# Bareshaft tuning a binary cam bow



## jim p (Oct 29, 2003)

I have a pearson advantage that I can not get to bare shaft tune. I have several other pearson bows that bare shaft tune great but they are not binary cam bows.

I have very carefully moved the rest in small movements to the left and the right. No matter how I move the rest the bare shaft keeps hitting 8" left of the fletched arrow. The bow is set at 50 lbs and 28" draw and I am shooting victory hv1 400 arrows with 100 grain tips.

When holding the bow there seems to be a slight lean of both limbs to the left of maybe 1/8". It is a right handed bow. 

If anyone has any suggestions on how to get the bow to bare shaft tune other and torquing my grip let me know.

This bow is probably only going to be used for target shooting so I am thinking that I need to walkback tune and then group tune and let that be the end of the tuning.

One thought that I have is that the draw length might could be varied to get the bare shafts to hit with the fletched arrows. What do you think? Would a bare shaft hitting left of fletched arrow indicate that the draw length might be too short?


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## enewman (Jun 5, 2007)

This is just some thoughts. Center the rest. Level knock. Make sure cams are in sync. Make sure bow is not to long of a draw. Draw a line vertical on target. Stand 2 to 3 ft from target. Shoot the bare shaft at line. Adjust sight till on line then back up 10 yards and shoot. Then repost what arrow is doing. Shoot at least 3 arrows at a time. See if all on left side. Or all right side or if they split the string. Remember. Bow needs to be set up correct and form needs to be good. Or stop shooting bare shafts. Or you will be bald from the hair pulling.


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## Huntinsker (Feb 9, 2012)

When nothing you do to the bow makes a change, you need to look at yourself. I'd bet that you have a little too much pressure on the left side of your grip.


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## SonnyThomas (Sep 10, 2006)

Beat myself to death earlier this year trying to get my Pearson MarXman to bare shaft - Legend cams. See pic - best I could get. Pictures not in order, but check where the fletched arrows are and the bare shaft - both trying real hard to go back in the same holes.

Moved rest, tried paper tuning, tried different grip pressure, yelled, even cussed. Didn't help a bit. Went back to French tuning. Won 3D that weekend. Placed and won 6 times at club 3Ds and in ASA Qualifiers, 1st and 2nd and at the State Championship I placed 3rd. 
I don't see how you can go wrong with French tuning except add playing with the rest height or nock position to see if groups can be tightened up. 


No yokes, we can't correct cam lean. Timing tab on the Legend cams are so out in the open you can use a feeler gage to set timing. I used a piece of cellophane off a pack of cigarettes. Had timing checked at a archery shop and he said he couldn't time it any better - like it was perfect... 

What year Advantage? Fixed draw length cams don't help. Interchangeable modules, $23.00 or $29 per set, but one set should be all you need.

If you have a good grip I think it's HS to change it. What, carry a log book for grip pressure for every bow you shoot?


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## b0w_bender (Apr 30, 2006)

If you read the Easton tuning guide it's pretty clear if you can't get the arrows to bare shaft then you need to look at arrow spine. They call it bow tuning but it's actually of matching the bow and arrow system as well as an adjustment exercise. You can adjust your bow all day long but if you are shooting 2 x 4's they won't fly well. You may want to look at the spine chart again I think 500's might be a better choice, but confirm from the manufacturers spine charts.

It could be a grip issue but usually that shows up as an inconsistency in accuracy with an occasional major left right hit and not consistent errors one way or the other. 

I've seen this kind of behavior caused by a single jawed release when a double jawed release shoots straight. You can get a single jawed release to work but because of the side to side oscillation in the release you need to have properly spined arrows. Having said that any left to right motion in your release will amplify a poorly spined arrow bow combination.

I think the binary cam concern is a red herring and not the cause of your issue.


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## Fury90flier (Jun 27, 2012)

put some 125 grain points (maybe 140grn) on there and see what that does to the bare shaft vs fletching relation....it will tell you the direction you need to go 

Sonny...can't the cam lean be resolved with shimming? I know this is what was done many years ago...if necessary.


