftcandy (Nov 6, 2009)

fletched said:


> It's one of those thangs you use to take pictures with.


Ah, Got it...this is why I love AT..so much great info. Can ya tell me how to turn one on, I put batteries in mine but nothing happens.


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## dwagoner (Sep 27, 2007)

ex-wolverine said:


> Im going to tell Dale on you


GOD please dont!!!! couldnt take that guy getting on here and starting in........


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## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> The down side of this would have to be a loss in peak weight....just so people better understand the compromises involved in this type of thing.


Yes, a compromise.

IN order to get my Apex 7 to hit a real world 29-inch draw length
(it was drawing 1/4-inch on the LONG side)...
I had to reduce the BH by 1/4-inch...

which means,
I increased the ATA and dropped the draw weight some.

Everything has a price.


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## Washi (Jan 23, 2005)

I finally figured out my local shop synchs the cams but doesn't time them. They also told me my bow was drawing 29" but I found out it was actually drawing 29 3/4". This was before I knew much of anything about bows.


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## R0CKETMAN (Sep 10, 2008)

baldyhunter said:


> I agree 100% but what a pain in the butt LOL "cam starting rotation position" I honestly never want to type that again instead of just saying "timing".





nuts&bolts said:


> Hello Ken:
> 
> My life mission is to explain in such a way,
> that folks understand,
> ...





baldyhunter said:


> That is a very noble undertaking N&B! Maybe if you put "timing" in parenthaseize after you write "cam starting rotation possition" it would help people better understand the terminology that will in turn help them understand tuning their bows.
> 
> Thanks for all you do here
> Ken



The problem isn't with the concept, but rather the terminology. 
Synchronize: to happen at the same time. 

So, (nuts ans bolts loves it when I use the word SO) the word time is interjected from the start. This explains why Baldy's customer went into a shop and the two "tuning" concepts were combined. 

I'm of the opinion that the word "timing" should be banned.


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## bambikiller (Feb 27, 2004)

subscribed so i can read it after wrk


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## spmnlvr (Apr 28, 2009)

Awesome thread thanks guys.....Baldy I am one of the people that piss you off constantly by misusing "timing" and "sync". My apoligies.

Tell me if I'm wrong. When I sync my bows (Alien X and GT500) I look at where the cables roll into the valley and sit in the valley and make measurments from there. I have never used "timing" dots.

In other words could you explain how to find proper sync? or is it always different depending on what the owner is looking for? Am I totally missing something?


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## Olink (Jan 10, 2003)

Great thread.
Many a time I have asked about a timing reference of a particular cam, only to have all the replies come back telling me how to synchronize the bow.
Personally, I am dumbfounded by the level of ignorance in the archery community pertaining to sychronization and timing. Understanding the difference between the two is not a difficult concept.


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## MELLY-MEL (Dec 22, 2008)

In to read later


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## Bearlee (Dec 24, 2009)

learning more everyday, thanks folks!


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## ontarget7 (Dec 30, 2009)

:thumbs_up


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## yellowdogg (Oct 16, 2010)

Lovin this info, this is why I keep coming back here (AT).


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## wvbowhunter09 (Mar 14, 2009)

What if your bow is synchronized but the stop are not hitting at the same time. Say it is a bow that has fixed draw stops. Wouldn't you have to mess up the synchronization to fixed the stops?


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## rutjunky (May 22, 2011)

I just got so confused i puked.


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## ontarget7 (Dec 30, 2009)

You must of looked right over this one



wvbowhunter09 said:


> What if your bow is synchronized but the stop are not hitting at the same time. Say it is a bow that has fixed draw stops. Wouldn't you have to mess up the synchronization to fixed the stops?





baldyhunter said:


> ..............it's not at all what you think it is LOL.
> 
> 
> 
> ...


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## baldyhunter (Jan 22, 2006)

wvbowhunter09 said:


> What if your bow is synchronized but the stop are not hitting at the same time. Say it is a bow that has fixed draw stops. Wouldn't you have to mess up the synchronization to fixed the stops?


You will have to change (slightly) the timing of one cam to get it synchronized...But you won't be messing it up...you'll be making it better.


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## baldyhunter (Jan 22, 2006)

r0cketman said:


> the problem isn't with the concept, but rather the terminology.
> Synchronize: To happen at the same time.
> 
> So, (nuts ans bolts loves it when i use the word so) the word time is interjected from the start. This explains why baldy's customer went into a shop and the two "tuning" concepts were combined.
> ...


lol


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## baldyhunter (Jan 22, 2006)

Washi said:


> I finally figured out my local shop synchs the cams but doesn't time them. They also told me my bow was drawing 29" but I found out it was actually drawing 29 3/4". This was before I knew much of anything about bows.


Sounds like you got them figured out pretty good! There are a lot of shops just like yours.


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## baldyhunter (Jan 22, 2006)

fletched said:


> The word timing has been used for years instead of synchronization. It confuses some people if you use synchronization instead of timing. Even though you are right, most will still use the wrong term.


Your soooo right Fletched...but it has been a lot of fun so far trying.


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## Fortyneck (Oct 8, 2010)

wvbowhunter09 said:


> What if your bow is synchronized but the stop are not hitting at the same time...


Your bow(cams) are not synchronized if the stops don't hit at the same time.



rutjunky said:


> I just got so confused i puked.


Lol!


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## fletched (May 10, 2006)

Now on to the next subject..............cam advancing and cam reterding.


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## baldyhunter (Jan 22, 2006)

spmnlvr said:


> Awesome thread thanks guys.....Baldy I am one of the people that piss you off constantly by misusing "timing" and "sync". My apoligies.
> 
> Tell me if I'm wrong. When I sync my bows (Alien X and GT500) I look at where the cables roll into the valley and sit in the valley and make measurments from there. I have never used "timing" dots.
> 
> ...


I'll address this one later....long response planned...off to the shop.


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## baldyhunter (Jan 22, 2006)

fletched said:


> Now on to the next subject..............cam advancing and cam reterding.


I already "terded" my cams up yesterday...more fun than I expected.


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## chevman (Nov 3, 2006)

I know this is asking a lot but you can always say NO!!. I have read Javi's version of tuning a hoyt cam1/2+. Could you do a step by step for us? I have two of them that i just got and want to check them out.


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## NMP (Aug 6, 2003)

nuts&bolts said:


> The L6 cam system is a hybrid cam system.
> 
> Buss cable.
> Control cable.
> ...


There is no flat section on the L6 or TH cams.


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## straight2it (Nov 30, 2010)

nuts&bolts said:


> I purchased my FIRST used Mathews bow...which is also, my FIRST solo cam bow (personal use).
> Mint condition Apex 7, from an estate sale (owner passed away).
> 
> Factory strings. 29-inch DL fixed cam.
> ...


Amazing journey, when you make a bow, I want one!


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## straight2it (Nov 30, 2010)

baldyhunter said:


> ..............it's not at all what you think it is LOL.
> 
> 
> 
> ...


So timing has to do with peak weight during draw and the "time " when the draw enters into its valley? Is that correct?


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## nuts&bolts (Mar 25, 2005)

NMP said:


> There is no flat section on the L6 or TH cams.


That makes things harder.

The two pictures above are from the PSE tech manual...albeit a generic tech manual.

I tried to look for timing info on the PSE website for the L6 cam,
but could not find one.

If there is no "flat section" on the draw length module on the top cam
and you are relying completely on the draw stop on the bottom cam...

then,
there must be some kind of reference mark
on the top cam,
to tell you that the top cam is in the correct rotation position,
when the bow is at full draw.

If you can post up a picture...a close up picture of the L6 cam up on top (both sides of the cam),
then,
I can probably spot it.


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## nimrod1034 (Oct 31, 2011)

Couple things

1. This should be a sticky. 

2. If Nuts & Bolts wrote a book I would buy it. 

3. How did you learn all of this? By reading books, tinkering, or a mixture. Also can someone suggest a some kind of like reference guide or book I could get that has all this kind of info like different cam systems, building strings, tuning, etc..


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## walks with a gi (Oct 1, 2002)

Cam synchronization should be set at brace. If the cams are indexed to the factory dots or marks, and those marks are put on the cams in identical positions on the cams and then referenced by cables that have different angles leading to the reference marks, due to the cables not crossing in the exact center of the bow, the cams are not synchronized to stop at the same instant at the end of the shot cycle. Why wouldn't you want both of your cams to stop at the same instant, with the same power stroke applied to the arrow? 

IF, the cams are marked correctly and take into consideration the normal (above center cable crossing) then it's best to sync the cams to the reference marks. If this situation also has dual draw stops that are designed to contact the cables at the same time with correctly designed reference marks,, it's a very well designed cam system that takes everything into consideration.


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## nuts&bolts (Mar 25, 2005)

chevman said:


> I know this is asking a lot but you can always say NO!!. I have read Javi's version of tuning a hoyt cam1/2+. Could you do a step by step for us? I have two of them that i just got and want to check them out.


The Hoyt hybrid cam system...all versions of the hybrid cam system...
has these basic parts.

1) buss cable (also called a yoke cable)...which has 3 end loops.
2) control cable....which has only 2 end loops
3) top metal thingy and bottom metal thingy

The buss cable controls the ATA.
The buss cable provides the squeezing together of the limb tips (controls draw weight).

The control cable just links the two metal thingies together. One metal thingy rotates,
then the other metal thingy must follow and rotate, as well.

The control cable and the bowstring are cousins.

Tweak the control cable (looser or tighter)
and the two metal thingies rotate.

Tweak the bowstring (looser or tighter)
and the two metal thinges rotate...just not as much.

So,
tweak the control cable, and you get say........THAT much rotation on the two metal thingies.

So,
tweak the bowstring, and you get say....THIS much rotation on the two metal thingies....less rotation, but at least some.


Sooo,
JAVI's method...is as follows:


1) max out your limb bolts

2) find your tune chart for your year and model of bow. If the tune chart says 29-inches of DL when the module is set to the "D" position....then,
set YOUR module to the "D" position...for tuning purposes.

3) So, if you have the module set to whatever the TUNE chart says, and the DL setting is SUPPOSED to be 29-inches....

4) pop your bow into the draw board, and look for a tape measure measurement of 27.25-inches...1.75-inches LESS than the Tune Chart draw length.

5) pop your bow into the portable bow press and relax the bowstring...untwist and make it loose..JAVI suggests 10 twists LESS than normal

6) tweak the buss cable so that your ATA is 1/4-inch LONGER than factory spec...make sure that the bowstring is still loose, cuz you want the buss and control cable to the PRIMARY thing holding your bow together....pressure is tight 
in the buss and control cable.....pressure is loose in the bowstring.

7) so, now your ATA is 1/4-inch longer than FACTORY SPEC (see Hoyt tune chart)

8) now, gotta tweak the control cable (remember...the two end loop cable) to get the cams in the correct starting rotation position at THIS point...so that the draw stops (the straight flat sections on the DL modules to hit the cables at the same moment). So, in the JAVI thread...he says to look at the reference marks on the sidewall (near the edges) of the cam. You want to be on the same reference mark on both cams.

If you don't have reference marks, you can still unpress your bow (bowstring will be too long..so the cams will look weird) and you can use a draw board,
to confirm that the bow hits full draw 
(draw stops hit the cables at the same time).

If ONE draw stop (straight flat section of the module) hits the cable first,
and the other draw stop has a gap between the flat section and the cable..

then,
tweak the control cable....(try shorter...try longer...ADD half twists...REMOVE half twists)
until the draw stops BOTH hit the cables at the same time.

9) Now,
go back to the portable bow press
and twist up the bowstring SHORTER and SHORTER until
you get a 27.25-inch tape measure reading
on the draw board,
IF you have the 29-inch DL module in the tune chart.

When you get the 27.25-inch tape measure reading on the draw board,
then,
your 29-inch DL module is providing 29-inches of draw length.

Confirm that the draw stops are still hitting the cables together.

If you like,
tweak the control cable a half twist (one direction or the other)
so that the TOP draw stop contacts the cable FIRST
and
you have a tiny teeny itsy bitsy gap
between the bottom draw stop and the bottom cable.


This is still just a STARTING point.

You still need to go to the practice range
and do the creep tuning at 20 yards.

Creep tuning
will have you CUSTOM adjust the control cable
shorter or longer,
by a half twist or at most a single full twist,
to find the sweet spot for cam starting rotation position,
for the way YOU apply pressure to the grip of your bow, with your bow hand.

Normal shots
and HARDER into the wall shots
should ALL hit the target at the same elevation above the ground.

If normal versus HARDER into the wall arrows
are hitting the target at DIFFERENT elevations (normal hitting lower...HARDER hitting higher...or the other way),
gotta tweak the control cable by a half twist or a full twist at most.

Tiny adjustment goes a long way.


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## NMP (Aug 6, 2003)

nuts&bolts said:


> That makes things harder.
> 
> The two pictures above are from the PSE tech manual...albeit a generic tech manual.
> 
> ...


There is no module on the top cam at all. There is a referrence mark for the start position for the top and bottom. The cable track on the top is round. I think this was done to eliminate the need to synchronize the cams. The top cam acts more as an idler wheel than a cam but the string track is still offset to the axle to give the effect of being an eccentric wheel. You can see what I mean when looking at the Dominator TH cams here. http://tune.pse-archery.com/BowDetail.aspx?Year=2011&Model=1132TH


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## field14 (May 21, 2002)

Do we dare talk about INTENTIONALLY "clocking" or "un-clocking" the cams to get better grouping, forgiveness, and performance out of your system?

OMG...then, in the "day" we INTENTIONALLY placed more 'pre-bend' into the limbs to improve performance regardles of the fact that limb-life was reduced by quite a bit.....We pretty much knew the limits in the amout of pre-bend a limb type would take (by brand of bow), and stayed on the edge of that limit...but would work with it until the bow settled down and we were getting the best performance, least vibration, tightest groups (sweet spot), and most forgiveness we could find for that setup and arrow combination.
Wasn't done in a day and often times we didn't bother with PAPER TEAR...but went for the groups at 65 yards +, because if the bow grouped tight at 65 yards, 20 yards was a chip shot. We knew years ago that a 20 yard "tune" didn't cut it...for anything but 20 yards (if that), but a 65 yard tune or even a 40 yard tune was even tighter at 20 yards!
Take all the arrow sizes you have, INCLUDING your various FAT SHAFTS, and tune for the tightest group you can get with each of them at 40 or even 50 yards...then...USE the particular arrow that groups the TIGHTEST and most consistently for your INDOOR arrows at 20 yards. I think you'll be surprised at the improvement, and also which shaft is for "YOU" with that particular set up! MOST people "tune" their indoor arrows at ONLY 20 yards and call a 'bullet hole' "perfect"...WRONGO...not necessarily the case.
field14 (Tom D.)


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## nuts&bolts (Mar 25, 2005)

nimrod1034 said:


> Couple things
> 
> 1. This should be a sticky.
> 
> ...


I have a "free Guide to Tuning and Shooting Compound Bows"...here as a sticky on the Gen Section of AT.

http://www.archerytalk.com/vb/showthread.php?t=1399457

I cover the generic basics of most cam systems in the free guide.

Civil Engineer working at first in the CA State Dept of Health.
Developed a background in toxicology and engineering design.
Always fascinated by biomechanics. 25 years of designing complex systems
for folks like NASA and large companies. Now, working in medical devices (artificial spinal discs).

Built an indoor range for a buddy, so he could start his business a couple years back.
So, I have access to a 30 yard range, all to myself after hours. You can do hundreds of hours
of experiments, this way.


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## nuts&bolts (Mar 25, 2005)

field14 said:


> Do we dare talk about INTENTIONALLY "clocking" or "un-clocking" the cams to get better grouping, forgiveness, and performance out of your system?
> 
> OMG...then, in the "day" we INTENTIONALLY placed more 'pre-bend' into the limbs to improve performance regardles of the fact that limb-life was reduced by quite a bit.....We pretty much knew the limits in the amout of pre-bend a limb type would take (by brand of bow), and stayed on the edge of that limit...but would work with it until the bow settled down and we were getting the best performance, least vibration, tightest groups (sweet spot), and most forgiveness we could find for that setup and arrow combination.
> Wasn't done in a day and often times we didn't bother with PAPER TEAR...but went for the groups at 65 yards +, because if the bow grouped tight at 65 yards, 20 yards was a chip shot. We knew years ago that a 20 yard "tune" didn't cut it...for anything but 20 yards (if that), but a 65 yard tune or even a 40 yard tune was even tighter at 20 yards!
> ...



As always,
wise words from field14.

Group tuning at long distance is the goal.
All tuning methods (paper, walkback, modified french, bareshaft) are starting points.

The end result is what we are truly after.


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## field14 (May 21, 2002)

nuts&bolts said:


> As always,
> wise words from field14.
> 
> Group tuning at long distance is the goal.
> ...


Yeah, and I think many folks on here would be surprised to find that more than likely the FATTEST SHAFT...is NOT for them...without one heck of a lot of work on their FORM first. A famous coach says, "you CANNOT tune your bow properly until your FORM is corrected FIRST. Then you can get an accurate and reliable tune of the equipment."
So, IF you want to get that, you gotta lot of fixin' to do on YOURSELF first, and that includes proper FIT of the bow to YOU and not you to the bow!

field14 (Tom D.)


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## Outback Man (Nov 21, 2009)

Marking for future reference...Thanks.


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## Tnutz (Nov 28, 2009)

Is it safe to assume that a bow with slightly ******ed cams would be a little faster ?


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## field14 (May 21, 2002)

Tnutz said:


> Is it safe to assume that a bow with slightly ******ed cams would be a little faster ?


Maybe, maybe not....BUT, this could make the bow handle better, group tighter, and be more forgiving. I"ve had bows where going to a HEAVIER arrow has resulted in tighter grouping and INCREASED speed and forgiveness. Case in point. I had a pair of bows that were matched to the point of even the limb deflection being the same. One of them was setup and shooting exceptionally well with 1714's. SO, naturally I figured the other one would shoot 1714's...WRONG assumption. While that bow shot them nicely, it would not group anywhere near as tightly as the other bow would with that arrow. The first bow was all solid X's at 65 yards, while the 2nd one was shooting a few X's, solid 5's, and some edger 5's with that arrow. I then decided to go back up to the car and grab a set of 1814's I had up there and try those in the 2nd bow. I figured that since the 1814 was heavier, and larger in diameter that they'd still end up low in the bull at 65 yards. I shot my first 1814 and to my surprise, it hit at the bottom of the 3 ring, dead at 12 o'clock! Shot another arrow and hit the first one. Shot 6 shots, and there it was...all 6 arrows touching each other at the bottom of the 3 ring, but at 12 o'clock HIGH, not 6 o'clock low! That particular bow obviously was more efficient and shot tighter groups and with a tighter pin gap with a 1814 than a 1714. You go with what combination the bow liked, and that bow wanted 1814's. The other bow would NOT shoot an 1814 for crap...wouldn't even group with them; it wanted 1714's.

TIGHTER site mark gap with a heavier arrow by about 6 yards! I'll take it, and not argue. Shot mid to high 550's with both those bows, trading off from one tournament to the other; just remembered which one used 1714 and which wanted 1814. Shot pretty much identically after that, ha.


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## HC Archery (Dec 16, 2004)

Great stuff. When customers ask me how much further can MFG. go with bows.... well... plenty really. Especially factoring in overall quality control, string & cables and simply making bows even easier to tune, time and stay that way.


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## Randyz7 (Feb 5, 2011)

So if you have an old PSE single cam with the three pegs for the draw length on the cam, are you telling me that when i took it to the shop and they move it to a different peg that it coulda changed my timing and threw off cam starting position?? And if so, the only fix is to get different lenght strings??


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## NMP (Aug 6, 2003)

Randyz7 said:


> So if you have an old PSE single cam with the three pegs for the draw length on the cam, are you telling me that when i took it to the shop and they move it to a different peg that it coulda changed my timing and threw off cam starting position?? And if so, the only fix is to get different lenght strings??


Those cams were designed to be set to spec on the middle peg and then you change pegs for the + or - draw. You dont need to change anything else.


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## NMP (Aug 6, 2003)

Your nocking point may change though.


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## field14 (May 21, 2002)

NMP said:


> Your nocking point may change though.


Yep, you got it, your nocking point WILL change up or down depending upon which way you move from the middle peg. You MUST measure and record your previous nocking point BEFORE you move the string on the peg, along with your peep height. This will save you a lot of time and hassle trying to get the bow back into "tune". Poundage could change too, and LET OFF will change.

field14 (Tom D.)


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## huntertroy (Feb 16, 2010)

nuts&bolts said:


> The Hoyt hybrid cam system...all versions of the hybrid cam system...
> has these basic parts.
> 
> 1) buss cable (also called a yoke cable)...which has 3 end loops.
> ...