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## jim p (Oct 29, 2003)

Sonny, I know what you mean. I have been tuning on this bow off and on for the last 4 years. I even sent the bow to Pearson for them to take a look. They said that the limbs may be leaning to the left just a small amount but that they did not see a way to correct this. The bow shoots fine just like yours so I am thinking that all I can do is walkback tune and group tune and let it go.

I have several other bows that shaft tune with no problem. 

I have shot hv1 400's and XXX 150 spine arrows with the same results so I don't think arrow spine will fix this problem. 

I am not a bow designer but I think that the grip is not lined up with the cams correctly. I don't know if the grip needs to be moved to the left or the right but I think that it needs to be moved. Maybe one day I will come up with a way to move the grip so the pressure can be applied at the correct spot.


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## jim p (Oct 29, 2003)

My advantage is a 2010 with legend cams. I have 3 or 4 sets of modules to make the draw length longer. I am currently using 2T0 and 2B0 modules on the bow. I can't remember if these are for 27.5" draw or not. I have them set up so that they are giving maximum draw length which gives the most letoff and most valley. I tried shooting other modules for longer draw lengths but there was no valley at all and I could never relax into the shot without the bow wanting to go forward.

Sonny I noticed that your bare shafts are hitting right and the tails are leaning to the left. Mine are just the opposite.

Which way would I need to torque my bow to make my bare shafts go right. If I can determine which direction that I need to torque the bow then maybe I can build up one side of the grip so that the bow is torqued automatically in the correct direction.


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## Fury90flier (Jun 27, 2012)

try changing how you pull at release. For me, that is easier to control than the grip. Just go by results based testing.

Or maybe changing DL a little could have a similar effect


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## jim p (Oct 29, 2003)

My result based testing is not good. I do have some 500 spine arrows that I will try per your suggestion of using a weaker spine.


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## jim p (Oct 29, 2003)

I have pulled different at release and used several types of releases with very little effect.


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## jim p (Oct 29, 2003)

I just got through doing some testing. I got back 10 yards and with my bare shaft, I twisted the bow clockwise and shot the arrow. The arrow almost hit on its side, tip way left and nock way right. So now I know that I need to twist the bow counter clockwise. I back up to 20 yards draw the bow and come to target. Now I twist the bow until the sights are 8" left of the target and then while holding the twist into the bow I twist at my waist bringing the sight back on target. I fire the bow and the arrow hit where the sight is located and the shaft goes into the target straight.

Now I do the twist and use a fletched arrow. The fletched arrow hits where the sight is pointing.

So now I know that the bow grip can be modified so that my grip will cause the bow to twist to the left. I need to come up with a way to add about a 3/8" wide strip on the right side of the grip on the bow. I may start out using some epoxy putty to make the grip.

So if anyone wants to try twisting their bow and seeing how the bare shaft reacts please do so and let me know what happens. Sonny I am thinking that you could twist your grip a little clockwise and get you bare shafts hitting good. You might even be able to get more hand into the grip and make your bow twist a little to the right.

If anyone has a good idea on how I can modify my grip for testing please let me know.


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## Fury90flier (Jun 27, 2012)

jim p said:


> My result based testing is not good. I do have some 500 spine arrows that I will try per your suggestion of using a weaker spine.


 Don't over think this...you can only tune to your abilities. If results based testing doesn't work for you...you're simply at the max tuning you can do for your skill level. Please don't take offense to this statement...just trying to keep you from chasing your tail.


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## jim p (Oct 29, 2003)

Too late, I have already chased my tail for 4 years. 

I have made a grip modification and as soon as I cool down from my grass cutting I am going to go out and see how it works.


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## enewman (Jun 5, 2007)

Before you start trying to change the pressure on your grip. Is the rest in the center. In knoc level. Go get you some 150 gn tips and some 125 tips. Pick a spot on target and shoot all three arrows. If all fly the same then it's you. If not it's the arrow/bow. I know that you can chage arrow flight by changeling your grip, but if your hand is relaxed and the bow is touching only the mussel pad next to your thumb, and if you was to open your hand up while at draw and your fingers are pointing out at a 45 degree I dont think you could be adding that much torque to the bow. There are just a few things to try before you start reshaping your grip


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## jim p (Oct 29, 2003)

Well I made my grip offset about 3/8" to the right. It didn't affect the bare shaft impact. 