Is this method considered timing or syncing, neither or both? Sorry for the dumb question but im just trying to sort out any confusion i might be having
Thank you


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## Sackamous (Oct 26, 2009)

I have a question...
I went pull up the tune chart on a maxxis 31 2010. There is no specific module listed for tuning, or im not seeing in on the sheet. Does this mean it can be tuned with any module? If I am missing it and it says on it some wheres C or D like they were saying earlier and my cam is a number #3 mod A, does that mean im SOL for tuning unless I go buy a set of mods?


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## NRA republican (May 13, 2003)

Time at rest. Sync at draw. Right?


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## BowhunterCliffy (Feb 19, 2007)

nuts&bolts said:


> I have a "free Guide to Tuning and Shooting Compound Bows"...here as a sticky on the Gen Section of AT.
> 
> http://www.archerytalk.com/vb/showthread.php?t=1399457
> 
> ...


thanks for link to that guide. very informative for novice archers like me who want to learn to tune their own bows.:thumbs_up


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## CarlV (Mar 12, 2008)

Anyone got a picture to show the timing marks on a Hoyt C1/2+ ?

THanks


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## N7709K (Dec 17, 2008)

lots of hoyt cams don't have "timing" marks. 

the confusion comes from the schools at which everyone was taught.. you get that in working in a shop too. what every it is, the people that know what your talking about understand. the ones who don't, probably don't have a grasp on what you are sayin. 

n&b, its nice to want everyone to give a good explanation, but i guess i view it as if they need that broken down as that far then they probably shouldn't be attempting what they are doing. now i know i'm gonna get flamed, but if someone asked me to explain it... unless they asked how far to advance/set back the top cam i wouldn't mention it. 

so with a hybrid/cam.5 system since they are basically a tweaked single cam, can one one rule out part of the equation? sure cams can be under/over rotated, but as the strings/cables stretch how the cams are slaved together also changes. So if you time/sync at 100% new strings, in 2 months of heavy use one or both of those will probably be off, after a year even farther off, and so on until they life of the strings is exceeded.

now i don't bother with factory spec or any of that. only thing i worry about in that area is the max poundage. after that, i "sync" the cams i guess, i have always referred to and have know it as timing. Set the top cam fast by a couple twists. then its off to shoot the stings in. only once the strings are shot in do i even bother with the rest of it. After a week or so and few hundred to 1k shots i'll go through, fix cam lean in top and bottom cams, play with the advancement of the top cam to get a feel i like. if the cams are over rotated, well thats where they need to be for me to achieve the dl that i need so they don't get moved. How is this wrong according to what your(ken, and n&b) schools of thought are?


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## straddleridge (Apr 28, 2010)

I want to thank both "Nuts&Bolts" and "baldyhunter" for their contributions to this forum and their help in my archery learning experience. This is a valuable thread. 

My bow is a Mission UX2. It has the Mathews "Timing" holes but when I set my cam rotation starting position(Timing) I use a vernier caliper. The tips of the jaws fit nicely over the cam touching the cable on one side and the string on the other. I am usually able to get the top and bottom cams within .010". 

I am able to get level bare shaft flight and the BH and ATA are very close to Mission Specifications. Bare shafts hit with fletched arrows which are very close to Muzzy fixed blade broadheads. The only problem I have is my nocking point is lower than it should be in relation to my QAD hd pro rest. How do I fix this?


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## Trykon Mike (Aug 25, 2007)

I am in


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## nuts&bolts (Mar 25, 2005)

huntertroy said:


> Is this method considered timing or syncing, neither or both? Sorry for the dumb question but im just trying to sort out any confusion i might be having
> Thank you



Not a dumb question at all.

If you have a hybrid cam system...e.g. Hoyt Cam-1/2 system...
you have a buss cable (yoke cable..."Y" shaped cable with the THREE end loops)
you have a control cable (simple cable that ties the top and bottom cams together....TOTAL of TWO loops)
and you have a bowstring.

Synchronization means to move together...think synchronized swimming at the Olympics, where all the swimmers do the ballet in the water...moving together.

So,
we want the two draw stops on the Hoyt Cam-1/2 to hit the cables at the same time.
This is where you get that SOLID SINGLE wall feel.

If when you hit full draw,
and the wall feels SUPER MUSHY..SQUISHY...not hard at all,
then,
you KNOW that the draw stops are not hitting the cables together.

If you have a draw board,
this is easy to see.

If you do not have a draw board,
then,
have a 2nd person handy.

Draw the bow slowly, and when you feel the first BUMP,
stop drawing
and ask if the person sees a GAP between the draw stop (flat straight section) and the cable.

This GAP could be on top.
This GAP could be on the bottom.

This means that the cams are NOT working together correctly.

So,
you tweak the twists in the cables (you can twist the buss...you can twist the control...you can do a little of both)
until...

you get ONE solid wall,
and the draw stops (straight flat sections...BOTH hit the cables at the same time).


So,
this is synchronization.


So,
what is TIMING?


Well,
let's give you an example.

The bowstring WRAPS around the cams...both of them.


WHAT if we install a bowstring that is 2-inches TOO LONG?

If we have the bow sitting on the dining room table,
and the top cam is on the left
and the bottom cam is on the right....

with a TOO LONG bowstring,
the top cam on the left,
would rotate TOO MUCH in the counter-clock-wise direction

and

with a TOO LONG bowstring,
the bottom cam on the right,
would rotate TOO MUCH in the clock-wise direction.


So,
when the bowstring is TOO LONG,
the cam timing position (like a clock)
is no good.

Both cams will STILL hit the draw stops together...

but
when we have a bowstring that is TOO LONG,
the draw weight goes UP,
cuz the cams are rotated TOO MUCH
the radius is TOO LONG on the cam
and the limbs are bent more than factory spec.

The POINTY part of the cam is not in the position, that the factory wants,
when the bow is at rest.


So,
let's continue with this example.

What happens when the bowstring is say 2-inches TOO SHORT?

Well,
the top cam is to our left,
with the bow on the dining room table.

Top cam is rotated CLOCKWISE too much.
Bottom cam is rotated COUNTER-CLOCKWISE too much.

Draw weight is now LOWER than spec.


This is all cam timing.

What direction is the POINTY part of the Hoyt cam-1/2 pointing,
when the bow is at rest,
sitting on the dining room table,
with top cam on the left,
with bottom cam on the right.

TIMING.


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## chevman (Nov 3, 2006)

CarlV said:


> Anyone got a picture to show the timing marks on a Hoyt C1/2+ ?
> 
> THanks


 My 1 1/2+ cams dont have any marks. None that i can see anyway.


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## nuts&bolts (Mar 25, 2005)

N7709K said:


> lots of hoyt cams don't have "timing" marks.
> 
> the confusion comes from the schools at which everyone was taught.. you get that in working in a shop too. what every it is, the people that know what your talking about understand. the ones who don't, probably don't have a grasp on what you are sayin.
> 
> ...


Hello N7709K:

the Hoyt or any hybrid cam system only has 3 parts...

a) buss cable length
b) control cable length
c) bowstring length.

With these 3 parts,
YOUR method
and the JAVI method are actually the same steps....just in slightly different order.

I agree,
a hybrid cam system is a modified single cam. The idler wheel is non-round, on purpose.

The super long bowstring on a solo cam (front half with the d-loop and back half return portion)
are split into two pieces...bowstring for hybrid = front half of the solocam bowstring
and
back half of the solocam bowstring = control cable for the hybrid cam system.


I like to build a 10-inch floating yoke,
for the extra narrow angle at the bottom of the floating yoke.

Since I have the floater at full diameter, I can allow the bow to self tune for top axle lean.
Build it once, and fire a few shots, and the top cam lean self adjusts to ZERO.

If you build your own buss cable, with a few extra strands, and use top grade modern string materials,
the buss cable is actually pretty stable. So, I will do the JAVI method earlier...maybe after say 20 shots.

Using the JAVI method gets you into the ball park very quickly.

Creep tune, and maybe a half twist at most to a cable to get the cam timing (starting rotation position) correct.


I would like to believe,
that with a bit of help,
live advice through pm messages,
posting publicly here on AT,
live coaching in-person...

that anybody that has a desire, 
can learn how to tweak their own bow
and be successful.


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## BowhunterCliffy (Feb 19, 2007)

excellent thread. i am learning alot! some of you guys sure know your stuff! thanks for sharing!


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## N7709K (Dec 17, 2008)

i listed the bare bones descript, sometimes info is better said, lol. I have had them settle in 30-50shots but i give them a good week more for me than the strings. in that week unless its a bow that is just getting a new set, i learn the bow as well. i'll get a feel for the cams in several levels of sync/timing. I'm not up to date really on string material/methods so i get a little lost in that. after they have settled i'll creep tune if necessary, fine tune dl, play with the advancement of the top cam and groups/hold pattern. 

Does letoff have any influence on how you sync/time? same for valley/draw stops? I'm asking about hoyts, and specifically spirals. I shoot 55% with top cam advanced one or two twists(under 1/16th inch). My valley is much diff with an advanced cam and how the transition into the valley than when i used to shoot top 1 twist slow.


I would assume that if you run a higher strand count the longer the life of the string and the less/faster it settle(weight load is more distributed). The new set of strings i have coming is geared toward longevity for a high volume shooter so I'm very excited for that. I know that some fibers are for diff purposes and i know that they all react diff to diff types of bows/cams/shooters.

I run a static yoke so i can tune to top for lean, on some of the bows i have setup we have induced lean into the top cam towards the cables to firm up the wall and give much better contact. My current bow(ve+) setup and tuned very easy but my mom's pro elite took some work. I have found that a static yoke works better for my style, but i haven't tried a floating with long loops to settle the lean... yet. I currently purchase all of the strings that i use, but I and strongly leaning to investing in a jig and making them myself. To me its a way to learn my equipment better and also better my understanding of the tuning process.


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## nuts&bolts (Mar 25, 2005)

N7709K said:


> i listed the bare bones descript, sometimes info is better said, lol. I have had them settle in 30-50shots but i give them a good week more for me than the strings. in that week unless its a bow that is just getting a new set, i learn the bow as well. i'll get a feel for the cams in several levels of sync/timing. I'm not up to date really on string material/methods so i get a little lost in that. after they have settled i'll creep tune if necessary, fine tune dl, play with the advancement of the top cam and groups/hold pattern.
> 
> Does letoff have any influence on how you sync/time? same for valley/draw stops? I'm asking about hoyts, and specifically spirals. I shoot 55% with top cam advanced one or two twists(under 1/16th inch). My valley is much diff with an advanced cam and how the transition into the valley than when i used to shoot top 1 twist slow.
> 
> ...


Yup.

when you make your own string and cable sets,
you have much room for experimentation.

Your approach is perfect for the advanced shooter,
you shoot in the bow, and then fine tune to get the best results.

The Hoyt spirals and Hoyt Cam-1/2 system seems to usually work best
with the top cam hitting the cable first,
and a tiny gap on the bottom cam stop and cable...credit card thickness of a gap.

This might be a half twist away from both stops hitting at the same moment.
This might be a full twist away from both stops hitting at the same moment.

It REALLY depends on the twist ratio on the buss and control cable.

If you have your buss and control cable constructed with TIGHT TWISTS,
say the 1 TWIST per 1-inch of finished cable length...

then,
a HALF twist will move your cam rotation position MUCH MORE...


as compared to,
a buss or control cable constructed with long, looser TWISTS,
say the 1 TWIST per 1.5-inches of finished cable length...

then,
a HALF twist for this looser twist cable will move your cam rotation position MUCH LESS.


So,
a looser twist ratio in the cable
allows for a much FINER adjustment.


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## JOE PA (Dec 13, 2003)

Thanks to baldyhunter for the thread and nuts and bolts for all the great contributions. I do understand the difference between timing and synch. Also understand over rotated and under rotated. Both terms are logical. What I can't seem to understand is the way most on here refer to advanced and "word that may not be typed.":wink:

If you twist up the string so the draw weight drops, the draw length drops, and the arrow speed drops, how in the world can you call that "advanced."? When you twist up the cables (don't shoot singles myself, for some of what N&B was describing with the Apex 7 example), you raise draw weight, draw length and speed, and people refer to it as "word that may not be typed"? This only makes sense if the main goal you have in archery is to draw your bow from brace to full draw. That part is OK, I guess. The part I like is the part when I release the string and the arrow goes flying to the target. In that case, what people (on AT) refer to as "advancing" the cam, actually slows everything up. That part is what does not, and will not make any sense to me personally. Guess I will have to stick with under/over rotated.


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## hillwilly (May 20, 2011)

PSE NRG single cam from 2008 any info on adjusting draw length and stop position? thanks in advance


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## nuts&bolts (Mar 25, 2005)

N7709K said:


> i listed the bare bones descript, sometimes info is better said, lol. I have had them settle in 30-50shots but i give them a good week more for me than the strings. in that week unless its a bow that is just getting a new set, i learn the bow as well. i'll get a feel for the cams in several levels of sync/timing. I'm not up to date really on string material/methods so i get a little lost in that. after they have settled i'll creep tune if necessary, fine tune dl, play with the advancement of the top cam and groups/hold pattern.
> 
> Does letoff have any influence on how you sync/time? same for valley/draw stops? I'm asking about hoyts, and specifically spirals. I shoot 55% with top cam advanced one or two twists(under 1/16th inch). My valley is much diff with an advanced cam and how the transition into the valley than when i used to shoot top 1 twist slow.
> 
> ...


Static yoke is also just fine.

NEXT time your order a set of threads,
ask the custom string maker
to CONSIDER making the yoke cable legs say 8-inches long
or even 10-inches long.

The LONGER yoke cable leg length,
also allows a much FINER tune
to the top cam lean angle.


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## nuts&bolts (Mar 25, 2005)

JOE PA said:


> Thanks to baldyhunter for the thread and nuts and bolts for all the great contributions. I do understand the difference between timing and synch. Also understand over rotated and under rotated. Both terms are logical. What I can't seem to understand is the way most on here refer to advanced and "word that may not be typed.":wink:
> 
> If you twist up the string so the draw weight drops, the draw length drops, and the arrow speed drops, how in the world can you call that "advanced."? When you twist up the cables (don't shoot singles myself, for some of what N&B was describing with the Apex 7 example), you raise draw weight, draw length and speed, and people refer to it as "word that may not be typed"? This only makes sense if the main goal you have in archery is to draw your bow from brace to full draw. That part is OK, I guess. The part I like is the part when I release the string and the arrow goes flying to the target. In that case, what people (on AT) refer to as "advancing" the cam, actually slows everything up. That part is what does not, and will not make any sense to me personally. Guess I will have to stick with under/over rotated.


Just depends on your frame of reference.

If you advance the cam.....you are rotating the cams towards the riser?


Short-stringing will obviously, 
shorten the bowstring, 
reduce the draw length, 
and if you shorten the bowstring enough...

experience a drop in draw weight, and an increase in holding weight.
If you "slow down the cam"....you are rotating the cams away from the riser?


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## JOE PA (Dec 13, 2003)

nuts&bolts said:


> If you advance the cam.....you are rotating the cams towards the riser?


Forward (cable side) of the cam, or string (behind axle) side?


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## a/c guy (Nov 1, 2005)

nuts&bolts said:


> Just depends on your frame of reference.
> 
> If you advance the cam.....you are rotating the cams towards the riser?
> 
> ...


I'd like to get this right too.....
If you short-string the bow, you under-rotate the cam and ret--d it?
If you long-string it, you over-rotate or advance it?


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## N7709K (Dec 17, 2008)

the lobe of the cam would be rotated towards the riser


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## NMP (Aug 6, 2003)

hillwilly said:


> PSE NRG single cam from 2008 any info on adjusting draw length and stop position? thanks in advance


PSE website under support then under tune charts type in your bow and the tune info will come up with the dl and stop information that you need as well as string and cable lengths and the rest of the bows specs.


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## willie7018 (Mar 19, 2007)

great material!!!!


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## nuts&bolts (Mar 25, 2005)

a/c guy said:


> I'd like to get this right too.....
> If you short-string the bow, you under-rotate the cam and ret--d it?
> If you long-string it, you over-rotate or advance it?


Here is a photo from the JAVI thread.



















Same photo,
but I ADDED LINES,
so it is easier to see what JAVI is talking about.

BOTTOM row of photos are all of the top cam at FULL DRAW.

BOTTOM LEFT photo...top cam is "over-rotated"...at full draw...meaning that the cam has rotated too much, when at full draw.
So, OVER-ROTATED at full draw,
means the draw stop (straight flat section of the DL module is BENDING the cable).

BOTTOM RIGHT photo...top cam is "under-rotated"...at full draw...meaning that we have a cam that has NOT ROTATED ENOUGH, when at full draw.
So UNDER-ROTATED at full draw,
means that we have a GAP at the draw stop (straight flat section of the DL module is not reaching the cable...while the other end of the bow..the draw stop HAS reached the cable).



Soooo,
if we have a GAP on one draw stop....
and the other draw stop IS in contact with the cable...

we have draw stops that are OUT of BALANCE..
we have draw stops that are NOT working together...
we have draw stops that are providing a MUSHY WALL..
we have draw stops that are OUT of synchronization...

*out of synch = ONE draw stop touches the cable and the OTHER draw stop does not touch the cable (a gap).*



So,
when you short string a bow ON PURPOSE....

assuming the bow is on the dining room table
and the bowstring is going left to right
and the top cam is on the right....

(just like in JAVI's pictures above)...

so,
let's put a custom bowstring that is 1-inch TOO SHORT,
what happens to the top cam which is on the right of us?

Top cam will rotate COUNTER-CLOCKWISE, when the bow is at rest.
Short stringing brings the DL shorter.
Short stringing rotates the cam part of the way FOR US...while the bow is at rest.


So,
if the buss cable and the control cable are the correct length,
and we have the correct bowstring length...

so,
the cams hit the draw stops at the same time...we have synchronization.


So,
if we ON PURPOSE,
put on a bowstring that is 1-inch too short,
the TOP cam will rotate counter-clock-wise...with the bow at rest
and
the bottom cam will rotate clock-wise...with the bow at rest.

The two cams have been rotated TOWARDS full draw FOR US,
when you put on a SHORT STRING on purpose.

CAM timing (bow at rest) is no longer in the FACTORY preferred position,
*with an ON PURPOSE SHORT STRING...*
CAMS have a HEAD START...
*CAMS have "ad-vanc-ed" AHEAD of the correct cam starting rotation position,*
when you SHORT-STRING a bow.


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## huntertroy (Feb 16, 2010)

thank you to baldyhunter for starting such a informative thread and a special thank you to nuts&bolts for answering my questions in such great detail, it really helped me to understand so much and i appreciate your help and patience.
P.S. i spent my evening building a draw board


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## nuts&bolts (Mar 25, 2005)

Sackamous said:


> I have a question...
> I went pull up the tune chart on a maxxis 31 2010. There is no specific module listed for tuning, or im not seeing in on the sheet. Does this mean it can be tuned with any module? If I am missing it and it says on it some wheres C or D like they were saying earlier and my cam is a number #3 mod A, does that mean im SOL for tuning unless I go buy a set of mods?


Hello Sackamous:

Let's say you have the 2010 Maxxis 31, with the XTR #2 cam,
and you have the DL set at the 27-inch position, which is the "C" module position.

Sooooo,
the Hoyt Tune Chart says YOUR 27-inch DL XTR #2 cam Maxxis 31 should be set at an ATA = 30.25-inches.
the Hoyt Tune Chart says YOUR 27-inch DL XTR #2 cam Maxxis 31 should have a BH = 6-7/8ths inches.

So,
go through the JAVI method,
and set the ATA for 1/4-inch LONGER than factory spec...so, in THIS example...30.50-inches...by tweaking the buss cable (also called YOKE cable...cable with 3 end loops).

Take at least 10 twists out of your bowstring...so the cables are the ONLY thing holding your bow together...bowstring is loose and cables are the ones with tension.

Then,
go through the entire JAVI procedure.


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## baldyhunter (Jan 22, 2006)

Alright,
I made some draw force curves tonight in order to explain (at least partly) why all this timing hoopla is important. I may also divulge some "super tuner" secrets along the way. All of these DFC's are taken straight from the same bow (which would be my personal and favorite bow of all time LOL....Specialist) I wish I would have had more time in the shop but I just worked 13 hours and need some sleep....so these DFC differances aren't as drastic as I'd have like to make them and I couldn't get detailed ones but they'll suffice for explanation. DFC one (the one in this post) is a DFC that is about perfect from a draw cycle perspective. It is smooth, smooth, smooth. Notice how the ramp up section and the drop section at the front and back of the DFC are of equal angles. Also note how the front and rear transitions (this is the area that bridges the ramp up section and the drop section to the plateau) are very round, nice and smooth. The last thing you'll want to focus on is how long the plateau is. Consider that this represents how long you are actually drawing peak weight. The longer and flatter the plateau...the longer you are storing max energy during the draw cycle.


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## Boogels (Jan 4, 2008)

A very interesting and learnfull thread. Thanks to the partisipants for sharing great info.

I have a question or two for Nuts & Bolts.

On your reply on andvancing and ret^arding cams (cam timing) on a cam 1/2 system it sound like one can only do that with the string? Why not the cables?

When one lenghthen the string and "untime" the cams why can't one time it again by unwinding the bus and controll. Different ATA and brace height but why woudnt it be it time then when you set the cam orientation exactly as before the lengthening with the cables. It will only result in a lower poundage bow with a longer ATA and a longer draw?

My second question also regarding a Cam 1/2 system:

Andvancing the cams with the cables: What effect does it have on 1. Let off 2. Valley
Ret^rding the cams with the string: What effec does it have on 1. Let off 2. Valley

Thx


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## baldyhunter (Jan 22, 2006)

Now lets look at what happens to the exact same bow if we advance the cam too much (Add twists to the string). In this picture you'll really want to focus on two things. See first that there is a small "hump developing toward the rear of the draw cycle. It's a bit hard to see in this pic but it's there and would develop very rapidly past this point if I'd advance the cam farther. Have we ever heard of someone insisting there is a "Hump" in the draw cycle of any given bow...while the next person insists that is is flat and smooth with no hump. Well, here you can see the exact same bow....just timed a bit differently....it can have a hump...but it doesn't need to. Another argument against dealers just grabbing bows out of boxes and handing them to people LOL. Also, notice that we've lost the smooth transition at the back of the curve...it drops much more rapidly into the valley. If we keep heading in this direction it'll be very hard to pull the bow into the valley smoothly. One last thing to consider....if your peak weight on the bow is 65 lbs...how long are you pulling it? See that tiny blip towards the end of the cycle....less than that. when you get away from a flat DFC you are actually only pulling peak weight for one point along the curve...your not nearly storing as much energy as you can.


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## baldyhunter (Jan 22, 2006)

Now lets ****** the cams. Lets put 10 or 15 twists in the cables and see what happens. What you'll notice here is that the bow gets up to peak weight much more quickly. Look at the angles of the ramp up and drop off. You'll notice that the bow hits peak weight very quickly...but also starts into the vally more quickly. If I had a more detailed DFC you would also see the peak weight hits only for a split second right at the beginning of the plateau and fron there there is really a gradual slope downward till it gets a really smooth transition into the valley. Your still only drawing peak weight for a small fraction of the DFC.


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## baldyhunter (Jan 22, 2006)

The last DFC is where my bow sits right now. It is a bit advanced as you'll notice. This is because this is my indoor bow and I'm not as worried about speed performance as I am about hitting a very specific draw length. When you advance timing...you shorten draw length. One thing to remember is that draw force curves can be custom fit to the archer. People with shoulder problems often like peak weight to hit where they have the most leverage....you can make a DFC to help that. Some people are just interested in all out performance...there is really only 1 fastest setting for timing. Some people like myself are OK giving up a few fps to hit a certain draw length....you can do that as long as you understand what your giving up in performance. I frequently advance the timing of cams as they perform great that way to an extent. I never advance them to the point that a perceptable "hump" is felt before the drop into the valley....I'm going to bed LOL


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## fletched (May 10, 2006)

baldyhunter said:


> The last DFC is where my bow sits right now. It is a bit advanced as you'll notice. This is because this is my indoor bow and I'm not as worried about speed performance as I am about hitting a very specific draw length. When you advance timing...you shorten draw length. One thing to remember is that draw force curves can be custom fit to the archer. People with shoulder problems often like peak weight to hit where they have the most leverage....you can make a DFC to help that. Some people are just interested in all out performance...there is really only 1 fastest setting for timing. Some people like myself are OK giving up a few fps to hit a certain draw length....you can do that as long as you understand what your giving up in performance. I frequently advance the timing of cams as they perform great that way to an extent. I never advance them to the point that a perceptable "hump" is felt before the drop into the valley....I'm going to bed LOL


Was the cams TIMED at full draw so they hit the draw stops at the same time? lol


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## codykrr (Feb 6, 2011)

so here is a question. 

Are the "timing" marks one most bows actually referencing IBO settings? 

I have my assassin timed correctly, as the cables runs directly in between the timing marks on both cams. but since I shoot such a short draw(26.5) will this technically affect timing? 

I am going to be getting an invasion soon. I have read and been told that being I have such a short draw, its going to be a very aggressive draw with little to no valley. can this be adjusted via cam timing?


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## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> The last DFC is where my bow sits right now. It is a bit advanced as you'll notice. This is because this is my indoor bow and I'm not as worried about speed performance as I am about hitting a very specific draw length. When you advance timing...you shorten draw length. One thing to remember is that draw force curves can be custom fit to the archer. People with shoulder problems often like peak weight to hit where they have the most leverage....you can make a DFC to help that. Some people are just interested in all out performance...there is really only 1 fastest setting for timing. Some people like myself are OK giving up a few fps to hit a certain draw length....you can do that as long as you understand what your giving up in performance. I frequently advance the timing of cams as they perform great that way to an extent. I never advance them to the point that a perceptable "hump" is felt before the drop into the valley....I'm going to bed LOL


I have OVER-LAYED the first three DFC by Ken.


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## nuts&bolts (Mar 25, 2005)

codykrr said:


> so here is a question.
> 
> Are the "timing" marks one most bows actually referencing IBO settings?
> 
> ...


The IBO settings are simply 30-inches of Draw Length
and 70 lbs of draw weight.

The bowstring is probably bare...with as short a center serving as possible...no peep sight
and probably not even a d-loop,
to keep the bowstring weight at the bare minimum,
to boost the IBO speed rating.


So,
with a module DL system,
when you go from 30-inches of draw length
down to the shorter draw lengths...

the modules just stop the cam rotation EARLY.

So,
if the cam rotates say 270 degrees for a 30-inch draw length,
then...

the cam may only rotate 220 degrees for a 26.5-inch draw length.

Of course, I am just making up these angles, but you get the idea.


So,
if you want to do some "funny business",
you can SHORT STRING a bow on purpose (see the ADVANCE the cam DFC)
and install a LONGER DL module on purpose.

If you have a *VERY AGGRESSIVE cam*,
this technique will SMOOOTH out the draw cycle (you also lose draw weight).

So,
let's say you have *BAD shoulders*. The bow you are thinking about has a *crazy high 340 fps IBO rating*.
So, even at 60 lbs...the bow draws really *HARSH...hurts your joints*.

So,
say we have the factory bowstring
and factory specs
and the factory 26.5-inch DL module.

What if we *ON PURPOSE install the 27.0-inch DL module*
and
we have *baldyhunter* make up a custom bowstring that is *SHORTER on PURPOSE*,
to make the *27.0-inch DL module*
provide a *26.5-inch draw length*?

We have just SHORT STRUNG a bow (shorter than factory bowstring)
to get the ADVANCED CAM DFC,
which SMOOOTHS out the draw cycle.


This is only ONE example of what a tuner / bowstring builder like Ken (*baldyhunter*,
can do for you.

*SEE POST #100 for the SHORT STRING Draw Force CURVE...explanation.*....DFC #2 out of 3 Draw Force Curves.


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## JOE PA (Dec 13, 2003)

Very interesting stuff once again. With my bow that has Martin CAT cams, I followed nuts and bolts' advice and moved the module to a longer setting and twisted up the string to smooth out the hump at the back of the draw. In Ken's pics, it seems like it should have done the opposite. I will definitely get that bow on the press and play with timing the cams differently to see what can be done with it. Nice to have such an adjustable system. N&B, thanks for your detailed explanation of ad-van-ced. I understand what you are saying. The terms still seem bass ackwards to me, but I understand what you are saying.


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## spmnlvr (Apr 28, 2009)

Baldy_ awesome illistration of what your describing Thank you.  Could you post some speeds for the DFC's you posted? Just wondering how much of a differance in arrow speed occurs when playing with performance. Are we talking 2-4fps or 10-15fps? Let's say with an arrow that is 6g per lb. and a "normal" loaded string. I'm not looking for "IBO" test but more of a real world test.

Thanks again. This thread will be printed when it dies down.


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## spmnlvr (Apr 28, 2009)

Joe PA- I believe Nuts&bolts was one of the first people I PM'ed when I joined AT. I just got a new string and asked him to walk me through restringing my 09 Firecat(cat cams). He really helped me alot and opened my eyes to new boundries in archery. They really are awesome cams to play with.


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## Sackamous (Oct 26, 2009)

nuts&bolts said:


> Sackamous said:
> 
> 
> > I have a question...
> ...


Yes sir, Thanks for the quick explanation Nuts you are the man. I think you missed the point of my question though. My Maxxis is a #3 "A" mod 28", My Turbo will be a #2 "E" mod 28". My question is can I tune the Maxxis with the A mod or the Turbo with the E mod? In Javi's first set of directions it says to tune with the D mod... (Highlited)



JAVI said:


> posting the other information in the thread as well... Hope this helps...
> 
> Hybrid Cam Sync & Timing
> By Mike Javi.... Cooper​
> ...


So do I have to go buy D mods to tune my bows, or was this statemnt ment for a specific bow? Like I said I do not find anywhere on the tune sheet hoyt has for the maxxis any specific mod for tuneing. They have numbers for all the mods so can I just tune them with the mods thats already on them?
Oh an thanks for all the time you guys put in trying to explane this stuff so we can understand.


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## Boogels (Jan 4, 2008)

Tune it with your modules on the bow. Make sure your draw stop is in the corresponding slot.


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## N7709K (Dec 17, 2008)

For the maxxis, no... Tune at whatev mods you have in it currently.

So on the dfc's if you have the cams advanced you get s smoother draw. I'm guessing these are on a binary cam system? 

With my hoyts I have found advanced cams give a better draw, but a loss of speed. I have also found that the amount that the top can is fast/slow also has an effect on the perceived feel of the draw and the transition into the valley. 

For example my ve+ as thats the bow I currently shoot 98% of the time. If I have my spirals set so that they are not over rotated(advanced) or under rotated(slow) and I have them timed so they stops hit at the same time I get a draw that peaks slightly faster, a more even pull through the draw and a short transition into the "valley". This provides the best groups but the misses are farther out(good for fita games). If I put 1 twist into the control cable I get a completely diff feel. The bow peaks at about the same time in the draw it the transition into the valley is much slower and I can feel the cams hit with the top cam, then bottom cam. Provides pretty good shot pattern but less x's and more 10's. Top 1 twist slow provides a very good feel, but the groups although good are strung vertically.

So with a dfc, letoff will change the curve correct? 

With these change in dfc's and how the peak energy is stored/amount is this where we run int o issues with different bows favoring weak or stiff spine? And can one tune the bow and arrows to meet the "sweet spot" where spine and cam timing/sync are both at the optimal position for that shooter? I'm presuming yes, but I'm not sure.

How does peak weigh change as the changes are made to the dfc? Changing cable length, shorter = more preload so increases peak weight, longer = less preload lighter mass weight ... Correct?


Thanks, 
This has been a wealth of knowledge


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## JOE PA (Dec 13, 2003)

spmnlvr said:


> Joe PA- I believe Nuts&bolts was one of the first people I PM'ed when I joined AT. I just got a new string and asked him to walk me through restringing my 09 Firecat(cat cams). He really helped me alot and opened my eyes to new boundries in archery. They really are awesome cams to play with.


Agree 100%. Great info, well explained from N&B, always as if he is (patiently) talking to a friend. A few others (not on this thread so far) seem to revel in minutia in order to make themselves appear greater than the rest of the forum combined. Learned quite a bit from AT's members. Still some great stuff like Baldyhunter's thread here. Just have to find it among the bashing threads that go multipage because so many love to argue.


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## Logjamb (May 14, 2008)

nuts&bolts said:


> Yes, a compromise.
> 
> IN order to get my Apex 7 to hit a real world 29-inch draw length
> (it was drawing 1/4-inch on the LONG side)...
> ...


I was going to use this with my A7 and would like to know how much draw weight you lost on your A7 after getting DL to 29"


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## nuts&bolts (Mar 25, 2005)

Sackamous said:


> Yes sir, Thanks for the quick explanation Nuts you are the man. I think you missed the point of my question though. My Maxxis is a #3 "A" mod 28", My Turbo will be a #2 "E" mod 28". My question is can I tune the Maxxis with the A mod or the Turbo with the E mod? In Javi's first set of directions it says to tune with the D mod... (Highlited)
> 
> 
> 
> ...


JAVI says to tune to whatever info is provided by Hoyt in the tune charts.

Many of the Hoyt Cam.5 tune charts ONLY provide the ATA and the BH for the CAM.5 module,
set the the "D" hole. So, if you ONLY know what the ATA should be for the Cam.5 module set to the "D" hole,
gotta put the Cam.5 module in the "D" hole...that's all.

The Maxxis Tune Chart provides ALL the info.
The Maxxis Tune Chart provides the ATA and the BH for XTR #3 cam in the "A" setting, in the "B" setting, in the "C" setting...all the way up to the "E" setting.
Basically, the Hoyt Tune Chart for the XTR #3 cam says......the ATA and the BH does not change, for any of the modules. ATA is 31.25-inches for ALL settings. BH = 7 inches for ALL settings.

So,
just leave your module alone.

Take out 10 twists and make the bowstring LOOSER than normal.

Next, set the ATA at 1/4-inch LONGER than factory spec....so, set the ATA for 31.50-inches
by untwisting the buss cable (JAVI method) on the Maxxis 31.

Now, tweak the control cable twists, to that you get cam synchronization (draw stops hitting together at full draw).

Then, last thing to do is to tweak the bowstring length / twists,
so that you hit factory spec for AMO draw length...if that's what you want to do.
Module A is SUPPOSED to deliver 28-inches of AMO draw length,
so this means a real world tape measure measurement of 26.25-inches.....pivot point to center serving between the d-loop knots.

Then,


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## huntertroy (Feb 16, 2010)

Is it safe to say you get the most speed from a bow by slowing down the cams (********* them)


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## Boogels (Jan 4, 2008)

Boogels said:


> A very interesting and learnfull thread. Thanks to the partisipants for sharing great info.
> 
> I have a question or two for Nuts & Bolts.
> 
> ...


Anyone else with an answer?


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## nuts&bolts (Mar 25, 2005)

N7709K said:


> For the maxxis, no... Tune at whatev mods you have in it currently.
> 
> So on the dfc's if you have the cams advanced you get s smoother draw. I'm guessing these are on a binary cam system?
> 
> ...



SHORT string a bow, the draw weight goes down...
the holding weight goes up (usually)...if you short string the bow enough, to see this effect (holding weight)....
advancing the cam...starting the cam to rotates towards full draw EARLY...cuz the bow is at rest.

LONG string a bow, the draw weight goes up....
the "FAT" part of the cam is rolling AWAY from the riser, when the bow is at rest...
SLOOOOWING down the cam...making the cam start behind the starting line...when the bow is at rest.


But,
as Ken (baldyhunter) has shown you on the DFCs....

the "advanced" DFC and the "slooooowed down" DFC are no longer flat plateaus anymore.











DFC 1 (IDEAL DFC)............................Peak DW = 58.8 lbs
......................................................Holding Weight = 20.8 lbs
......................................................Stored Energy = 69.4


DFC 2 (SHORT STRING just a little).....Peak DW = 53.6
......................................................Holding Weight = 19.9
......................................................Stored Energy = 63.1
(yes, short string and you LOSE power)


DFC 3 (shorted the ATA noticeably).....Peak DW = 67.2
......................................................Holding Weight = 22.4
......................................................Stored Energy = 81.3


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## Sackamous (Oct 26, 2009)

nuts&bolts said:


> JAVI says to tune to whatever info is provided by Hoyt in the tune charts.
> 
> Many of the Hoyt Cam.5 tune charts ONLY provide the ATA and the BH for the CAM.5 module,
> set the the "D" hole. So, if you ONLY know what the ATA should be for the Cam.5 module set to the "D" hole,
> ...


Thanks a ton nuts this ansers my questions in full...


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## ex-wolverine (Dec 31, 2004)

*Ok I will bite-Let me first say that Ken and his explanation of DFC is excellent*



Boogels said:


> A very interesting and learnfull thread. Thanks to the partisipants for sharing great info.
> 
> I have a question or two for Nuts & Bolts.
> 
> ...


To answer your question, from my perspective

I’m going to get flamed for this and I mean no disrespect to N&B , JAVI or anyone else on here ...I have a lot of respect for both...This is my experience tuning hundreds of Hoyts…Keep in mind we all have our opinions on tuning methods…I have been watching this thread and have been waiting for someone to ask this question…Either I’m stupid or one of the few that have the stones to say Hoyt cam system tuning can be done and done well without using the JAVI’s method

Here is why

1. Un-twisting the string (in my opinion) takes out an important part of string stability, dimension and peep stability. String builders build strings to exacting specs with a twist rate that they feel will give you the best consistency and stability...You un-twisting the string, and then twisting back will not ensure that you will put the twist rate or the string back to the AMO standards that the builder built the string to.

2. If you have Strings and cables built to manufacture specs (sometimes they are wrong) you *shouldn’t* have to take out or put in more than a couple of twists here or there to get the cams timed/synced perfectly..And maybe put a twist in or out of the string to get the peep aligned...As a string builder and tuner I most always put more twists in the string, I never take twists out if I don’t have to.

NOTE: I do know of some pros that have their strings made short or twisted up short to increase brace height 

3. I have tuned hundreds of Hoyts and Hybrid Cam systems to peak performance and never, never un-twisted the string until it’s loose to get the bow tuned…
You can adjust cam timing/Sync with the buss and control cable, increase and or decrease cam orientation with the buss and or control...And I do, while at the same time getting to bow to the correct draw length , poundage , ATA and Brace

I will say that I have seen and have had funky cam orientation with a too long or way to short of a string…

Bottom line, if you have strings and cables built to exacting specs, you can have your bow tuned in matter of minutes with just a couple of twists here and there….

On a final note; Myself and a couple other builders have discussed this and we will not warranty our strings if you take all the twist out of them...Especially if you draw the bow at peak poundage with the strings untwisted until they are loose...We cannot guarantee that you will have the same length, twist rate and peep stability that was built into them when they were sent to you...

Again not saying that JAVI , N&B , or anyone here is wrong, just saying that timing and orientation can be done with the cables if they are built correctly…But hey you asked the question

Tom


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## nuts&bolts (Mar 25, 2005)

ex-wolverine said:


> On a final note; Myself and a couple other builders have discussed this and we will not warranty our strings if you take all the twist out of them...Especially if you draw the bow at peak poundage with the strings untwisted until they are loose...We cannot guarantee that you will have the same length, twist rate and peep stability that was built into them when they were sent to you...
> 
> Again not saying that JAVI , N&B , or anyone here is wrong, just saying that timing and orientation can be done with the cables if they are built correctly…But hey you asked the question
> 
> Tom


Hello Tom:

Brain FART on my part....since I build my own strings and cables.

I 100% AGREE with you...from a string builder's perspective.
JAVI makes his own strings and teaches folks how to do it as well.


So,
if a customer purchases a custom string from one of the excellent AT string-makers...

UNTWISTING and RE-TWISTING a bowstring is not a great thing to do,
and can make the string unstable...

cuz the custom string maker spent a LOT OF TIME
getting the twist tension perfectly even throughout the entire string...

BEFORE installing end and center servings.


So,
if folks want to get into the finer points of tweaking and tuning bows...
then,
part of this process, 
part of the learning experience,
will be to learn how to make your own strings and cables...

so you can learn what happens,
when you short string a bow on purpose,
when you try a shorter cable (buss cable) on purpose...

to get the three experimental draw force curves
that Ken (baldyhunter) provided to us.


If you are purchasing a fine, custom bowstring,
then....

the customer takes the risk,
when twisting or untwisting a bow string,
where the peep rotation may get out of balance.


I encourage folks to take the leap,
and build their own tuning equipment,
and build their FIRST bowstring, and then the second...and so on.

So,
if you try the JAVI method
or try to duplicate the three draw force curves
that baldyhunter talks about....

the cost of experimentation will be...experimenting with your bowstring.

Maybe you purchase TWO bowstrings....one to shoot with,
and....

one to experiment with. No guarantees,
on the peep rotation stability,
on the second string,
where you play with twisting and untwisting.

It IS fixable,
but it will take some effort.


----------



## jaredc (Mar 23, 2008)

ex-wolverine said:


> To answer your question, from my perspective
> 
> I’m going to get flamed for this and I mean no disrespect to N&B , JAVI or anyone else on here ...I have a lot of respect for both...This is my experience tuning hundreds of Hoyts…Keep in mind we all have our opinions on tuning methods…I have been watching this thread and have been waiting for someone to ask this question…Either I’m stupid or one of the few that have the stones to say Hoyt cam system tuning can be done and done well without using the JAVI’s method
> 
> ...