The Advantage has a bow grip with a thumb hole. The grip looks sort of like a D and your hand goes on the left side of the D with your thumb going inside the D. I decided to reach all the way across the D with my thumb and this torqued the bow enough that the bare shaft hit with the fletched arrow.

I have taken my modified grip off and I may add another 1/2" offset to the grip and try it again.

I may have to approach this in another direction. Maybe I need to move the rest on the bow until the bare shaft is hitting where the sights are now aligned. If the bare shafts are hitting straight into the target at this point, then maybe I need to start reducing the size of the fletching until the fletched arrow hits with the bare shaft. I might end up with micro blazers or maybe something even smaller.

The rest is now in the center and the bow is walk back tuned. I am shooting with an open and relaxed bow hand.

I know that it is me causing the problem. I have a home made hooter shooter and I bet it can't get the bow to bare shaft tune either because it can't twist the bow counter clockwise.


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## enewman (Jun 5, 2007)

You should not have to twist the bow to shoot


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## jim p (Oct 29, 2003)

I agree.


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## enewman (Jun 5, 2007)

Go to texans bowhunter.com. Go to equipment tuning. Then look at bare shaft tuning info. You can see what I did with a bare shaft and never touching the bow after center shot and knoc was set


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## Fury90flier (Jun 27, 2012)

Jim...I would suggest that you seek a qualified coach or mentor to assist you here. The work you're doing with the grip seems unnecessary. I would hate for you to spend time on the path you're on unnecessarily.

If a coach or mentor is not available to you there are several people here that can help you via internet coaching...Nuts & Bolts comes to mind. I too can help but I'm not setup to do internet video coaching just yet. The best I could do is video capture, I review, make suggestions etc...but you really need hands on or streaming video for internet coaching to work.

if you can, get someone to take pictures of your shooting. You'd need to see grip clearly, anchor clearly, head to toe clearly, from behind the arrow at draw etc. With proper pics we could probably assist you to getting issues resolved.


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## jim p (Oct 29, 2003)

Thanks for all the help fellows. I have 4 other bows that bare shaft tune great. I think that this bow is like a car out of alignment and there are no tie rods to adjust. The binary system is either in alignment or it is not and there is no adjustments to be made that I can understand that would get things into alignment. Nuts and bolts has suggested that I twist up the cables a little to make the draw length longer. I know that he is very intelligent and knows his bows. My problem is that I have a hard time making a change to the bow unless I totally understand how it is going to affect the bow. I don't have a clue how making the draw length longer would bring the bow into tune. I have had draw length modules on the bow that made it an inch longer and that did not make it tune.

Again the bow shoots fine. It is irritating that it wont tune.


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## jim p (Oct 29, 2003)

I really like the Texas bowhunter site.


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## Fury90flier (Jun 27, 2012)

binaries are simple...actually much easier than any yoke bow. That assuming you have quality limbs. otherwise you need to shim....still not that difficult.

with a binary instead of pulling on a yoke, you need to understand dynamic spine...arrow tuning. Once you "get it"...tuning becomes much easier.

for some reason people thing "I want to shoot X arrow at X length with X point"...that simply doesn't work with a non yoke system.

shoot the arrow the bow likes with YOU as a flinger and all will work well.

get an assortment of different weight points...go back to bare tuning. All you're looking for is impact location---nock kick means nothing at this point....simple grip, how you release, follow through, DL will cause nock kick. I can really screw with someone by showing nock kick left, nock right, straight, up, down...all over the place....I won't do anything to the bow- just how I grip, just how I pull through.


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## enewman (Jun 5, 2007)

jim p said:


> I really like the Texas bowhunter site.


Me to. If you looked at what I did about bare shaft tuning. It's a little different. I don't post most of that on here. I'm would problely get bashed by the nuts and bolt fans. Don't get me wrong I think he is very good good at what he does and he has helped me to. I just got a deferent theory. On tuning. 