Good post Tom, I agree 100% and I don't mean any disrespect either as I have enjoyed many posts from N&B and Javi in the past. I have actually had customers who I have made strings and cables for as well as synched and timed their setups, who have got themselves in trouble with the Javi method. On more than one occassion customers have read this thread on AT and decided they better take matters into their own hands lol. These are the same people who return weeks later and say "I tried this method on AT and now my bow is totally screwed up, can you please put it back to where you had it as it shot great there". I always ask my customers what it was they were trying to achieve when I already had the cams synced and timed, dw, dl, ata, and bh in spec. They all respond by saying they just read on AT that this method is supposed to make their bows shoot the best they can etc. etc. Anytime I have a customer ask what my opinion would be if they were to buy a press I always respond by telling them that I think it is a great investment and a great way to get to know your equipment. I am all for Baldy's post as it is spot on and I am all for people learning how to tune and time their equipment, but I just don't think that the Javi method with todays compounds is necessary for achieving the final goal.


----------



## nuts&bolts (Mar 25, 2005)

jaredc said:


> Good post Tom, I agree 100% and I don't mean any disrespect either as I have enjoyed many posts from N&B and Javi in the past. I have actually had customers who I have made strings and cables for as well as synched and timed their setups, who have got themselves in trouble with the Javi method. On more than one occassion customers have read this thread on AT and decided they better take matters into their own hands lol. These are the same people who return weeks later and say "I tried this method on AT and now my bow is totally screwed up, can you please put it back to where you had it as it shot great there". I always ask my customers what it was they were trying to achieve when I already had the cams synced and timed, dw, dl, ata, and bh in spec. They all respond by saying they just read on AT that this method is supposed to make their bows shoot the best they can etc. etc. Anytime I have a customer ask what my opinion would be if they were to buy a press I always respond by telling them that I think it is a great investment and a great way to get to know your equipment. I am all for Baldy's post as it is spot on and I am all for people learning how to tune and time their equipment, but I just don't think that the Javi method with todays compounds is necessary for achieving the final goal.



Folks...

if you want to jump into the deep end of experimenting with your bows...

then,
part of the process will be learning how to make your own strings and cables.

I will make a TEST string and a set of TEST cables,
strictly for experimenting purposes
to come up with the string length
and to come up with the buss cable length
and to come up with the control cable length
that provides the results I am looking for.

If you want to shoot your bow at factory specs,
then,
purchasing a fine custom string and cable set is the way to go.


If you want to explore, jump into the deep end,
and do similar things to what baldyhunter is doing....

then,
it is best to make your own string and cable sets,
cuz this is the reason you do this...experiment with a string that is 1/4-inch longer or shorter
and see what happens. Experiment with a cable that is slightly longer or shorter
and see what happens.

Gotta crawl before you walk.
Gotta walk before you run.

First few times you try to experiment,
you may make mistakes along the way.


If you want to try tuning BEYOND factory specs...

then,
the best approach may be to purchase TWO strings,
and TWO sets of cables...

and just play with the "second" set,
to learn what baldyhunter is doing.


----------



## jaredc (Mar 23, 2008)

Thanks N&B I hope people take your suggestions to heart. If people want to venture into the deep end and are comfortable doing it then here is my suggestion: take your stock strings and go into the deep end with them. Once everything is perfect take them off your bow and have them measured properly and then build or order your new set accordingly. Great post with lots to think about!


----------



## jaredc (Mar 23, 2008)

lol I think we are all typing at the same time


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## kicker338 (Nov 30, 2008)

Thanks a ton Baldyhunter , N&B , Ex-wloverine and everyone els. This has got to be the thread of the yr. Only comment I will add to this thread , which I haven't seen yet is about the cam system used on the martim ryteras. When i got my alien x and started doing my own tuning and making my own strings was finding out the alien cam's had no timing marks. Timing was achieved by setting the strings and cables to exact factory specks , then synch. the cams


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## Boogels (Jan 4, 2008)

ex-wolverine said:


> To answer your question, from my perspective
> 
> I’m going to get flamed for this and I mean no disrespect to N&B , JAVI or anyone else on here ...I have a lot of respect for both...This is my experience tuning hundreds of Hoyts…Keep in mind we all have our opinions on tuning methods…I have been watching this thread and have been waiting for someone to ask this question…Either I’m stupid or one of the few that have the stones to say Hoyt cam system tuning can be done and done well without using the JAVI’s method
> 
> ...


Hello Tom,
Thank you for your informative reply and the insight into what a string builder see as incorrect handling of strings.

Also keep in mind I don’t poses the knowledge of the persons you mentioned by a long margin but this is my opinion.

I don’t use the JAVI method either simply because the parameters stated are too loose in my opinion to be guaranteed of getting the cam orientation (timing) and other details like the string length and cable length close enough to factory specs.

There is simpler and more precise method. 

I for one measure the string and control cable length and sync (learnt it is sync for the first time in this thread thanks to the OP) it with the buss cable at full draw. To me it is timing and synchronizing simply because it definitely set the cam orientation also when you sync the draw stop.

End of story. You are so close to factory spec as can be. 

If you are one of the lucky ones and you own a scale you can measure peak draw weight and adjust the bus cable to make max poundage and sync again with the control.

This to me this is a cam ½ system set to factory specs.

From here tuning for speed and proper cam orientation to fit you is all in the cables but it usually involves not more than 2 twists both ways to get there.

To keep your cam orientation (timing) correct you have to involve both string and cables when adjusting draw length from here. Unwind the string for a longer draw BUT also unwind the control and bus to time (set the orientation correct) and sync at full draw.

Like you I believe sync and timing is done with the cables. You “untime” the cams with the string whenever you alter the length from factory spec.


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## JOE PA (Dec 13, 2003)

Tried Baldyhunter's trick (the 3 draw curves) by untwisting my string, twisting up the cables (my own string and cables, not custom) and moving the mod to the next shorter one. I like the bow more than ever now. The CAT cams no longer seem like they are "loafing" in the first half of the draw, and the late hump is less noticeable. Not that much different than my Katera with Z3s was. The bow seems quieter, though it probably is my imagination. Unlike a single cam, it still hits the aiming spot through all the changes. Nice change for just RE-tardin' them cams. Oh yes, peak wt. also increased about 4#, but with the different draw, it is less noticeable.


----------



## nuts&bolts (Mar 25, 2005)

jaredc said:


> Thanks N&B I hope people take your suggestions to heart. If people want to venture into the deep end and are comfortable doing it then here is my suggestion: take your stock strings and go into the deep end with them. Once everything is perfect take them off your bow and have them measured properly and then build or order your new set accordingly. Great post with lots to think about!


EXCELLENT suggestions.

That is actually,
what I am doing with my new to me
Mathews Apex 7, with the "Barracuda" string and cable.

I am tweaking the "stock stuff" like crazy,
to correct the draw length to a real world 29-inch DL...on the dot,
and
trying to keep the cam timing position at factory spec.

Once I had the "working lengths" on the factory rigging,
then,
I started to make a custom cable...(finished that)
and
will move onto make a custom string,
once I finish / finalize twists and adjustments.


----------



## nuts&bolts (Mar 25, 2005)

JOE PA said:


> Tried Baldyhunter's trick (the 3 draw curves) by untwisting my string, twisting up the cables (my own string and cables, not custom) and moving the mod to the next shorter one. I like the bow more than ever now. The CAT cams no longer seem like they are "loafing" in the first half of the draw, and the late hump is less noticeable. Not that much different than my Katera with Z3s was. The bow seems quieter, though it probably is my imagination. Unlike a single cam, it still hits the aiming spot through all the changes. Nice change for just RE-tardin' them cams. Oh yes, peak wt. also increased about 4#, but with the different draw, it is less noticeable.


Interesting.

Never tried slooooowing down the CAT cams.

I had a FireCat and did the "advancing cams" thing....twisted the bowstring shorter,
and went to the next size up on module length (1/2-inch longer than desired final DL)
and fine tuned the DL with the draw stop. Takes out the "hump" this way as well,
and makes for a super SMOOOOTH draw cycle.

ALWAYS more than one way to tweak a bow,
especially if you are making your own rigging...

or,

as jaredc suggests...

tweak away with your stock string and cables...
and
when the bow is shooting the way YOU like...

setup the string stretching device,
use 1/4-inch posts,
tension to 100 lbs of tension
and get a post to post measurement
and provide this to your favorite AT custom string maker.


----------



## baldyhunter (Jan 22, 2006)

ex-wolverine said:


> To answer your question, from my perspective
> 
> I’m going to get flamed for this and I mean no disrespect to N&B , JAVI or anyone else on here ...I have a lot of respect for both...This is my experience tuning hundreds of Hoyts…Keep in mind we all have our opinions on tuning methods…I have been watching this thread and have been waiting for someone to ask this question…Either I’m stupid or one of the few that have the stones to say Hoyt cam system tuning can be done and done well without using the JAVI’s method
> 
> ...


 I'm backing you on this Tom. I've tuned many, many of these in the last 5 years and (while the JAVI thread is a great tool) I see no good reason to untwist the string.
Ken


----------



## Ezbagr (Sep 15, 2010)

I just recently had a reputable string maker from here on AT make me a set of cables and string for a 2011 Hoyt Element. I done some measuring and the ATA is 1/8-1/4 inch short. I did nothing to correct this. The only things that I did was take the upper cam lean out and then made the top cam stop hit a tick earlier than the bottom. Should I try to get the ATA corrected?
Also, what would the acceptable number of twists-untwists that a person could adjust brand new quality made cables-string to get bow to factory specs?


----------



## flag (Oct 4, 2009)

Where is the best place to buy that easton draw force curve mapper I think I'm going to get me a new toy or can it be done on a draw board with a scale and a yard stick


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## N7709K (Dec 17, 2008)

Ken, 

do you have a bow with spirals handy? I don't have a mapper at my disposal and it would be interesting to see what the dfc looks like for those cams.


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## nuts&bolts (Mar 25, 2005)

flag said:


> Where is the best place to buy that easton draw force curve mapper I think I'm going to get me a new toy or can it be done on a draw board with a scale and a yard stick


http://www.huntersfriend.com/products/archery/easton_gear/easton_bow_mapper_system.html

A bit pricey.


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## nuts&bolts (Mar 25, 2005)

Ezbagr said:


> I just recently had a reputable string maker from here on AT make me a set of cables and string for a 2011 Hoyt Element. I done some measuring and the ATA is 1/8-1/4 inch short. I did nothing to correct this. The only things that I did was take the upper cam lean out and then made the top cam stop hit a tick earlier than the bottom. Should I try to get the ATA corrected?
> Also, what would the acceptable number of twists-untwists that a person could adjust brand new quality made cables-string to get bow to factory specs?


If you are able to reach your max draw weight (see bow sticker)
then,
no need to adjust the ATA.

So,
if you have 60 lb limbs,
and you have your limb bolts at maximum,
and the scale reads 60 lbs,
then you are just fine.


----------



## Ezbagr (Sep 15, 2010)

Thanks nuts and bolts, about 1/2 turn out from bottom and right at 60 pounds.


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## JOE PA (Dec 13, 2003)

Just had a thought. Are there any possible nock travel issues when playing with cam timing with a cam.5 type hybrid? Nuts and Bolts mentioned that Apex and I had similar issues with some early singles (but most of them had horrid nock travel anyway). Everything I have tried with CPS system stuff didn't show any problems whether the cams were in the A position (advanced) or D or E position (the other thing) in terms of bare shaft flight. Would not think a binary or true dual would have issues. Probably not the cam.5 either, but I'm not sure if anyone had found problems or not (assuming they are synched properly).


----------



## N7709K (Dec 17, 2008)

Joe, 

i was wondering the same thing


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## baldyhunter (Jan 22, 2006)

OK,
Believe it or not I still haven't read all the posts on this thread so far....but I will soon....and I thought I'd muddy the waters a bit LOL. First off for all cam systems the optimal timing position is draw length specific. In other words, if you have a bow tuned by me or Crackers and your a 28" draw...and you sell it to someone that is a 29" draw...the tune is ( as far as performance goes) gone. This is always true. In general, the shorter the draw length...the more advanced the cams will need to be to find the optimal (performance wise) DFC.


Now let me tell you all a story about a tuner and a bow LOL. I thought I'd explain a real life tuning experience so you all can see some of the compromises involved in tuning. And I want you all to think hard about the way some of us hold factory specs sooooo Dear. Now I think you all should know how much I love Athens Cams. They are just soooo smooth and they are also quick and efficient. I'm not bashing at all and I'm not going to tell you anything they wouldn't tell you on the phone....but there string specs WERE a mess. They've taken them in house now and things are better. BUT, a few years ago they had issues. If you really know about timing and you know about performance tuning...you know to completely toss the sticker string and cable lengths from their previous model bows. With that being said, one of my best customers brings me an an accomplice 34 (absolutely fantastic bow) with 28" cams. Now the current ATA is 34 1/4". Its a 70 lb bow and it maxes out at exactly 70 lbs. Things look good at first glance but the draw does seem to ramp up awefull fast and you can tell it just peaks out fast then begins dropping rapidly into the valley. Also, the bow is slow when compared to IBO. So, I do a DFC and confirm my suspicions...the factory string specs are way off...this cam is way too far R e t a r d e d and needs advancing to get that speed and smooth draw (so nice that they often times come together). Now I begin twisting and twisting the factory string just to get the DFC where it should be. I think I honestly needed 25 or 30 twists! Now the DFC looks great...and the draw feels soooo buttery smooth. I love it....till I put it on the scale. As we all know the counterintuitive thing about twisting the string (shortening it) is that you bring ata down and you also DECREASE draw weight. So now I have a bow that feels great to draw and is very efficient...but its ATA is now 1/2" short and it is only maxing out at 67lbs! What to do to get that back? Well, if I want to keep the draw and efficiency...but increase draw weight...I need to bring ATA in....compress the limbs even more. So now I mark the timing on both cams as they are perfect and begin twisting up both the strings and cables together (the only way to keep the timing the same). I add probably another 15 or so twists to the string (you all should have seen how twisted up that poor string was LOL) and about ten or so to each cable. Now, finally, the timing is great, the draw is so smooth, the speed is awesome, and the bow is maxing out at 70.5 lbs...perfect!!!!!!!! Unless your one to fuss over factory specs LOL. Luckily with parallel limbs it's easier for us to do this stuff without changing brace height too much so that was close. Draw length was about dead nuts on because of how far I had to advance the cam from its original setting to get it right. But ATA was about an inch and a half short. Guy brought in a Accomplice 34 and I handed him back an accomplice 32.5. Needless to say I had to completely blueprint new strings and cables for his bow at that DL. He absolutely loved the bow BTW...couldn't believe how much smoother the already smooth draw was and we were shooting 8 to 10 fps faster than when he brought it in. I got a lot of Athens bows after that LOL.

It's getting way past bed time so I'm going to finish this. Sometimes, for everything to to work the best factory specs need to be trashed and you just need to tune the bow. With most of the new bows specs are actually pretty close and things aren't too much of an issue as most manufacture are privy to all this. Even with my beloved bowtechs though, in the short draw settings I really need to push the cables past the timing dots (advance the cams) and bring ATA 1/4" or more under the recommended specs to find everything my customers and I are after.

please discuss!
Ken


----------



## nuts&bolts (Mar 25, 2005)

baldyhunter said:


> OK,
> Believe it or not I still haven't read all the posts on this thread so far....but I will soon....and I thought I'd muddy the waters a bit LOL. First off for all cam systems the optimal timing position is draw length specific. In other words, if you have a bow tuned by me or Crackers and your a 28" draw...and you sell it to someone that is a 29" draw...the tune is ( as far as performance goes) gone. This is always true. In general, the shorter the draw length...the more advanced the cams will need to be to find the optimal (performance wise) DFC.
> 
> 
> ...


Hello Ken:

You have to do what you have to do.

As you CLEARLY understand cam design,
and draw force curves...

it IS possible to go beyond factory specs
and on occasion,
find the sweet spot....in your example, the Accomplice 34 became an Accomplice 32.5.

The key points:

70 lb limbs were still drawing 70 lbs, even with a 1.5-inch reduction in ATA.
You know that this is possible, cuz the cam starting rotation position was changed drastically.

Whenever you ADVANCE CAMS (shorten the bowstring)
a "harsh feeling" draw cycle will smooth out...(see Martin FireCAT cam system at stock specs).

The well discussed side effect of ADVANCING cams,
is that you lose draw weight.

I think it was jaredc.....who suggested,
do all the experimenting with stock string/cable sets
and then,
figure out where you need to be, even if the "stock" string is so twisted up,
that it has knots practically up and down the string.

Ken,
you are letting out all the "super tuner" secrets...or least,
quite a few.

Well done.

Alan


----------



## ex-wolverine (Dec 31, 2004)

Thanks Ken...

Keep it going....



baldyhunter said:


> I'm backing you on this Tom. I've tuned many, many of these in the last 5 years and (while the JAVI thread is a great tool) I see no good reason to untwist the string.
> Ken


----------



## kicker338 (Nov 30, 2008)

baldyhunter got a question for you. As I said in my previous post about the rytera alienx not having any timing marks , where els would you start other than going with setting the strings to the manufactures specks ? I have played with cam advancing and going the other way but often wondered if there was another starting point other than setting string and cables to specks.

Ask this question in response to your statment about tossing the manufacture specks.


----------



## turkeyhunter60 (Apr 19, 2010)

I'm in for the Thread.....


----------



## sab323 (May 30, 2003)

thank you for the clarification. i'm always learning on this site...


----------



## spmnlvr (Apr 28, 2009)

Because of this thread I've promoted myself from a fair tuner to a good tuner....LOL. Funny thing is, This is pretty much what I have been doing the whole time. Only know I'm starting to understand why it works. Before I just played until I liked what I felt.

I also wanted to write something so I don't keep re-reading the same posts....LOL. Thanks guys


----------



## Tater1985 (Apr 28, 2008)

baldyhunter said:


> Now let me tell you all a story about a tuner and a bow LOL. I thought I'd explain a real life tuning experience so you all can see some of the compromises involved in tuning. And I want you all to think hard about the way some of us hold factory specs sooooo Dear. Now I think you all should know how much I love Athens Cams. They are just soooo smooth and they are also quick and efficient. I'm not bashing at all and I'm not going to tell you anything they wouldn't tell you on the phone....but there string specs WERE a mess. They've taken them in house now and things are better. BUT, a few years ago they had issues. If you really know about timing and you know about performance tuning...you know to completely toss the sticker string and cable lengths from their previous model bows. With that being said, one of my best customers brings me an an accomplice 34 (absolutely fantastic bow) with 28" cams. Now the current ATA is 34 1/4". Its a 70 lb bow and it maxes out at exactly 70 lbs. Things look good at first glance but the draw does seem to ramp up awefull fast and you can tell it just peaks out fast then begins dropping rapidly into the valley. Also, the bow is slow when compared to IBO. So, I do a DFC and confirm my suspicions...the factory string specs are way off...this cam is way too far R e t a r d e d and needs advancing to get that speed and smooth draw (so nice that they often times come together). Now I begin twisting and twisting the factory string just to get the DFC where it should be. I think I honestly needed 25 or 30 twists! Now the DFC looks great...and the draw feels soooo buttery smooth. I love it....till I put it on the scale. As we all know the counterintuitive thing about twisting the string (shortening it) is that you bring ata down and you also DECREASE draw weight. So now I have a bow that feels great to draw and is very efficient...but its ATA is now 1/2" short and it is only maxing out at 67lbs! What to do to get that back? Well, if I want to keep the draw and efficiency...but increase draw weight...I need to bring ATA in....compress the limbs even more. So now I mark the timing on both cams as they are perfect and begin twisting up both the strings and cables together (the only way to keep the timing the same). I add probably another 15 or so twists to the string (you all should have seen how twisted up that poor string was LOL) and about ten or so to each cable. Now, finally, the timing is great, the draw is so smooth, the speed is awesome, and the bow is maxing out at 70.5 lbs...perfect!!!!!!!! Unless your one to fuss over factory specs LOL. Luckily with parallel limbs it's easier for us to do this stuff without changing brace height too much so that was close. Draw length was about dead nuts on because of how far I had to advance the cam from its original setting to get it right. But ATA was about an inch and a half short. Guy brought in a Accomplice 34 and I handed him back an accomplice 32.5. Needless to say I had to completely blueprint new strings and cables for his bow at that DL. He absolutely loved the bow BTW...couldn't believe how much smoother the already smooth draw was and we were shooting 8 to 10 fps faster than when he brought it in. I got a lot of Athens bows after that LOL.
> 
> It's getting way past bed time so I'm going to finish this. Sometimes, for everything to to work the best factory specs need to be trashed and you just need to tune the bow. With most of the new bows specs are actually pretty close and things aren't too much of an issue as most manufacture are privy to all this. Even with my beloved bowtechs though, in the short draw settings I really need to push the cables past the timing dots (advance the cams) and bring ATA 1/4" or more under the recommended specs to find everything my customers and I are after.
> 
> ...


Ken, 

Just wondering if you ever happened to check the deflection numbers on the bottom side of the limbs? I recall tuning a couple Accomplices that came in light on poundage, and I was kind of getting a mixed bag on limb deflections and string specs there for a while. 

I guess at that point it would just depend on whether the customer wanted a 67#/34" bow or a 70.5#/32.5" bow. Some customers will request i set poundage at a lower wt before shipping it back and it all works out, lol.

Sent from my ADR6350 using Tapatalk


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## baldyhunter (Jan 22, 2006)

One point of clarificaton!!! 
BALDYHUNTER IS NOT ENDORSING THE CHANGING OF SPECS FROM FACTORY!!

I have a very scientific method and do not experiment with factory specs at random. 

Also:
Don't worry Alan...I'm saving some "secrets" LOL


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## baldyhunter (Jan 22, 2006)

Tater1985 said:


> Ken,
> 
> Just wondering if you ever happened to check the deflection numbers on the bottom side of the limbs? I recall tuning a couple Accomplices that came in light on poundage, and I was kind of getting a mixed bag on limb deflections and string specs there for a while.
> 
> ...


They were correct. And the strings and cables were just a bit long (normal stretch). So, whoever set those string and cable lengths did not understand timing or were pressured to keep the bow at specs (34" and 70lb) and so had to keep ******ing the cam to get that....thus ruining peak efficiency.


----------



## ontarget7 (Dec 30, 2009)

baldyhunter said:


> OK,
> Believe it or not I still haven't read all the posts on this thread so far....but I will soon....and I thought I'd muddy the waters a bit LOL. First off for all cam systems the optimal timing position is draw length specific. In other words, if you have a bow tuned by me or Crackers and your a 28" draw...and you sell it to someone that is a 29" draw...the tune is ( as far as performance goes) gone. This is always true. In general, the shorter the draw length...the more advanced the cams will need to be to find the optimal (performance wise) DFC.
> 
> 
> ...




Some of the older Elites were the same way to get the speeds up. I look at factory specs as a basic guide line but do adjust from there to fit individual needs on occasion.

Good post Ken :thumbs_up


----------



## mikesmith66 (Aug 8, 2008)

So for the sake of the guys that are just getting into tuning their own bows, where does one start with a bow that has no reference marks on the cams ? Such as the Hoyt Alphaburner I just bought ? There are no marks on the spirals, or any of their new cams from what I've seen on dealer's racks. 

I basically check the ATA , brace and draw length while working the cables to synch the stops. Poundage is always last on my list, and I never worry about it a whole lot. 

Am I going about this the wrong way since I have no timing marks to start with ? 



nuts&bolts said:


> Most times.
> 
> Hoyt has reference marks for the Spiral cam system.
> 
> ...


----------



## hunt123 (Jan 17, 2009)

chevman said:


> I know this is asking a lot but you can always say NO!!. I have read Javi's version of tuning a hoyt cam1/2+. Could you do a step by step for us? I have two of them that i just got and want to check them out.


I just got through doing that to my Maxxis, thanks to N&B's help in another thread. My cams were synchronized (stops hit at the same time) but when I backed out the twists on my string I found my ATA was 1/2" too long. So the cam starting position wasn't right.

But note - the cams WERE syncronized. There didn't appear to be any way to tell if the starting position was correct until I untwisted the string and checked the ATA. I couldn't find any indicating reference points on the XTR cams. 

I twisted down the buss cable to get the ATA 1/4" long per Javi & N&B then twisted the control cable to sync the cams. It took one less twist for the control cable.

Then I twisted the string back to set the DL and everything's good now. At least until I can test it at distance outside.


----------



## hunt123 (Jan 17, 2009)

> No guarantees,
> on the peep rotation stability,
> on the second string,
> where you play with twisting and untwisting.


Very interesting. I found exactly that when I was done with the twisting/untwisting (Winners Choice). Peep seems to not be quite as rotationally stable.


----------



## hunt123 (Jan 17, 2009)

baldyhunter said:


> I'm backing you on this Tom. I've tuned many, many of these in the last 5 years and (while the JAVI thread is a great tool) I see no good reason to untwist the string.
> Ken


If you don't, how can you tell if the cam starting position is right if there are no indicators on the cam? I mentioned what I found in a post just above.

Could you take the string clear off to check what the buss cable is doing then put it back on after you set the ATA with the buss?


----------



## ontarget7 (Dec 30, 2009)

hunt123 said:


> Very interesting. I found exactly that when I was done with the twisting/untwisting (Winners Choice). Peep seems to not be quite as rotationally stable.


This is why *jaredc* suggestion about doing your twisting with the factory strings to get a specific tune you are looking for was good. Then proceed to take proper measurement when you are done and order strings and cables accordingly.

Good suggestion :thumbs_up


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## Padgett (Feb 5, 2010)

Just about the time I think i know what I am doing I read a entire thread like this 6 page one and find out I know next to nothing.


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## CarlV (Mar 12, 2008)

hunt123 said:


> If you don't, how can you tell if the cam starting position is right if there are no indicators on the cam? I mentioned what I found in a post just above.
> 
> *Could you take the string clear off to check what the buss cable is doing then put it back on after you set the ATA with the buss*?


Here is a good question and one that common sence seems to dictate would work just dandy.

Any of you super-tuners care to comment?

THanks.


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## nuts&bolts (Mar 25, 2005)

mikesmith66 said:


> So for the sake of the guys that are just getting into tuning their own bows, where does one start with a bow that has no reference marks on the cams ? Such as the Hoyt Alphaburner I just bought ? There are no marks on the spirals, or any of their new cams from what I've seen on dealer's racks.
> 
> I basically check the ATA , brace and draw length while working the cables to synch the stops. Poundage is always last on my list, and I never worry about it a whole lot.
> 
> ...


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## Boogels (Jan 4, 2008)

nuts&bolts;10627926731) said:


> Factory specs are the best STARTING point.
> ....Get everything to factory spec.
> ....Confirm that the bowstring is at factory spec, under 100 lbs of tension and using 1/4-inch posts inside the loops.
> ....Repeat for cables.
> ...


The problem I have with this is that when you shorten the ATA with your string only your poundage drops and you just might end up with limbs that snap on you and you dont know why because you are UNDER max weight.

My rule is to always rather tune down that up. What this means is put a shorter draw module on your cam 1/2 system if your draw is between the mod sizes and tune for a longer draw by advancing the cams by unwinding the string and time again with the cables by unwinding the cables. Why I call it tune down is because you tune to down the poundage and not up the poundage. That way you will never snap a limb...or leave it at factory spec and put a longer D-loop on the string.

Much safer this way.

I anyway always find n Hoyt to be more acurite and foregiving this way.


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## nuts&bolts (Mar 25, 2005)

Boogels said:


> The problem I have with this is that when you shorten the ATA with your string only your poundage drops and you just might end up with limbs that snap on you and you dont know why because you are UNDER max weight.
> 
> My rule is to always rather tune down that up. What this means is put a shorter draw module on your cam 1/2 system if your draw is between the mod sizes and tune for a longer draw by advancing the cams by unwinding the string and time again with the cables by unwinding the cables. Why I call it tune down is because you tune to down the poundage and not up the poundage. That way you will never snap a limb...or leave it at factory spec and put a longer D-loop on the string.
> 
> ...


Slowing down the cams is what happens, when you untwist / lengthen a bowstring.
Advancing a cam is what happens, when you short string or ADD twists to a string....shorten the bowstring, the cam starts rotating towards full draw part way, at rest.

Slowing down a cam will give you a different DFC than what happens at factory spec...(see baldyhunter Example DFC #3).
Advancing a cam will give you a different DFC (see baldyhunter Example DFC #2).

I don't believe baldyhunter has ever snapped a set of limbs, by going beyond the yield stress of the limb blanks.
I have yet to snap a set of limbs....at least, not yet....

Anyone who choose to go beyond factory specs,
must do so at their OWN RISK,
AND...

use a healthy dose of common sense...

or at least,
as in the DIY thread,
where CNC machinist is developing a new riser design,
use finite element analysis and Solidworks software,
to find stress concentration points in the riser and the limbs.


So,
advancing a cam (short stringing) works...within limits and common sense
sloooowing down a cam (long stringing) works...provides different results and can also work...

kinda depends on what you are looking for, Draw Force Curve wise.

Taking a 34-inch ATA bow
and short stringing down to a 24-inch ATA bow, will most likely end up in snapping limbs.

Clearly, for the Athens 34-inch ATA bow that baldyhunter was working on,
and converting to an Athen 32.5-inch ATA bow, was within the working limits of the limbs.

I have done similar things to a Martin FireCAT bow and adjusted the ATA down 1-inch less than factory spec,
at my own RISK, of course.


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## BigBird1 (Dec 10, 2002)

nuts&bolts said:


> The L6 cam system is a hybrid cam system.
> 
> Buss cable.
> Control cable.
> ...


N&B,
I enjoy your comments immensely and you obviously know what you're talking about.
However, the PSE L6 cam design is a little different than the typical Hoyt hybrid configuration.
The top cam takeup module is actually not a module at all but rather a 3 1/2" dia. wheel. There is no flat spot present but the cam has a timing mark to designate optimum rotation. The top and bottom cams also have an approx. 5" diameter. This combined with the 3.5" takeup wheel makes for an extremely smooth draw. This is one of the few bows I can shoot just about everyday and not tire my old shoulders out. It's simple to tune and actually has a great wall because of the bottom cam draw stop. IMO, this is a much improved design over a single cam because of the two cables as opposed to one for easier tuning. Yet, it has the advantages of the smoother draw of a single cam. I agree it's a hybrid design but it's a little different from the norm.


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## Boogels (Jan 4, 2008)

nuts&bolts said:


> Slowing down the cams is what happens, when you untwist / lengthen a bowstring.
> 
> *My bad. Its ret^arding*
> 
> ...


***


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## kicker338 (Nov 30, 2008)

baldyhunter said:


> One point of clarificaton!!!
> BALDYHUNTER IS NOT ENDORSING THE CHANGING OF SPECS FROM FACTORY!!
> 
> I have a very scientific method and do not experiment with factory specs at random.
> ...


baldy if you are refering to my post on factory specks i'm sorry , did'nt mean to come accrose that way. I brought this issue because , when I got my alien and started playing with the tuning I seen the question ask a few times on other threads about where the cams should be positioned when the bow was at rest. The only answers everyone got was to set strings and cables to factory specks. Was this the optimum position for the cams? Never seen an answer to that. I tried alot of differant cam timing , advanced and retared but don't have anything to plot the DFC so just used a scale on my draw board and feel of the drawand my chrono. Think I tried about everything including advancing one cam over LOL the other all done with factory string. All in all I learned alot. Sure love those timing marks on my destroyer though , makes timing alot easer. I've wandered at times if I was on the right track conserning cam timing and thanks to this thread you started I know i'm on the right track. Thanks again

Gordon


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## nuts&bolts (Mar 25, 2005)

BigBird1 said:


> N&B,
> I enjoy your comments immensely and you obviously know what you're talking about.
> However, the PSE L6 cam design is a little different than the typical Hoyt hybrid configuration.
> The top cam takeup module is actually not a module at all but rather a 3 1/2" dia. wheel. There is no flat spot present but the cam has a timing mark to designate optimum rotation. The top and bottom cams also have an approx. 5" diameter. This combined with the 3.5" takeup wheel makes for an extremely smooth draw. This is one of the few bows I can shoot just about everyday and not tire my old shoulders out. It's simple to tune and actually has a great wall because of the bottom cam draw stop. IMO, this is a much improved design over a single cam because of the two cables as opposed to one for easier tuning. Yet, it has the advantages of the smoother draw of a single cam. I agree it's a hybrid design but it's a little different from the norm.
> ...


NICE photos.

My photos that I posted were generic photos from the PSE technical info section.

These are REALLY nice photos of the L6 cam design.
Interesting concept. I agree, the L6 top cam / idler wheel is a HUGE step forward from the classic single cam 1 cable, 1 string design.


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## TOOL (Apr 11, 2006)

For those interested in plotting their DFC without a bow force mapping system, I would suggest the Ontarget2 software. It is very reasonably priced and is probably one of the more useful tools a "home tuner" could have. It has original DFC info. in the database and can be manipulated with data obtained from a digital scale and draw board so that you are able to visualize the changes your making. 

Also, the terms "advance" and "r*tard" will never mean the same to everyone and should be avoided. Point of reference dictates their meanings. Certain manufacturers like Elite will use the terms opposite to what is being described here (both valid). To avoid technical confusion, simple descriptions of cam position (in relation to the string for example) as N&B usually uses might be more clearly understood by the masses.:cocktail:


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## JOE PA (Dec 13, 2003)

L6 seems to work most like the Darton CPS rather than the Hoyt cam.5 or the other PSE cams. Timing for CPS and synch (if you can call it that) is not as critical as cam.5, IME. Would like to try one some day, but have to say they look great. CPS is very tunable and stable.


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## athomPT (Dec 14, 2008)

Okay I'm totally blow away with the knowledge in this thread. My question guys is where does someone start to begin to develop the wisdome you guys possess. I just started tinkering this year, bought a press, vise, etc. so pretty good at the basics like nocking point/peep and basic timing on solo cams. Shooting cam and 1/2 now so feel like I'm back to the drawing board  I want to be able to take my bow and tune it to perfection, but I have to admit I feeled overwhelmed when I look at this piece of equipment and it's many moving parts


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## nuts&bolts (Mar 25, 2005)

athomPT said:


> Okay I'm totally blow away with the knowledge in this thread. My question guys is where does someone start to begin to develop the wisdome you guys possess. I just started tinkering this year, bought a press, vise, etc. so pretty good at the basics like nocking point/peep and basic timing on solo cams. Shooting cam and 1/2 now so feel like I'm back to the drawing board  I want to be able to take my bow and tune it to perfection, but I have to admit I feeled overwhelmed when I look at this piece of equipment and it's many moving parts


Ask questions.

Build a simple bow press. The $20 pipe clamp press in the DIY section can be built with oak fingers, if you don't weld.

A simple spring scale (Viking 100 lb scale) is dead reliable...not as nice as a digital load cell with Digital Read Out Display, but will work (spring scale).

Take your current bow,
and attach a yard stick to the draw board,
and get spring scale readings for say every 2 -inches away from brace height, and plot the poundage versus distance info.
Build your own draw scale graph. The weight would be zero at brace height. Position would be zero. Two inches away from brace, record draw weight.
4 inches away from brace, record draw weight. You get the idea. See what your current settings deliver, in terms of the shape of a draw force curve.


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## spmnlvr (Apr 28, 2009)

nuts&bolts said:


> Ask questions.
> 
> Build a simple bow press. The $20 pipe clamp press in the DIY section can be built with oak fingers, if you don't weld.
> 
> ...


Again sooo simple. Why didn't I think of that. OK so If I do that^ What am I looking for? Longest power stroke? This goes back to the DFC's thar baldy showed in correalation to arrow speeds. Or is this just a personal "feel" tool?


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## nuts&bolts (Mar 25, 2005)

spmnlvr said:


> Again sooo simple. Why didn't I think of that. OK so If I do that^ What am I looking for? Longest power stroke? This goes back to the DFC's thar baldy showed in correalation to arrow speeds. Or is this just a personal "feel" tool?


So,
let's say your bow is tuned to factory spec.

Using a spring scale, and a draw board and a yard stick,
you can recreate what the $650 Easton Draw Force Mapper will do...
create a draw force curve graph. Now you have a starting point.

baldyhunter showed use FOUR draw force curves,
where DFC #4 is what Ken uses, for his indoor bow.

So,
with your cams synchronized,
twist up the bowstring say 1/4-inch shorter than your current draw length.
Creat the draw force curve, and you can see the shape of a "advanced cam - shorter string rotation" curve,
and you can FEEL the difference in the draw cycle. You should see that the draw weight also reduced a little bit.

The plateau...the top portion of the curve...the middle section of the draw cycle where the weight is kinda steady...
baldyhunter says to focus on the BEGINNING of the plateau and the END of the plateau..
focus on the transition points...is this a smooth rounded curve at the BEGINNING of the plateau...is this a SHARP transition at the BEGINNING of the plateau?










DFC #2 is an example where the bowstring was twisted shorter...no other adjustments.


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## nuts&bolts (Mar 25, 2005)

spmnlvr said:


> Again sooo simple. Why didn't I think of that. OK so If I do that^ What am I looking for? Longest power stroke? This goes back to the DFC's thar baldy showed in correalation to arrow speeds. Or is this just a personal "feel" tool?


These are baldyhunter's (Ken's) draw force curves.

DFC 1 = factory spec
Peak Wt = 58.8 lbs
Holding Wt = 20.8 lbs


DFC 2 = short string (cams advanced)
Peak Wt = 53.6 lbs
Holding Wt = 19.9 lbs


DFC 3 = cables are shortened significantly..just to prove a point
Peak Wt = 67.2 lbs
Holding Wt = 22.4 lbs


DFC 4 = a blend of short stringing (slightly) and cables shortened (slightly)...blend of DFC 2 and 3
Peak Wt = 55.1 lbs
Holding Wt = 20.1 lbs












THIS is what you are looking for.

1) LENGTH of plateau at the top of the DFC

2) POSITION of plateau....EARLIER in the DFC or LATER in the DFC

3) SMOOTHNESS of curve / transition at the beginning of plateau

4) SMOOTHNESS of curve / LACK or SHARPNESS at the end of the plateau

There is a give and take.

MOVE the plateau to occur EARLIER, you pay a price.

MOVE the plateau to occur LATER, you pay a different price.

NOTICE that the length of plateau is another price you pay.

ALL functions (items 1 through 4) are inter-related.


At the most basic level,
just focus on the BLUE rectangles,
which give you a FEEL for the length of the "flat" portion of the plateau.

If you learn to look for certain nuances...
you will see that the "plateau" is not truly level...but some are sloping downhill (left to right)...more so than others.


DFC #3 is NOT a curve you want...I believe baldyhunter did this one, JUST to PROVE a point.

DFC #1 is a nice one to try to achieve.
DFC #4 is also a nice one to try to achieve.

DFC #2 is another example of a DFC to just PROVE a point...not something you really want.


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## field14 (May 21, 2002)

Be thankful! Those of us that have been around for awhile learned our 'ropes' thru tripping and stumbling, through keeping our eyes and ears open, thru reading what LITTLE was published, and some of us, by taking the leap to join the PRO organization so that we could become part of the "in-crowd" when information sharing wasn't common-place and secrets were something that were kept. Little bits and pieces leaked out here and there, and some sharing was there, but only enough to give you a bit of a bump upwards...nobody was willing to give up ALL their little secrets...of course, we all know that all the secrets, even today are NOT shared, ha.

field14 (Tom D.)


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## spmnlvr (Apr 28, 2009)

OK so far so good(I think). How about this? How does the draw curve affect speed? Using Baldy's dfc's and adjusting the peak weight and holding weight the same for all four would we see a difference in arrow speed? In other words I don't want the weight to control speed(I know more weight more speed) I want the efficiency of the cams to control speed.

Does this make sense? or am I missing something and should demote myself back to fair.....LOL

I can understand why draw force curve is important for feel but I want to know if some people trade speed fior feel(at the same weight).


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## nuts&bolts (Mar 25, 2005)

spmnlvr said:


> OK so far so good(I think). How about this? How does the draw curve affect speed? Using Baldy's dfc's and adjusting the peak weight and holding weight the same for all four would we see a difference in arrow speed? In other words I don't want the weight to control speed(I know more weight more speed) I want the efficiency of the cams to control speed.
> 
> Does this make sense? or am I missing something and should demote myself back to fair.....LOL
> 
> I can understand why draw force curve is important for feel but I want to know if some trade speed fior feel.


Now,
we have to get into a bit of physics.

I was trying to avoid this part.

Total AREA UNDER THE CURVE,
is what is used to calculate the Kinetic Energy.

So,
if we want MAXIMUM speed,
then,
we want MAXIMUM AREA under the curve.

BEST curve for maximum speed would be a square wave....
VERTICAL ramp up (left hand side of the DFC)
VERTICAL ramp down (right hand side of the DFC).











So, back to DFC #1.
58.5 lbs DRAW WT
69.4 ft lbs KE
118.0% KE versus Draw Weight.