Just like the post above on his last paragraph. Tune the arrow to the bow. Not bow to arrow


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## SonnyThomas (Sep 10, 2006)

Fury90flier said:


> put some 125 grain points (maybe 140grn) on there and see what that does to the bare shaft vs fletching relation....it will tell you the direction you need to go
> 
> Sonny...can't the cam lean be resolved with shimming? I know this is what was done many years ago...if necessary.


Shimming won't help in this case.

55 and a hair more draw weight, depending on arrow, 284 fps and 294 fps. 400 spine arrow is the call. I tried 500 spine and there was so much whip hitting the target the 500 shaft snapped. Present 400 spine arrows have 80 gr glue-in points. I did try 100 gr glue-in points and virtually the same thing. I ain't driving myself nuts to bare shaft tune my bow. 



jim p said:


> Again the bow shoots fine. It is irritating that it wont tune.


If it shoots fine, it's tuned. That grip pressure wild hair thing is ontarget7's concept of getting a bow to bare shaft tune. Having a few bows set up to shoot I'm not carrying around a log book so to remember what grip pressure is needed for each one. Damned crazy is my opinion of needing different grip pressure to tune a bow. You go back and look and bare shaft tuning was a rarity here until ontarget7. Another opinion; ontarget7 has a "product to sell" (his tuning business) and he does "puff up" it good to sell. 

My hunting bow has a floating yoke. So no yoking tuning. I did French tune it and my fixed broadheads are pin point accurate out to my imposed limit of 40 yards. French tuned you may need to play with the rest height on nocking point to see if groups can be tightened up, if they need tightened. 
Lord! Think of needing grip pressure and then it gets cold and you have to wear gloves. You going to tune again?


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## Huntinsker (Feb 9, 2012)

I agree that you shouldn't have to twist a bow to be able to shoot it. However I'm a firm believe that not all bows will work with the same bow hand grip. The bows are designed differently, the grips are designed differently and it would be silly to assume that they will all be the same. Typically, unless a person has a problem with their grip to begin with, the pressure changes will be very small. Most people wouldn't even notice it. 

Just last night a gentleman came to me for help with his bow because 2 other shops couldn't help him to get it to paper tune. I'm not a fan of paper tuning but I helped him anyway. He said that no matter what they did to the bow, they could not eliminate a hard nock right tear so I set everything back to neutral so we could start over. I immediately told him that I bet I know the problem but I said I'd like to see you shoot first. My suspicions were confirmed when I saw that he shot with his knuckles parallel to the riser and his fingers stretched straight out. That hand position puts a large amount of pressure on the left side of the grip which will cause a hard nock right condition. 

We spent 10 minutes working on his grip and then set up some paper. His first 3 shots with the new (proper) grip there was a little nock right tear so I added a twist in his right yoke and took one out of his left. His next 3 shots were bullet holes. Just like that. He though I was magic haha. 

Moral of the story is that sometimes you can't tune a bow to a grip or form because the form is too far from neutral to begin with. That's why people generally agree that there is a standard "proper" form for beginners to try and use. This guy had been shooting and bow hunting for 20 years and never was told or never knew about the proper grip mechanics. He said that he always just moved his sights to his broadheads and went to the woods. This year he wanted to see if he could tune his bow and it took a little form work to get that done.

I guess I just don't think it's fair to say that suggesting that a little grip change is totally bogus especially when someone details that nothing else has helped. Sometimes the form we've been using for decades, isn't actually correct. I do agree however, that if you have a grip that's what would be considered "good", you should be able to tune the bow with no grip change. 

OP, I don't know if you've seen it yet but GRIV has a great Thing A Week about the grip. It's worth watching and he says some things that I don't think a lot of people think about. He mentions that you want you knuckles 45deg to the riser and your hand flat to the target. Another way to think of that, and what I told the guy last night, is that you want your knuckles to be 45deg to the riser and 90deg to the plane of the arrow. If I had to guess, I'd say that your pinky knuckle is pushed more towards your target than your index knuckle and that's what's causing the pressure on the left side of your grip. 

Here's the link. https://www.youtube.com/watch?v=R1p7mGdFNBE

Also, make sure you don't have excessive face pressure on the string. Sometimes that's over looked but it is a very real thing that can cause issues.