So, back to DFC #2 - short string effect.
53.6 lbs DRAW WT
63.1 ft lbs KE
117.7% KE versus Draw Weight.

So, back to DFC #3. Looks like twist up the cables way way too short...ATA much shorter than spec.
(this is a WILD GUESS on my part)
67.2 lbs DRAW WT
81.3 ft lbs KE
121.0% KE versus Draw Weight.

So, back to DFC #4.
55.1 lbs DRAW WT
65.8 ft lbs KE
*119.4% KE versus Draw Weight.*


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## spmnlvr (Apr 28, 2009)

So maximum speed is achieved by the longest power stroke which is also the harshest draw(opinion based)?

Let's say DFC #3 and #4 are identical draw weights.

Safe to say DFC#3 is the fastest but #4 only gives up 1.6% KE and has a much better feel??????Correct? So if DFC#3 is sending and arrow at 300fps then #4 would be about 295.2fps???

Baldy and N&B if I'm way off tell me and I'll stop asking questions......LOL


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## nuts&bolts (Mar 25, 2005)

spmnlvr said:


> So maximum speed is achieved by the longest power stroke which is also the harshest draw(opinion based)?
> 
> Let's say DFC #3 and #4 are identical draw weights.
> 
> ...


Nope.

DFC #3 and DFC #4 can NEVER have identical draw weights.

Remember, there is a price to pay.

When you twist up the cables so that ATA gets shorter,
the transition is very sharp at the beginning of the plateau...(you said powerstroke...but you really mean the top part of the DFC...plateau).

I THINK baldyhunter was using a 60 lb bow, so he twisted up the ATA much shorter than factory spec, with no adjustment to the bowstring,
to show you what happens. So, DFC #3 will not be something to try and achieve.

Draw force Curve 1 is a very nice DFC....nice flat plateau with good transitions.\

WHEN you short string (twist up the bowstring)
the ENTRY to the plateau is very ROUNDED...you are losing KE this way...less area under the curve.

As Ken showed us,
you can COMPENSATE by twisting up the buss cable to RESTORE some draw weight (yes...ATA will get shorter than factory spec)
and you arrive at DFC #4....

SURE, DL will increase some, with the shorter ATA...
but the DL increase from the shorter ATA is NOT equal to DL shortening from the bowstring twisting...

cuz, most typical cable to bowstring CAM ratios are on the order of 1:3.

1 twist to the buss cable has a DIRECT effect on ATA.
1 twist to the bowstring has a SLIGHT effect on ATA.

1 twist to the bowstring has a DIRECT effect on bow DL setting.
1 twist to the cable has a SLIGHT effect on bow DL setting.


Can't give you ALL the answers via short posts on AT.
Gotta break down and build a draw board,
and either purchase a load cell (recommend S-type) and a Digital Read Out (DRO) Display
and start making your own draw force curves
and
taking notes
and
developing a series of your OWN rules of thumb and observations.


If you want to learn MORE about riser design,
limb pocket angles,
finite element analysis,
static load diagrams,
cable to bowstring cam ratios...

look up the CNC Machinist thread in the DIY section.

http://www.archerytalk.com/vb/showthread.php?t=1630202


I provide some assistance with CNC machinst
in bow riser design / limb pocket angles / power stroke verus brace height relationships...
so that he is now up to Revision 4. The latest design is looking very close to final.


HINT: try shortening the ATA a little bit, and gain a little bit too much DL...a skosh MORE than desired.
..........try to shorten the bowstring length, a little, to work your way BACK to the DL setting you REALLY want.


So,
do you shorten the bow dL by 1/8th inch with extra twists in the bowstring
and
compensate with 1/4-inch extra DL by tweaking ATA...so you end up with a NET GAIN of 1/8th over factory DL specs? (this assumes desired DL is 1/8th longer)

So,
do you shorten the bow DL by 3/16ths-inch with extra twists in the bowstring,
and
compensate with 5/16ths extra DL by tweaking ATA...so you end up with a NET GAIN of 1/8th inch over factory DL specs? (this assumes desired DL is 1/8th longer)


What happens to the shape of the DFC, if you do option 1?
What happens to the shape of the DFC, if you do option 2?

Can you do this for a fixed cam solo system?..only have a string and a buss cable.
How about a binary system?..no buss cable...only 2 control cables...and a string.
What about a hybrid fixed DL cam system (spirals)?...got 3 variables here....buss cable...control cable...bowstring.
What about a module based hybrid cam system (Cam.5)?...got 4 variables here...DL module...buss cable...control cable...bowstring.


The basic concepts are the same.

The execution for each of the 4 systems above, will be slightly different.


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## S.Wells (Oct 30, 2010)

baldyhunter said:


> ..............it's not at all what you think it is LOL.
> 
> 
> 
> ...


Thank you KEN!!!!!!!!!!!


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## Fortyneck (Oct 8, 2010)

I don't want to mess with the drift of this pow-wow...too much. I think someone else asked a Q about this too.

nuts&bolts, you mentioned tweaking your Apex and having improved (more level) nock travel as a by-product/goal, is there anyway you can give us a break-down of how 

"super-tuning" your cams/strings/cables influences nock travel, and how these techniques are used to achieve optimal if not "level" nock travel for different cam systems

taking into account their relative ability to have level nock travel.


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## Outback Man (Nov 21, 2009)

OK...I'm trying to balance what I think I knew vs. all the info I'm gathering from this thread...help me apply it to the following situation...Got a new bow today...2012 Hoyt Alpha Elite #3 RKT cam 29.5" draw and 50-60# limbs. A2A is suppose to be 36" and BH is suppose to be 7" (orignally I thought they should be a little bigger on both of these, cause on the 2011 fuel cam tune charts the #3 cams had slightly bigger A2A and BH, but I had a member on here send me the tune chart info for the 2012 AE.) Out of the box my ATA was 37", BH was 7", and my max poundage wast 64#. I don't have access to a draw board, but using a draw check arrow the deepest part of the grip is right about 28.5" so my current DL would be long at 30 1/4" (did I do that right???) As it stands right now I've got no noticable cam lean and the draw stops are set so that the top stop hits just a hair before the bottom.

So...do I put twists into the buss cable and the string? The cable twisting will correct A2A and the string twisting will help the weight/DL right??? And add a little BH??? If so what is the proper ratio of cable twists to string twists? And as long as I don't adjust the control cable I won't change my draw stops hitting like they are...correct???

Not sure if I feel smarter or more confused... I like to over think stuff... Thanks.


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## flag (Oct 4, 2009)

Is there any programs that will make a graph for me if I plug in the numbers. I'm going to start tinkering on my draw board buy moving my cams and see what it does to the dfc and see what feels the best and how much speed is lost or gained and pick what I like best and pull my strings and measure them and build a set to match. Thanks nut & bolts and baldy hunter for sharing this knowledge I have been wanting to get my tunning to the next level so hoepfully this will help


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## copterdoc (Oct 9, 2005)

N&B, those DFC's are deceptive.

They are not graduated for distance. I promise that the actual SHAPE, did not change. Just the distance.

Pay attention to the relevant data, which is: peak draw force, holding weight, power stroke and stored energy. The "line" is flawed by computer processing.


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## baldyhunter (Jan 22, 2006)

copterdoc said:


> N&B, those DFC's are deceptive.
> 
> They are not graduated for distance. I promise that the actual SHAPE, did not change. Just the distance.
> 
> Pay attention to the relevant data, which is: peak draw force, holding weight, power stroke and stored energy. The "line" is flawed by computer processing.


100% correct. Funny. I just hopped on to clarify this. Be back in a jiffy.


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## Buster of Xs (Nov 28, 2008)

BigBird1 said:


> N&B,
> I enjoy your comments immensely and you obviously know what you're talking about.
> However, the PSE L6 cam design is a little different than the typical Hoyt hybrid configuration.
> The top cam takeup module is actually not a module at all but rather a 3 1/2" dia. wheel. There is no flat spot present but the cam has a timing mark to designate optimum rotation. The top and bottom cams also have an approx. 5" diameter. This combined with the 3.5" takeup wheel makes for an extremely smooth draw. This is one of the few bows I can shoot just about everyday and not tire my old shoulders out. It's simple to tune and actually has a great wall because of the bottom cam draw stop. IMO, this is a much improved design over a single cam because of the two cables as opposed to one for easier tuning. Yet, it has the advantages of the smoother draw of a single cam. I agree it's a hybrid design but it's a little different from the norm.
> ...


These cams are very similar in function to Darton's CPS cams with the round control cable takeup on the top and a single draw stop on the bottom, even the orientation marks.


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## stuckbuck (Dec 31, 2006)

Subscribed!


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## Boogels (Jan 4, 2008)

baldyhunter,

Many thx for your effort in giving us the draw curves. Very interesting and with lots of valuble info.

Im a bit of the track with your last diagram. The change in DFC in the 3 ilustrations is that the DFC when the advancing and ret^arding was done with the bowstring or will it be the same when done with the cables?


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## fletched (May 10, 2006)

field14 said:


> Be thankful! Those of us that have been around for awhile learned our 'ropes' thru tripping and stumbling, through keeping our eyes and ears open, thru reading what LITTLE was published, and some of us, by taking the leap to join the PRO organization so that we could become part of the "in-crowd" when information sharing wasn't common-place and secrets were something that were kept. Little bits and pieces leaked out here and there, and some sharing was there, but only enough to give you a bit of a bump upwards...nobody was willing to give up ALL their little secrets...of course, we all know that all the secrets, even today are NOT shared, ha.
> 
> field14 (Tom D.)


Ain't that the truth. Knowledge came slow in the old days. I learned a lot by trial and error and experimenting and by wasting money. The trouble today is the too much infomation too soon can be overwhelming. I never got to concerned about tweaking the dfc unless it effects the valley. I try to get good performance and adjust the poundage to make shooting comfortable. What is important is knowing what you like and adjust the bow to make it more shootable and then to leave it alone and shoot it. Constant messing around with a bow instead of shooting it can be counter productive.


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## spmnlvr (Apr 28, 2009)

Thanks for the answers. Always appreciate answers to my questions. I know I ask alot of questions. I do that until I understand. Appreciate your patience as well. I enjoy reading threads like this a learning.

I understand by manipulating the string/cables and adjusting the DFC you change the holding weight, peak weight, etc. My question is, is one "setting" alone(advanced, neutral, r e t a r d e d) faster then the others? So if the peek weight and holding weight were exactly the same for all 3 "settings". Would one be faster? Baldy kind of answered my question when he said DFC "are different on let down". I think that's what I'm interested in. Efficiency on release(arrow speed) not draw. 

I understand it may not be possible on one particular bow. I also understand that the test would be no good if we used 3 different bows(even if the were the same make/model/lbs,etc).

Thanks Baldy I've had a headache for 2 days.....LOL


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## Boogels (Jan 4, 2008)

fletched said:


> Ain't that the truth. Knowledge came slow in the old days. I learned a lot by trial and error and experimenting and by wasting money. The trouble today is the too much infomation too soon can be overwhelming. I never got to concerned about tweaking the dfc unless it effects the valley. I try to get good performance and adjust the poundage to make shooting comfortable. What is important is knowing what you like and adjust the bow to make it more shootable and then to leave it alone and shoot it. Constant messing around with a bow instead of shooting it can be counter productive.


I agree with you 100%.

After a moring of tuning, tweaking, sweating and gaining 1fps. I am still on the same sync and timing marks I marked a long time ago. I still use the same tuning methods. I still shoot with a left cam lean. I shoot with the bottom cam touching first. My DFC feels just like before ..smooth and easy. My bow still make IBO. My BH still hit 1" right of my FP at 20M BUT my bow is tuned to me and I shoot lights out with it up to my hunting distance and thats how my bow is goiing to stay


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## hunt123 (Jan 17, 2009)

Based on baldyhunter's DFC comments / drawing, then is it possible to reduce the "sharp" dropoff into the valley on my XTR Maxxis cam by r*tarding the cam? 

And would that be done by increasing or decreasing the 1/4" over spec ATA from N&B / Javi's protocol? By how much? Any other consequences of doing that?


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## Tater1985 (Apr 28, 2008)

flag said:


> Is there any programs that will make a graph for me if I plug in the numbers. I'm going to start tinkering on my draw board buy moving my cams and see what it does to the dfc and see what feels the best and how much speed is lost or gained and pick what I like best and pull my strings and measure them and build a set to match. Thanks nut & bolts and baldy hunter for sharing this knowledge I have been wanting to get my tunning to the next level so hoepfully this will help


Do a search for Tater's Archery Programs. I posted a file that has a couple useful Excel spreadsheets, onr of which has a DFC generator in it. Look for version 2.0 if you can.

Sent from my ADR6350 using Tapatalk


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## Tater1985 (Apr 28, 2008)

I dont know if it will let you access the fike without being an EAF user, but here is a link to v2.0.

http://www.elitearchery.com/forums/showthread.php?p=374233 

Sent from my ADR6350 using Tapatalk


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## copterdoc (Oct 9, 2005)

hunt123 said:


> Based on baldyhunter's DFC comments / drawing, then is it possible to reduce the "sharp" dropoff into the valley on my XTR Maxxis cam by r*tarding the cam?....


 No.

There is a lot of stuff in this thread, that is wrong. Particularly the stuff about "shaping" the DFC, by advancing and [email protected] the cams.

You can't change the shape of a cam's DFC, without physically changing the shape of the cam. However, you can change the length of the DFC, and adjust the draw length by moving the stops independently of the modules.

Basically, you are putting the DFC of a longer DL, into a shorter DL, or vice versa, by changing how many degrees the cam can rotate.


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## JOE PA (Dec 13, 2003)

fletched said:


> What is important is knowing what you like and adjust the bow to make it more shootable and then to leave it alone and shoot it. Constant messing around with a bow instead of shooting it can be counter productive.


Truth^


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## bustn'nocks (May 11, 2010)

Nicely Ranted.


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## baldyhunter (Jan 22, 2006)

copterdoc said:


> No.
> 
> There is a lot of stuff in this thread, that is wrong. Particularly the stuff about "shaping" the DFC, by advancing and [email protected] the cams.
> 
> ...


Always respect what you got copterdoc....shot you a pm.


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## copterdoc (Oct 9, 2005)

This is always going to be confusing, until you can really understand how a cam works. And why advancing them decreases draw weight, while [email protected] them increases draw weight.

It's all about how leverage is applied.
This a "normal" timing position for a cam at brace.








This is an advanced cam. Notice how much closer the cable is to the axle. That gives the cam more leverage from the start of the draw cycle, and it reduces the draw weight throughout the entire power stroke.


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## montigre (Oct 13, 2008)

fletched said:


> Ain't that the truth. Knowledge came slow in the old days. I learned a lot by trial and error and experimenting and by wasting money. The trouble today is the too much infomation too soon can be overwhelming. I never got to concerned about tweaking the dfc unless it effects the valley. I try to get good performance and adjust the poundage to make shooting comfortable. What is important is knowing what you like and adjust the bow to make it more shootable and then to leave it alone and shoot it. Constant messing around with a bow instead of shooting it can be counter productive.


I wasn't shooting in the old days, but I have been hearing alot about them. I agree with both of you, to a point....too much information too soon can be overwhelming and can divert one's attention away from what they should be focusing on--shooting their bow. However, there's the flip side of the coin. If a novice target shooter is fully reliant on a shop setting up their equipment and is unable to work on their own equipment, what happens to them when their harness stretches out a little past their optimum, or as their form improves or changes, the bow's specs have to be adjusted to accomodate and that shop is either not able or willing to devote the necessary time to properly set up the equipment for that shooter? Should the shooter just accept this as part of the "learning curve" or should they make an attempt to use the information that's now available to become more self reliant with regard to at least performing a basic complete tune of their equipment? 

Granted, that same novice shooter is not going to need to know how to tweak their equipment for superior performance until they're consistently shooting near perfect rounds indoors and are looking to up thier x count, or boost their field score into the 30s, 40s, or 50s. But knowing what to do to off set a bow's natural tendency to dive downward the harder they pull against the stops, or how to get a firmer back wall with cam.5+ systems if shooting a hinge release is something that would be very useful to that novice shooter and would aid in their becoming more confident in their equipment because they would have a greater understanding of how it functions and the relatedness of its parts. Yes, mistakes will be made in the beginning, but not all knowledge is bad as long as the primary focus of shooting the bow is not lost. :wink:


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## ex-wolverine (Dec 31, 2004)

You make a great point...

It is kind of funny how we all could find the sweetspot with just a bow scale , chrono and a measureing tape ...I also agree with you that we need to spend more time shooting than playing, its more fun

It is my opinion finding the Peak in the DFC dosnt always mean that you will enjoy shooting the bow...I have tweaked bows for maximum performance and they just felt like @$$ to shoot...

I have also found in quite a few cases that putting the bow to manufactures specs, is pretty darn close to what you guys are looking for, if not spot on...

Again, in my opinion you have to ask your self two questions when you are playing around with your bow...Do I want speed? or do I want shootability? There is a balance , but if you go over the edge trying to get more horse power, pay attention to how the bow draws, shoots, aims...And by the time you get the bow the way you want, you might be closer to factory specs than you think:wink:

If I were a betting man, most of the top shooters in the world, get thier bows the way the want and shoot and shoot and shoot, working on their form and execution...Thats how you up the x-count!!



fletched said:


> Ain't that the truth. Knowledge came slow in the old days. I learned a lot by trial and error and experimenting and by wasting money. The trouble today is the too much infomation too soon can be overwhelming. I never got to concerned about tweaking the dfc unless it effects the valley. I try to get good performance and adjust the poundage to make shooting comfortable. What is important is knowing what you like and adjust the bow to make it more shootable and then to leave it alone and shoot it. Constant messing around with a bow instead of shooting it can be counter productive.


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## baldyhunter (Jan 22, 2006)

ex-wolverine said:


> You make a great point...
> 
> It is kind of funny how we all could find the sweetspot with just a bow scale , chrono and a measureing tape ...I also agree with you that we need to spend more time shooting than playing, its more fun
> 
> ...


Maybe ironically I agree with both you and fletched. Notice my personal bows don't get as much attention as most the bows I tune. Here's the deal. Factory specs are generally very, close. With most the big manufactures....if we really spend a lot of time playing with timing...we only gain a few fps. Now with the Athens at the biginning of the thread, which was way off...I gained a lot and made the draw even smoother....win! win!. I never suggested people go out and try to supertune their bows. And in general it really isn't worth theffort unles you have the time, knowledge, equipment, and experience to do it. You also always want to check the gains your making in speed....versus the feel of the draw. One more time though, the point of the thread is that timing (within reason) is important to bow performance and how the draw feels, and is a completely different than synchronization. And, some people that have bows that are "out of wack" can have a better idea now of what timing does.


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## field14 (May 21, 2002)

I think that the words of a very, very prominent archery coach say all of this the best: "You CANNOT tune your bow properly until YOU have tuned YOURSELF first." FORM is everything, and if your form is constantly changing, then the bow is never being shot the same way twice in a row, let alone 60 times in a row. Too many people worry more about super-tuning the BOW, trying to make themselves fit the bow instead of the bow becoming fit to them, and almost ignore their FORM.
They'd be better off spending a few hundred bucks and some sessions with a good COACH...than spending way more than that with electronics, accessories, and fiddling with cables, strings, nocking points, different spines of arrows, etc.

This is all fine and good, and great stuff...but much easier to accomplish when the shooter has his/her poop together and a solid FORM and shooting base so their input into the bow is the same each time! A "hooter shooter" is NOT the answer to BOW tuning either!!! It might be great for getting the arrows to shoot into the same hole out of your bow, but for tuning the BOW "for" the shooter; I don't personally think that is the way to go.

field14 (tom D)


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## adam Guggisberg (Jan 28, 2003)

Going back to the original rant..  I agree with what you stated Baldy. Now... Do I want to explain that every time I talk to someone & then correct them every time they use the wrong terms? Not so much.. People "understand" timing to be "Do my draw stops hit at the same time?". And when I say "Cam Position is either advanced or underwrapped", they can understand that for the most part. 

Now the one area where I do have a pet peeve similar to yours is in the area of draw length. I always use Tru-Draw as the baseline in order to establish AMO. So when working with someone long distance in order to establish the necessary cam size for an upgrade Etc, this is my go to. "provide me with your current Tru_Draw measurement (Throat of grip to inside of string at full draw) & let's go from there. Without establishing that baseline, conversations about draw length & requested changes can be a night mare. 

With the draw length conversation it's not so much about a misuse of terms but more of a misunderstanding of what the words "Draw Length" means & in which context.

-Adam


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## ex-wolverine (Dec 31, 2004)

Its a great thread and I think folks wil gain a lot of info and understanding from it it that is for sure...glad you started it



baldyhunter said:


> Maybe ironically I agree with both you and fletched. Notice my personal bows don't get as much attention as most the bows I tune. Here's the deal. Factory specs are generally very, close. With most the big manufactures....if we really spend a lot of time playing with timing...we only gain a few fps. Now with the Athens at the biginning of the thread, which was way off...I gained a lot and made the draw even smoother....win! win!. I never suggested people go out and try to supertune their bows. And in general it really isn't worth theffort unles you have the time, knowledge, equipment, and experience to do it. You also always want to check the gains your making in speed....versus the feel of the draw. One more time though, the point of the thread is that timing (within reason) is important to bow performance and how the draw feels, and is a completely different than synchronization. And, some people that have bows that are "out of wack" can have a better idea now of what timing does.


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## adam Guggisberg (Jan 28, 2003)

field14 said:


> I think that the words of a very, very prominent archery coach say all of this the best: "You CANNOT tune your bow properly until YOU have tuned YOURSELF first." FORM is everything, and if your form is constantly changing, then the bow is never being shot the same way twice in a row, let alone 60 times in a row. Too many people worry more about super-tuning the BOW, trying to make themselves fit the bow instead of the bow becoming fit to them, and almost ignore their FORM.
> They'd be better off spending a few hundred bucks and some sessions with a good COACH...than spending way more than that with electronics, accessories, and fiddling with cables, strings, nocking points, different spines of arrows, etc.
> 
> This is all fine and good, and great stuff...but much easier to accomplish when the shooter has his/her poop together and a solid FORM and shooting base so their input into the bow is the same each time! A "hooter shooter" is NOT the answer to BOW tuning either!!! It might be great for getting the arrows to shoot into the same hole out of your bow, but for tuning the BOW "for" the shooter; I don't personally think that is the way to go.
> ...


I agree about the Hooter shooter. Useless for tuning a bow but great for tuning arrows. For me, it's a very expensive draw board...

-Adam


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## nuts&bolts (Mar 25, 2005)

copterdoc said:


> This is always going to be confusing, until you can really understand how a cam works. And why advancing them decreases draw weight, while [email protected] them increases draw weight.
> 
> It's all about how leverage is applied.
> This a "normal" timing position for a cam at brace.
> ...


Nice drawings.

Here is my Martin Razor X Shoot Thru....Cam WAY WAY Advanced (short string) experiment.

Super smooth, and dropped the draw weight.


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## field14 (May 21, 2002)

Adam, I really like your "rant" about the TRUE DRAW being the key element for draw length. Too many look at the limb tag and that is what they say is the bow's draw length...it most instances it couldn't be farther from the truth! MOST of the 'custom-made' bow manufacturers operate from the TRUE DRAW when you order their bows.
I never operate from my AMO; couldn't care less what the AMO is....bogus number, IMHO. I "transfer" my brace height to the inside of the riser and make a thin vertical line at that point. Sometimes, but less often than most think, that vertical line is in the middle of the arrow rest mounting hole; often times it isn't. Doesn't really matter all that much, since this vertical line becomes my CONSTANT and ONLY reference when I'm measuring the TRUE DRAW of MY bow. That reference point is what I use for measurements. Tips of the prongs on the arrow rest is fine...unless you move the arrow rest. That vertical line CAN change if I get careless and don't set the brace height/ata correctly on a string change...but then, it becomes MY fault, ha.

I agree that the hooter shooter is a very expensive draw board...and "arrow tuner", hahahaha, but I hear tell that there are a lot of pros using them for the purpose of tuning their arrows.

You do good work on your custom tuning, from what I hear...and you know what you are doing.

field14 (Tom D.)


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## Spikealot (May 27, 2009)

adam Guggisberg said:


> I agree about the Hooter shooter. Useless for tuning a bow but great for tuning arrows. For me, it's a very expensive draw board...
> 
> -Adam


+100


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## JAVI (Jun 19, 2003)

I think... too many folks worry too much about tuning the bow and not enough about tuning the arrow and themselves... 

I tell my students... learn to put all your arrows into the same hole.... then move your sights..


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## copterdoc (Oct 9, 2005)

I have seen that pic on the Martin Forum.

What was the let-off percentage, with the cams advanced that much?



nuts&bolts said:


> Nice drawings.
> 
> Here is my Martin Razor X Shoot Thru....Cam WAY WAY Advanced (short string) experiment.
> 
> Super smooth, and dropped the draw weight.


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## nuts&bolts (Mar 25, 2005)

copterdoc said:


> I have seen that pic on the Martin Forum.
> 
> What was the let-off percentage, with the cams advanced that much?


I have since sold the bow to a deserving AT fella.

I believe I had the draw weight down to the mid-40s
and holding weight was say 18-19 lbs.

So, roughly 57-58% letoff. Draw cycle was very smooth.
Cams do look rather unusual.


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## copterdoc (Oct 9, 2005)

nuts&bolts said:


> I have since sold the bow to a deserving AT fella.
> 
> I believe I had the draw weight down to the mid-40s
> and holding weight was say 18-19 lbs.
> ...


 So, advancing the cams that much, only made a 10% difference in the let-off percentage, right?


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## nuts&bolts (Mar 25, 2005)

copterdoc said:


> So, advancing the cams that much, only made a 10% difference in the let-off percentage, right?


I dont' have the bow anymore.
The draw weight dropped significantly,
and I was hoping to get the holding weight up into the low 20's,
but was not able to.


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## baldyhunter (Jan 22, 2006)

adam Guggisberg said:


> I agree about the Hooter shooter. Useless for tuning a bow but great for tuning arrows. For me, it's a very expensive draw board...
> 
> -Adam


put me in for a big X3 On the hooter shooter as well and I still agree with what you and field are saying. Also, as far as true draw length goes, advancing the cams enough to achieve true dl...without changing the mods...can garner some very nice results. Custom strings and cables may be required.


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## montigre (Oct 13, 2008)

Javi, so very glad to see you here. Hope all is well!! :thumbs_up


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## montigre (Oct 13, 2008)

adam Guggisberg said:


> Now the one area where I do have a pet peeve similar to yours is in the area of draw length. I always use Tru-Draw as the baseline in order to establish AMO. So when working with someone long distance in order to establish the necessary cam size for an upgrade Etc, this is my go to. "provide me with your current Tru_Draw measurement (Throat of grip to inside of string at full draw) & let's go from there. Without establishing that baseline, conversations about draw length & requested changes can be a night mare. With the draw length conversation it's not so much about a misuse of terms but more of a misunderstanding of what the words "Draw Length" means & in which context.


Oh, Adam....Please don't get me started on that one!!! People who shoot very well and have done so for a very long time can't come to a consensus regarding from what point on the bow the draw length should be taken, I've gotten from the center of the berger hole to the string, from the end of the riser to the string, and from the throat of the grip to the string....you can imagine what kind of (expensive) headache this creates--especially when changing cams and harnesses to accommodate the varying opinions..... 

Sorry, couldn't help myself....I'll give it back to ya


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## nuts&bolts (Mar 25, 2005)

montigre said:


> Oh, Adam....Please don't get me started on that one!!! People who shoot very well and have done so for a very long time can't come to a consensus regarding from what point on the bow the draw length should be taken, I've gotten from the center of the berger hole to the string, from the end of the riser to the string, and from the throat of the grip to the string....you can imagine what kind of (expensive) headache this creates--especially when changing cams and harnesses to accommodate the varying opinions.....
> 
> Sorry, couldn't help myself....I'll give it back to ya


Hello montigre:

AMO standard is to measure from the pivot point (deepest part of the grip)
to the center serving (inside edge) between the d-loop knots, if you use a d-loop.
Once you have this measurement, then ADD 1.75-inches to get the AMO DL setting of the bow.



Now,
whether to believe the DL mark stamped on the fixed DL cams....that is a another story.

I just purchased a 29-inch FIXED DL Mathews Apex 7.
The bow, limbs maxed out, ATA and BH are hitting factory spec perfectly...

delivers 29.25-inches of DL. 

So, the fix was an extra long custom buss cable,
in order to shrink the Brace Height by 1/4-inch,
so I could preserve the cam timing.

Then, built a custom, extra long bowstring to match.


So,
if anyone needs the CORRECT tune specs for cable and bowstring,
for a Apex 7, with the 29-inch FIXED DL cam,
I have it.


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## spmnlvr (Apr 28, 2009)

N&B I thought you were supposed to measure the draw length from the deepest part of the grip to below your nock point in a straight line. If you measure to your nock point then your measuring on a slope(/)??????


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## BTM (Dec 31, 2002)

Baldy: Now you need to somehow explain to 95% of archery magazine writers that sync does not equal timing. (You've covered one of my pet peeves. Thank you!)


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## hardy86 (May 30, 2011)

Thanks for all the information guys! I am still sorting through it and trying to understand it. When you refer to setting the bow up to factory specs is it done with the limb bolts cranked down (maxed out) or can they be turned down? I would think that it would have to be done maxed out and then when the poundage is lowered you let measurement be what they are going to be. If a bow is set up to factory specs then is it timed/cams in a neutral strating position?
thanks


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## nuts&bolts (Mar 25, 2005)

hardy86 said:


> Thanks for all the information guys! I am still sorting through it and trying to understand it. When you refer to setting the bow up to factory specs is it done with the limb bolts cranked down (maxed out) or can they be turned down? I would think that it would have to be done maxed out and then when the poundage is lowered you let measurement be what they are going to be. If a bow is set up to factory specs then is it timed/cams in a neutral strating position?
> thanks


Factory spec is an excellent starting point.

a) assumes limbs are at maximum
b) the Hoyt Tune Charts tell you what draw length module setting to use, when tuning to factory spec....for the Hoyt Cam.5 system


AFTER tuning to factory spec,
then...

adjust the limb bolts to the draw weight that works BEST for YOUR arrows...

if you have an adjustable draw length module, return the module to the DL setting that works BEST for YOU.


So,
yes,
if you drop the draw weight with the limb bolts,
the axles (top and bottom) do come closer together,
and
yes,
the bow DL setting will increase slightly...whenever you loosen the limb bolts for lower draw weight.


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## nuts&bolts (Mar 25, 2005)

spmnlvr said:


> N&B I thought you were supposed to measure the draw length from the deepest part of the grip to below your nock point in a straight line. If you measure to your nock point then your measuring on a slope(/)??????












Technically,
you are correct.

However,
for a 29-inch draw length,
and assuming a 3-INCH difference in elevation
between the bow hand pivot point on the grip
to the spot on your HEAD where you put the nock of the arrow...

the "slope" distance is 29.15476-inches......1 / EIGHTH inch difference.


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## copterdoc (Oct 9, 2005)

Well, I just got up from a nice long nap, following a short duck hunt, that ended with a swim in freezing cold water, and air temps in the high 20's.

I'm not quite ready to take on some of Baldy's misunderstandings, but I think I'm ready to talk about some of the stuff N&B has been saying lately.

Particularly, about the hows and whys of ATA, BH, and DL.

The below, lists a problem, solution, and a conclusion.



nuts&bolts said:


> ....I just purchased a 29-inch FIXED DL Mathews Apex 7.
> The bow, limbs maxed out, ATA and BH are hitting factory spec perfectly...
> 
> delivers 29.25-inches of DL.
> ...


While I am sure that N&B did in fact solve the problem, I am certain that his conclusion as to how, is wrong.

Here is a pic of two bows. The risers, limbs and cams are identical. The cams are timed the same. The cams are also in perfect sync.








The only difference between the two bows, is the limb pocket angle, ATA, and BH.

The bow on the right has an ATA of 30", and a BH of 8.25".
The bow on the left has an ATA of 34.75", and a BH 7.25".

Neither one of these bows were ever produced at these specs. I had to calculate the string and cable specs all by myself. Since I order my strings and cables and don't build my own, the penalty for error is about $80!

So, here are my first two questions for nuts&bolts.
(1.) What is the difference in the string and cable lengths, in order to achieve a 4.75" reduction in ATA, without changing the cam timing?
(2.) What was the difference in the draw length, following the 4.75" reduction in ATA, and 1" increase in BH?


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## forked point (Dec 27, 2010)

Great info! Im taking this strait to my shop.


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## copterdoc (Oct 9, 2005)

bump


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## hunt123 (Jan 17, 2009)

So why did you take them both so far out of manufacturer's spec? What results did you get?


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## copterdoc (Oct 9, 2005)

hunt123 said:


> So why did you take them both so far out of manufacturer's spec? What results did you get?


 If that question is pointed at me, I did it so I could switch from 13" limbs, and C cams, to 14" limbs, and B cams.

The bow on the left, has been my main deer killer for the last 4 years. 
My motive, was too many limb failures, with the 13" limb. I increased the ATA and switched to B cams, because I didn't want the performance loss, that came from the 1" reduction in power stroke.

I haven't hunted with the bow on the left. I just built that one, to see how much I liked a Bullet-X with a 30" ATA, for hunting.


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## Breathn (Jun 12, 2005)

Havnt you guys learned anything from AT,your bow is either in tune or not..its that simple...LOL

Very good thread,I could go on for days on this subject but dont have enough time to type that much.there is so much into getting a bows optimum performance but guys can do it at home..even if they dont build strings they can map there own and give the specs to a builder to build a perfect set..but one critical thing to keep in mind is end serving diamater as if your using stock strings to map them most stock strings have bigger end diameters where they transition from the loop,and a lot of todays bows that part of the string is in the cam track and will affect the way the cam is positioned..so thats something to consider when getting dimensions for new threads.


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## oldpro888 (Dec 31, 2010)

Most know I can shoot. I have never spent a lot of time experimenting other than rest tuning, draw stops hitting at the same time. I fear I may be missing something. I can easily shoot very high scores, but always drop one or two Xs. What would all this accomplish, and what is a good reference to start to do this extreme fine tuning? What would clue me in that I needed to do more?


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## copterdoc (Oct 9, 2005)

Well, I guess that N&B doesn't want to play.

So, I have a question for Baldy.

In your print offs from the Easton Bow Force Mapper, the power strokes are all 19", save one, which is 19.4".

When you advance the cams, the power stroke ALWAYS decreases. When you [email protected] the cams, the power stroke ALWAYS increases. But, yours did not. Why not? You had to have changed something else, other than just advancing or [email protected] the cams.


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## flag (Oct 4, 2009)

with what i have learned from this thread i started playing with my bows timing and done a dfc on my draw board and used word to make a graph and was surpised at the results i found that my bow likes the ata a 1/4in shorter and the cam very slightly advanced to get the best preformance and a very smooth draw and a better holding bow on target i couldnt get the full 70lbs but it maxed out at just about 69lbs so it was close enough and picked up 7fps over what i was shooting with a r*tarded cam and 70lbs at factory specs i twisted the string and cables to get what wanted then measured them and built a set to those measurements but handnt got to shoot it yet i would like to post the the different dfc graphs but cant figure out how to do it i just want to thank baldy hunter and nuts&bolts and everybody esle for sharing the info this has been one of the best threads i have read guys like you is what makes the site awsome thanks again


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## hunt123 (Jan 17, 2009)

flag said:


> with what i have learned from this thread i started playing with my bows timing and done a dfc on my draw board and used word to make a graph and was surpised at the results i found that my bow likes the ata a 1/4in shorter and the cam very slightly advanced to get the best preformance and a very smooth draw and a better holding bow on target i couldnt get the full 70lbs but it maxed out at just about 69lbs so it was close enough and picked up 7fps over what i was shooting with a r*tarded cam and 70lbs at factory specs i twisted the string and cables to get what wanted then measured them and built a set to those measurements but handnt got to shoot it yet i would like to post the the different dfc graphs but cant figure out how to do it i just want to thank baldy hunter and nuts&bolts and everybody esle for sharing the info this has been one of the best threads i have read guys like you is what makes the site awsome thanks again


Very interesting! Yes, those two know what they're talking about. PM me and I'll post the graphs for you. They may need to be converted or something.


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## copterdoc (Oct 9, 2005)

I don't know just how involved I want to get in this thread.

This is some tough stuff to illustrate, in a way that doesn't come out all convoluted and confusing. Also, since this is a deeply rooted "voodoo magic" bow tuning topic, the people that feel strongly about it, are just going to stick to their beliefs, and get defensive.

I think that I am "safe" by just listing a few "rules", that I have found to be measurable, repeatable and applicable.

(1.) Advancing the cams, increases the cam's mechanical advantage. This reduces the amount of force on the string, required to compress the limbs. It lowers the draw weight.
(2.) Advancing the cams, decreases the total number of degrees, that they rotate from brace, to full draw. This shortens the power stroke, and thus shortens the draw length.

[email protected] the cams, does just the opposite.

The only way to advance or [email protected] the cams, is to change the relationship between the string length, and the cable length. There is more than one way to do THAT, though, and each one effects something else.

Adjusting cam timing, effects a number of measurements. We need to make sure that we identify what we changed, before we can say that we made a desirable change.

If you shorten only the cables, you will [email protected] the cams. Shortening the cables, decreases the bow's full draw ATA, the exact same amount. For instance, if a bow has a full draw ATA of 31", and you shorten the cables 1/4", it's "new" full draw ATA will be *EXACTLY* 30.75". The difference in ATA at brace, depends on the cam, but it will be a fraction of the amount that the cables were shortened.

If you only lengthen the string, the bow's full draw ATA, will be exactly the same. However, the draw weight will increase, because you gave the cam a lower mechanical advantage. You lengthened the lever arm of the cable track(s), and shortened the lever arm of the string track. At *EVERY* point of the draw cycle.

If you look at a draw force curve graph, the horizontal graduated line is distance, and the vertical graduated line is weight.

At the beginning portion of the draw cycle, the draw weight quickly climbs in the first few inches. This happens, before the cams even start to rotate. If you increase the bow's draw weight, by adding limb pre-load, or [email protected] the cams, this line becomes steeper. 

If you increase the draw weight by [email protected] the cams, and then reduce it back to what it was before, by reducing limb pre-load, guess what?
That steeper line at the beginning of the draw cycle, goes right back to where it was before. The only reason that the DFC *SEEMED* to change, was because the draw weight was increased.

You would have seen the exact same "change" to the DFC, if you hadn't even twisted a thing, but had just cranked down on the limb bolts.

Now, on to the valley end of the draw cycle.

Since the [email protected] cams are rotating a greater number of degrees during the draw cycle, they are feeding out more inches of string, between brace and full draw. This causes the power stroke to increase in length, and thus the draw length is longer. The cam(s) are still stopping at the same, exact position, that they did before they were [email protected] So, the "back end" of the DFC, is going to be exactly the same as it was, before the cams were [email protected]

It is the things that are done to stop the cams "sooner", that change the length of the valley.

The bottom line to all of this, is that if we play with our cam timing, and find a "sweet spot", that yields better performance, it is because we either increased the length of the power stroke, or we increased the draw weight.

It had nothing to do, with "shaping" the bow's DFC.


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## RIVERTHIEFFALLS (Apr 30, 2010)

Good thread!!!!!


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## copterdoc (Oct 9, 2005)

Adjusting cam timing is valuable. It allows us to increase or decrease the length of power stroke, and increase or decrease the bow's peak draw weight. There are some cams, that when set at the longer end of the DL range, develop a "hump", due to the change in module position, relative to the string track.

We can [email protected] those cams, and still reach OUR draw length, and move the module out of the "bad place", that the hump "appears". [email protected] the cams didn't change the shape of the DFC though. It merely lengthened the power stroke. We just stopped the cam's rotation sooner, before it reached the point that it's geometry caused something that we didn't desire.


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## Jerry/NJ (Jan 17, 2003)

copterdoc said:


> Adjusting cam timing is valuable. It allows us to increase or decrease the length of power stroke, and increase or decrease the bow's peak draw weight. There are some cams, that when set at the longer end of the DL range, develop a "hump", due to the change in module position, relative to the string track.
> 
> We can [email protected] those cams, and still reach OUR draw length, and move the module out of the "bad place", that the hump "appears". [email protected] the cams didn't change the shape of the DFC though. It merely lengthened the power stroke. We just stopped the cam's rotation sooner, before it reached the point that it's geometry caused something that we didn't desire.


 Good info copterdoc but I'd like to make a suggestion to you or whoever is good with pics on here and that is to show a pic(s) of cam(s) showing what advanced and ******ed means. I am sure many on here are watching and learning from this thread but something simple to us as ******/advance may confuse someone and them not want to say. I'd do it if I knew how to with a program that can edit pics. 
A good thread !!! 

Edit, the stars = r e t a r d e d


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## copterdoc (Oct 9, 2005)

Jerry/NJ said:


> Good info copterdoc but I'd like to make a suggestion to you or whoever is good with pics on here and that is to show a pic(s) of cam(s) showing what advanced and ******ed means. I am sure many on here are watching and learning from this thread but something simple to us as ******/advance may confuse someone and them not want to say. I'd do it if I knew how to with a program that can edit pics.
> A good thread !!!
> 
> Edit, the stars = r e t a r d e d


 There already is. Post #196, shows a neutral, and an advanced cam position. [email protected], is the opposite of advanced.