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## jim p (Oct 29, 2003)

Thanks for the video. As far as I can tell I am using the same or very similar techniques.

I have got to stop playing with this bow and do a little shooting now with my hunting bow so I can be on my game for deer on the 15th. 

Thanks for everyones help. I may take this up again at a later date. I also may make a set of cables for a split yoke and get longer axles and QCC's and see if I can turn a binary cam bow into a 2 cam. This way I should be able to tune it.


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## 60435 (Mar 20, 2012)

bare shaft tuning is a waste of time!! tuning should always be done with the configuration you are planning on using. use a good program like ontarget to start with get your arrows right on here first


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## Fury90flier (Jun 27, 2012)

It's only a waste of time to those that have very poor form or don't know what they're doing.


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## b0w_bender (Apr 30, 2006)

Fury90flier said:


> It's only a waste of time to those that have very poor form or don't know what they're doing.


what he said


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## Huntinsker (Feb 9, 2012)

Fury90flier said:


> It's only a waste of time to those that have very poor form or don't know what they're doing.


Haha.......perfect.


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## jim p (Oct 29, 2003)

I had a little time yesterday so I made up a dual cable rod system so that I could make a shoot thru system. I could not get the cables spread as wide as I wanted because the cables were hitting the side of the top cam. But with the cables spread the arrow hit into the target almost straight but still about 6" left. This is a 50% improvement in performance.

Now I am looking for a bottom legend cam with a 2B0 module. If you know where I can find one of these cams let me know. 

If I can open up the shoot thru I think that the bare shaft will shoot correctly.


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## Fury90flier (Jun 27, 2012)

put a cable spreader between the buss and control cables....basically a section of arrow with nocks on the ends....will help keep the cable from hitting the cam.

do some looking on here and you can find what I'm talking about.


take the stabs off (assuming you have them):

go warm up, say 2-4 ends.

now make each shot count for the next few ends
At the shot- does the bow wiggle L/R If so...tuning isn't going to fix the problem-- well, tuning the bow won't but tuning YOU will.

If you're getting that L/R swing of the bow at the shot...work on
Bow hand placement--so easy to have the center of pressure of the bow a couple mm left or right...got to play with wrist position---check out the nuts & bolts of archery for tips on getting centered on the riser.

pulling straight through the shot- most people think they have this right and so many are pulling off to the side-- kicking the tail of the arrow out. Practice getting that elbow to go straight back in-line with the arrow. 

While playing with grip and how you pull through pay close attention to bare shaft location and nock kick. You may find that a simple modification to your form clears up the issue.


anyone got a cheap video camera they can donate...I'll made some vids where all I do is change 1 thing on my form and completely change nock kick...maybe impact location if I do that 1 thing bad enough.


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## Fury90flier (Jun 27, 2012)

Oh, almost forgot. On the cable spreader...you'll want to put a couple nocks (tie in or standard) on the cables so the spreader doesn't slip.


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## jim p (Oct 29, 2003)

Ok. I had another idea today. I decided to check the cam lean on the bows that I have that will bare shaft tune and compare the lean to the bow that wont bare shaft tune.

The bows that bare shaft tune: When an arrow is placed on the right side of the cam the sidd of the arrow is about 1/4" to the right of the nocking point on the string. One bow is a single cam and the cam leans so that the arrow is 1/4" right of the nocking point and the idler wheel is straight down the string with no lean. The other bow is a hybrid cam system and both cams lean so that the arrow is 1/4" right of the nocking point.

Now the bow that wont bare shaft tune:
Both cams lean so that the side of the arrow is 1/2" to the right of the nocking point. This is twice to 3 times as much lean as the bows that will tune.

Today I took the bow apart and there was a tiny bit of slop in the limb pockets so I twisted the limb pockets as far as I could as I assembled the bow. Now the bow is shooting 12" right of where it was shooting before but the bare shafts are still hitting 8" or more to the left.

My next attempt may be to take the bow apart and see if I can file down the shoulder of the cam bushing on the right side. I am hoping that this will decrease some of the cam lean. 

Does anyone know what the standard thickness are for the various cam shims. I only want to remove enough shoulder to match the various thickness of cam shims.-----


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