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## Jerry/NJ (Jan 17, 2003)

copterdoc said:


> There already is. Post #196, shows a neutral, and an advanced cam position. [email protected], is the opposite of advanced.


My bad, I skipped some pages, lol.....thanks!


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## baldyhunter (Jan 22, 2006)

copterdoc said:


> Well, I guess that N&B doesn't want to play.
> 
> So, I have a question for Baldy.
> 
> ...


Copterdoc....I want to play !!
Just no time right now. I did try and post up a quick reply yesterday but my internet connection was messed up. I'll read the thread later tonight and see what you've got.
Thanks
Ken


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## flag (Oct 4, 2009)

im still trying to figure out how to post my results but cant figure it out but the results werent that much different other than it held the poundage longer through the power stroke then whe i r*tared the the cam it spiked higher then dropped weight and the picked it up again it was not a smooth draw and the dfc showed it when i put it in the neutral posistion it showed the best dfc and it shot good but the poudage was off so i compressed the limbs a little more and got it close to max poundaged and it shot around 7fps faster like that than it did at factory specs its not faster than the ibo of the bow just 7fps faster than it was set up the other way the gain of a couple of pounds is probally the difference but it draws and holds alot better now does anybody know how to post a word file as a picture so i can show the difference


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## chaded (Jan 15, 2011)

This thread is a good example why I'm glad to have Baldy's so close to me.


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## WVaBuckHunter (Sep 30, 2010)

Let's bring this one back up.


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## hunt123 (Jan 17, 2009)

flag said:


> *im still trying to figure out how to post my results* but cant figure it out but the results werent that much different other than it held the poundage longer through the power stroke then whe i r*tared the the cam it spiked higher then dropped weight and the picked it up again it was not a smooth draw and the dfc showed it when i put it in the neutral posistion it showed the best dfc and it shot good but the poudage was off so i compressed the limbs a little more and got it close to max poundaged and it shot around 7fps faster like that than it did at factory specs its not faster than the ibo of the bow just 7fps faster than it was set up the other way the gain of a couple of pounds is probally the difference but it draws and holds alot better now does anybody know how to post a word file as a picture so i can show the difference


You did see my offer earlier?


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## peregrine82 (Aug 25, 2007)

This has probably already been addressed. Why is Elite's advancing the cam terminology directly opposite to what everyone uses. They may not be the only one doing this but it can get confusing.


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## JOE PA (Dec 13, 2003)

peregrine82 said:


> This has probably already been addressed. Why is Elite's advancing the cam terminology directly opposite to what everyone uses. They may not be the only one doing this but it can get confusing.


Not sure why, but referring to it that way actually makes more logical sense that what everyone else uses. At least you know what they are talking about. Reminds me of where I used to work. Common saying was "We can't do it that way, because it makes too much sense."


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## copterdoc (Oct 9, 2005)

JOE PA said:


> Not sure why, but referring to it that way actually makes more logical sense that what everyone else uses......


 It doesn't to me.

When checking the synchronization of the cams, the one that hits the stop first, is "ahead" of the other. So, to solve the problem, you need to either [email protected] the one that hits first, or advance the other, to hit the stop at the same time.


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## Outback Man (Nov 21, 2009)

copterdoc said:


> It doesn't to me.
> 
> When checking the synchronization of the cams, the one that hits the stop first, is "ahead" of the other. So, to solve the problem, you need to either [email protected] the one that hits first, or advance the other, to hit the stop at the same time.


Everytime (which really isn't that often) I do something w/an Elite I do it backwards to start with...No idea why...


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## Maybee-R (May 15, 2006)

peregrine82 said:


> This has probably already been addressed. Why is Elite's advancing the cam terminology directly opposite to what everyone uses. They may not be the only one doing this but it can get confusing.


Its based off the end results. You [email protected] the cam your shorting its end. you advance you lengthen it. Its also they way I was told by their designer at the time.
From brace you draw the bow can be looked at as advancing the cams but if it were set half drawn already it would be [email protected] this is an age old argument for a lot of people. I think they chose a position and stuck with it.


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## Maybee-R (May 15, 2006)

Another thought is advanced from rest would be confused from full draw. I see where its confusing though. advancing the top cam to hit first compared to advancing the top cam for more draw length.


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## copterdoc (Oct 9, 2005)

Maybee-R said:


> Its based off the end results. You [email protected] the cam your shorting its end...


 That's the problem. 

Changing the cam's position, by changing the length of the string, in relation to the to the length of the cable(s), does not change the position of the cam when it is stopped, by the stop.

The only way to change where the cam stops at full draw, is by moving the stop, or moving what the stop contacts against.


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## Maybee-R (May 15, 2006)

copterdoc said:


> That's the problem.
> 
> Changing the cam's position, by changing the length of the string, in relation to the to the length of the cable(s), does not change the position of the cam when it is stopped, by the stop.
> 
> The only way to change where the cam stops at full draw, is by moving the stop, or moving what the stop contacts against.


Agree to a point. But advance to me is to gain and [email protected] would be restrict or loss. so in short if you lengthen draw length you advanced something some how. And Im not saying one way is correct over the other. it would be nice if everyone was on the same page though.


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## copterdoc (Oct 9, 2005)

Maybee-R said:


> Advance to me is to gain and [email protected] would be restrict or loss....


 Advancing, and [email protected], are adjustments related to time, not distance.

They change when something happens, not where.


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## peregrine82 (Aug 25, 2007)

Copter Doc and Rick, your posts are somewhat making my point for me. I know the relationship of cables and string to cam orientation. I just would like to see the descriptions of cam movement standardized.


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## copterdoc (Oct 9, 2005)

peregrine82 said:


> Copter Doc and Rick, your posts are somewhat making my point for me. I know the relationship of cables and string to cam orientation. I just would like to see the descriptions of cam movement standardized.


 I agree. You certainly have a point.


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## Maybee-R (May 15, 2006)

copterdoc said:


> Advancing, and [email protected], are adjustments related to time, not distance.
> 
> They change when something happens, not where.


But end results are what the tune charts are based off of. Not saying its right just what they built the Elite charts from.
draw lengths being the part your advancing or [email protected] 
Your way makes sense to me also and others have argued this point with me before. I agree timing should be the measurement, not the distance of draw length. after all its timing we are trying to advance or restrict.


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## Bearlee (Dec 24, 2009)

I have a very basic question, but one that is perplexing me. On my 2011 Hoyt Carbon Element with the fuel cams, my top cam stop has a rubber cushion attached the metal to prevent cable wear. This rubber cushion is spongy and compresses when it comes to full draw. This slightly bends the cable before the metal touches the cable. When properly timing the cam should the rubber cushion be considered the stopping point of first contact or should it be ignored and pulled into the wall where the metal stops on the cable? If the rubber is considered, my top "metal thingy" hits first, if not then my bottom "metal thingy" hits first.

Thanks for your thoughts.


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## Boogels (Jan 4, 2008)

Bearlee said:


> I have a very basic question, but one that is perplexing me. On my 2011 Hoyt Carbon Element with the fuel cams, my top cam stop has a rubber cushion attached the metal to prevent cable wear. This rubber cushion is spongy and compresses when it comes to full draw. This slightly bends the cable before the metal touches the cable. When properly timing the cam should the rubber cushion be considered the stopping point of first contact or should it be ignored and pulled into the wall where the metal stops on the cable? If the rubber is considered, my top "metal thingy" hits first, if not then my bottom "metal thingy" hits first.
> 
> Thanks for your thoughts.


Doesnt matter. Sync the cams as you like them best.

I found that if the top one touch all the way to the metal then I have a spongy back wall. Bottom one touching first then I have a more solid wall.

Also I shoot with the bottom one touching first and the top one's rubber just touching because then it feels my bow draw back straight as appose to the top touching first then my bow feels like it want to "lift" when aiming and I make poorr shots that way


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## WVaBuckHunter (Sep 30, 2010)

I know Baldy is busy, but I was/am looking forward to seeing him come back to this thread to "play".


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## huntnhammer (Nov 4, 2005)

Threads like this are why I come on here. Thank you for the info.


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## Bearlee (Dec 24, 2009)

Bearlee said:


> I have a very basic question, but one that is perplexing me. On my 2011 Hoyt Carbon Element with the fuel cams, my top cam stop has a rubber cushion attached the metal to prevent cable wear. This rubber cushion is spongy and compresses when it comes to full draw. This slightly bends the cable before the metal touches the cable. When properly timing the cam should the rubber cushion be considered the stopping point of first contact or should it be ignored and pulled into the wall where the metal stops on the cable?


Thanks Boogels and 
I had one person tell me to tear off the rubber part, any other opinions?


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## Outback Man (Nov 21, 2009)

Bearlee said:


> Thanks Boogels and
> I had one person tell me to tear off the rubber part, any other opinions?


I actually had somone tell me the same thing the other day...first time I ever heard that...figured if tearing it out was better it wouldn't be there in the first place...


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## Guardian Shoote (Jan 11, 2007)

ttt


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## IrishMike (Mar 19, 2007)

subscribed, great thread. 

Nuts and Bolts, Any advice or testing on Hoyt Fuel Cams? 

I have found that when your timing is perfect along with ATA and Brace your top cam will hit the stop first with about a 1/16 gap at the bottom in synch position. This seems to be the best performing position for this cam type. I have also found having the bottom cam 3/16 out of synch at full draw performs very nicely also when group tuning. 

Any thoughts or testing here?


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## Alpha Burnt (Sep 12, 2005)

Bump, breathe some more life back into this thread


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## Alpha Burnt (Sep 12, 2005)

ttt


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## B0hunt3r39 (Mar 13, 2003)

baldyhunter said:


> ..............it's not at all what you think it is LOL.
> 
> 
> 
> ...


I don't consider this a rant, just trying to get people to understand something! Thanks for the information, I have always understood the purpose of the stops and the position of the cams in the draw cycle etc. but never really got into it with any of my bows, I let the shops handle it, with this new vector 32 I just bought I'm really getting into it and I want to understand it better to get the best out of the bow! Thanks again


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## Peteyur (Jan 31, 2011)

I have to post here so that I can find it again. I will be reading and rereading this for years to come probably. I am a slow learner.LOL
Thanks to all that have posted the great info.

Pete


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## Macker (Mar 22, 2007)

great stuff!


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## ToddM (May 30, 2003)

That's a great point I always mix the two up as well. I think most guys, myself included in the past, only thought of how the cams came into the cables or how the stops hit together when "timing" a bow. I honestly didn't start thinking about the starting cam rotation until I bought my first solo cam and started reading about the solo cam having an "ideal" starting cam position. 

Maybe we need a sticky thread that would compile as many pictures of bow cams as we can find with their ideal starting positions and reference points to use. 

As an aside would that mean with the old original cam 1/2 cams that had the two lines to indicate "timing" at rest with the cables that when you tune a cam 1/2 you should strive to make adjustments that center the cables in those lines, and then mess try to adjust for the stop/groove coming into the cables at the same time? I know typically when I've followed Javi's old cam 1/2 tuning post that my cables on those cam reference lines are always within the lines, usually close to the same but never exactly the same. Would there be an advantage in trying to get them exactly the same in reference to those lines and is that even possible while still maintaining the cam stop/groove hitting the same time at full draw to maintain the wall?


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## nuts&bolts (Mar 25, 2005)

ToddM said:


> That's a great point I always mix the two up as well. I think most guys, myself included in the past, only thought of how the cams came into the cables or how the stops hit together when "timing" a bow. I honestly didn't start thinking about the starting cam rotation until I bought my first solo cam and started reading about the solo cam having an "ideal" starting cam position.
> 
> Maybe we need a sticky thread that would compile as many pictures of bow cams as we can find with their ideal starting positions and reference points to use.
> 
> As an aside would that mean with the old original cam 1/2 cams that had the two lines to indicate "timing" at rest with the cables that when you tune a cam 1/2 you should strive to make adjustments that center the cables in those lines, and then mess try to adjust for the stop/groove coming into the cables at the same time? I know typically when I've followed Javi's old cam 1/2 tuning post that my cables on those cam reference lines are always within the lines, usually close to the same but never exactly the same. Would there be an advantage in trying to get them exactly the same in reference to those lines and is that even possible while still maintaining the cam stop/groove hitting the same time at full draw to maintain the wall?


Hello ToddM:

A hybrid cam system is a 3 piece rigging system.

a) bowstring

b) buss cable (cable with 3 end loops)

c) control cable (cable with only 2 end loops).


When you understand how these 3 pieces work together,
you will no longer need to worry about timing dots, timing slashes/marks/lines, etc.


So,
a little history.


FIRST, came the single cam system,
with 2 pieces to the rigging system.

a) SUPER DUPER long bowstring

b) buss cable.


SECOND, came the hybrid cam system.


The SUPER DUPER long bowstring got cut into two pieces.

FRONT half of the SUPER DUPER long bowstring, is now the shorter bowstring on the hybrid cam system.
BACK half of the SUPER DUPER long bowstring, is now the "control cable" on the hybrid cam system.


So,
why is this important?


Cuz,
ultimately,
what we want is LEVEL nock travel.

If we have LEVEL nock travel,
then we have the cam rotation position in the correct spot.

GOOD arrow flight.
TIGHT fletched arrow groups.

That is what the cam designer is aiming for.


So,
if the timing dots are faded..
so, if the cam system USED to have timing slashes / lines....and no longer has these reference marks...
no biggie.


So,
I just finished tuning up a hybrid cam bow for flopduster.

Bowstring.
Control Cable.
Buss cable.


*WHAT HAPPENS WHEN YOU UNTWIST THE CONTROL CABLE?*

As you lengthen the control cable longer and longer, by removing twists,
the TOP CAM draw stop will move CLOSER to the cable, when at full draw.

If you pull your hybrid cam bow to full draw,
and you see a GAP between the TOP CAM draw stop and the cable,
when you LENGTHEN / UNTWIST the control cable,
the GAP GETS SMALLER.


*WHAT HAPPENS WHEN YOU ADD TWISTS TO THE CONTROL CABLE?*

As you shorten the control cable, by ADDING twists,
the TOP CAM draw stop will move AWAY from the cable, when at full draw.

If you pull your hybrid cam bow to full draw,
and you see a GAP between the TOP CAM draw stop and the cable,
when you SHORTEN / ADD TWISTS to the control cable,
the GAP GETS LARGER.



So,
now the buss cable.

We all know that the buss cable is what controls the MAX draw weight.

If we have the limb bolts maxed out,
and the limb sticker says the bow is a 60 lb bow,
and
we are only getting 58 lbs of draw weight...

we know that we add a few twists to SHORTEN the buss cable
and
we will soon be getting factory spec on the draw weight,
and the bow will deliver 60 lbs of draw weight,
when the buss cable has enough extra twists,
if the bow was a little low on draw weight.

TWEAK twists in the buss cable to hit factory spec for draw weight.

If the MAX draw weight is a skosh low, ADD twists to the buss cable.
If the AMX draw weight is a skosh high, REMOVE twists in the buss cable.


*NOW, WHAT ABOUT CAM SYNC AND THE BUSS CABLE?*


You also tweak the buss cable to adjust cam sync (top cam rotation position at full draw).

As you shorten the BUSS cable, by ADDING twists,
the TOP CAM draw stop will move TOWARDS the cable, when at full draw.

If you pull your hybrid cam bow to full draw,
and you see a GAP between the TOP CAM draw stop and the cable,
when you SHORTEN / ADD TWISTS to the BUSS cable,
the GAP GETS SMALLER.


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## nuts&bolts (Mar 25, 2005)

ToddM said:


> That's a great point I always mix the two up as well. I think most guys, myself included in the past, only thought of how the cams came into the cables or how the stops hit together when "timing" a bow. I honestly didn't start thinking about the starting cam rotation until I bought my first solo cam and started reading about the solo cam having an "ideal" starting cam position.
> 
> Maybe we need a sticky thread that would compile as many pictures of bow cams as we can find with their ideal starting positions and reference points to use.
> 
> As an aside would that mean with the old original cam 1/2 cams that had the two lines to indicate "timing" at rest with the cables that when you tune a cam 1/2 you should strive to make adjustments that center the cables in those lines, and then mess try to adjust for the stop/groove coming into the cables at the same time? I know typically when I've followed Javi's old cam 1/2 tuning post that my cables on those cam reference lines are always within the lines, usually close to the same but never exactly the same. Would there be an advantage in trying to get them exactly the same in reference to those lines and is that even possible while still maintaining the cam stop/groove hitting the same time at full draw to maintain the wall?


So,
at least for the Hoyt Cam.5 system:


a) tweak the buss cable to get max draw weight at factory spec.
....ATA should be close to factory spec.

b) tweak the control cable twists, so that the top cam draw stop and the bottom cam draw stop hit the cables at the SAME TIME
....this is a good, and easy to find starting point.

c) if you have a draw board, check for draw length
...draw length might be to spec
...draw length might be a little long
...if the bow is working for you (you can hold steady) then, leave the string twists alone

d) now go and creep tune your bow at 20 yards
....you will be tweaking the buss or control cable (your choice) to adjust the cam rotation position to find the sweet spot
....the sweet spot for cam rotation, will give you the smallest vertical spread in your arrow groups, when aiming at the top edge of a long piece of horizontal duct tape
....if NORMAL pressure into the wall of your bow has your arrows missing the top of the duct tape by 2 inches HIGH
....IF HARDER than normal pulling pressure into the wall of your bow has your arrows missing the top of the duct tape by 6 inches HIGH
....THEN, you have a 4-INCH vertical spread, when creep tuning your bow.

....sooooo, pick a cable, and tweak the twists....I like to use the control cable and try REMOVING a full twist
....if the NORMAL pulling into the wall arrows, and if the HARDER into the wall arrows are now only 1-INCH apart vertically.....we are going in the CORRECT direction for twists.

....keep tweaking the twists until you get ALL your arrows the SAME height above the top edge of the duct tape.


This way,
you don't need the reference marks or timing dots.

Just CREEP tune your hybrid cam bow,
to find the sweet spot for your cam rotation position (cam sync).


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## spswihart (Dec 21, 2009)

N&B,,, Great info here, but my head is starting to spin. I am a shooter, not a thech, and I am trying desperately to improve. I have been working on my form and shot sequence. Found that my DL was too short. I shoot a Mathews DXT, so I had a new cam put on and have the DL perfect (I think), the pin does not move much at all. After reading most of this thread, I looked at my new cam and the little holes on the bottom metal thingy don’t line up with the string. An arrow lined up with the holes angles slightly towards the string. Not much but enough to be obvious. I guess my question is “what are the ill effects of this type of a cam starting rotation location”? My (stock) bow string is already twisted up pretty tight to get the DL right. If I twist the cable (either way) to change the cam starting location, it will change my DL, and I need to be able to get back to where the DL is now. Do I need to twist of untwist the cable to re*ard the cam? Do I need to twist or untwist the string to make up for the cable? And is it worth it to change the rotation location at all? I am a Biologist, and these things are hard for me.


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## HC Archery (Dec 16, 2004)

Great thread.

What I have seen with various Mfg.... a lack of good basic dealer info on timing, etc. their systems. And it should be KISS method big time.


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## ToddM (May 30, 2003)

Great info N&B! 

Would the spiral x cams be tuned the same way, aside for the lack of a cam module and the let off adjustment?


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## frd567 (Jan 30, 2012)

ttt


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## safarisports (Nov 10, 2010)

tagged for later


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## 138104 (May 14, 2009)

Ok, my head hurts. I am messing with an Elite GT500. Peak weight is hitting later in the draw cycle than it should be and draw length is long. I started untwisting the cables to reterd the cams so it hit peak weight earliet. Now, I am reading baldy's post and he said twist the cables to reterd the cams. Ugh...so I guess I need to undo my changes and put twists in my cables?


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## Putt4Doe (Sep 2, 2009)

[emoji1303][emoji1303]


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## archer58 in pa (Jan 3, 2007)

Perry24 said:


> Ok, my head hurts. I am messing with an Elite GT500. Peak weight is hitting later in the draw cycle than it should be and draw length is long. I started untwisting the cables to reterd the cams so it hit peak weight earliet. Now, I am reading baldy's post and he said twist the cables to reterd the cams. Ugh...so I guess I need to undo my changes and put twists in my cables?


You are making the correct adjustments. Untwist the cables and add twists to the string at the same time. By doing both you'll maintain ATA also.
The DL coming in long will result in a peak later in the DFC.
You were correct,,,untwist cables and twist string to move peak earlier.
On the GT500 you should hit peak weight at about 6 1/2" to 7" into the draw.


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## Thatha1 (Mar 23, 2016)

as a novice this is new information ... thanks...


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