# tuning and plunger tension question



## Greysides (Jun 10, 2009)

I reckon you've two choices:

1. Do nothing, you're close enough. For a RH archer, BS impacting just right of the fletched is spot on for basic tuning.

2. Decrease the poundage of your bow slightly and recheck.


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## alaz (Mar 8, 2009)

Greysides said:


> I reckon you've two choices:
> 
> 1. Do nothing, you're close enough. For a RH archer, BS impacting just right of the fletched is spot on for basic tuning.
> 
> 2. Decrease the poundage of your bow slightly and recheck.


I had thought that bare shafts hitting right of fletched indicates stiff spine, so I would need more poundage?


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## Greysides (Jun 10, 2009)

alaz said:


> I had thought that bare shafts hitting right of fletched indicates stiff spine, so I would need more poundage?


Only if you're holding the bow in your right hand i.e. are shooting left-handed, in which case you would.

Fletching stiffens an arrow so BS impacting just to the right of the fletched arrows is usually the desired starting point for further tuning.


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## alaz (Mar 8, 2009)

Greysides said:


> Only if you're holding the bow in your right hand i.e. are shooting left-handed, in which case you would.
> 
> Fletching stiffens an arrow so BS impacting just to the right of the fletched arrows is usually the desired starting point for further tuning.


OK...so I am completely embarrassed...
I need to get my left and rigth straightened out

My BS was to the left... I do not know what I was thinking when I was typing!

Would decreasing plunger tension help in that case?


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## Greysides (Jun 10, 2009)

Okay. 

There will be more experienced people that may chime in but.... IMO...

If increasing poundage is an option it would be the best and easiest choice (reset BH and NH to current values).

If not, you could try decreasing the spring tension. You are very close and it may work.

Another, again less-preferred option for me, would be to increase your BH slightly.

With any of these things, note what changes you've made so you can retreat should things get worse and not better.


If you are shooting good groups perhaps you should continue as you are for a while. The next stage of tuning would be to tweak all factors a little at a time over a period of time and note the results.

Some people may well find that the best tune for them after all of that is a ..... stiff arrow....


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## alaz (Mar 8, 2009)

Thanks for your patience!
I will tinker with my plunger tension and see how that changes groups and tune.




Greysides said:


> Okay.
> 
> There will be more experienced people that may chime in but.... IMO...
> 
> ...


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## dchan (Jun 29, 2004)

Left bare shaft is stiff for right handed shooter.
1"-2" at 25 yds for most is hardly worth worrying about. Especially for an intermediate-advanced shooter. If you must, try less pressure but something to consider. Slightly stiff shafts will be a little more forgiving than slightly weak shafts.


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## Viper1 (Aug 21, 2003)

a -

You're a right handed shooter? 
A LEFT BS *+* a tail right kickout = a stiff arrow.
IF either is missing and your target is non-directional, something else is going on.

You can:
Turn in the limb bolts (increasing weight/pre-load)
Weaken the plunger spring
Move the plunger in towards the riser
Raise the brace height

Based on your description and assuming your bow has a "textbook" set up, I would turn in the limb bolts or slightly weaken the plunger spring.

After that, you'll need to do some form of walk-back tuning to determine the optimal combination of the above.
Walk back tuning can be used to determine plunger position and tension, but once you do that, you may need to compensate with the other parameters.

Viper1 out.


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## alaz (Mar 8, 2009)

I appreciate the help:
I have a tail right kick (shot bare shaft thru paper, plus I can see how it sticks in the target compared to fletch) and left BS
Based on my options, I will weaken the plunger spring.

I do not think this will make a tremendous difference in my shooting, but I am trying to learn more about tuning.

Is there a downside to softening the plunger tension?





Viper1 said:


> a -
> 
> You're a right handed shooter?
> A LEFT BS *+* a tail right kickout = a stiff arrow.
> ...


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## Viper1 (Aug 21, 2003)

a - 

Not really, but like anything else, it can be taken too far. 
By weakening the spring, it effectively brings the arrow closer to center on launch. 
However, since you're not that far off, the amount of weakening required will be pretty small.
Assuming "medium" stiffness, I'd start with 1/2 turn and work from there. 

Like dchan said, you may not want to bother. 
Your call.

Depending on the level of the shooter, if the correction takes more than a few minutes to accomplish, it's usually not worth it. 

Viper1 out.


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## alaz (Mar 8, 2009)

Thank you. That is very helpful. Good to know that I am not too far off as well.



Viper1 said:


> a -
> 
> Not really, but like anything else, it can be taken too far.
> By weakening the spring, it effectively brings the arrow closer to center on launch.
> ...


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## lksseven (Mar 21, 2010)

Alaz,

I think if your bare shafts are 'nock right' into the target, that your arrow dynamic spine is a bit stiff. My tuning experience is that plunger tension will walk bare shafts across the face of the target, but it won't really solve a stiffness problem resulting in a 'nock right' target entry. To fix that, try increasing your brace height 1/4 - 1/2" and test. If that doesn't fix it, then increase your draw weight a little bit and test.

Listen to Viper - you'll need to do a walk back test. One of the things you want to see in a walk back is if the arrows are entering the target perpendicular to the face _(you can use tension adjustment to walk the bare shafts into the fletched group at a given distance, but if the dynamic spine is too stiff, then at a different distance the arrows will diverge again. If the arrows are perpendicular into the target face at different shooting distances, that's a good indicator that the dynamic spine is 'on', and the arrows are coming straight out of the bow_.


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## alaz (Mar 8, 2009)

lksseven said:


> Alaz,
> 
> I think if your bare shafts are 'nock right' into the target, that your arrow dynamic spine is a bit stiff. My tuning experience is that plunger tension will walk bare shafts across the face of the target, but it won't really solve a stiffness problem resulting in a 'nock right' target entry. To fix that, try increasing your brace height 1/4 - 1/2" and test. If that doesn't fix it, then increase your draw weight a little bit and test.
> 
> Listen to Viper - you'll need to do a walk back test. One of the things you want to see in a walk back is if the arrows are entering the target perpendicular to the face _(you can use tension adjustment to walk the bare shafts into the fletched group at a given distance, but if the dynamic spine is too stiff, then at a different distance the arrows will diverge again. If the arrows are perpendicular into the target face at different shooting distances, that's a good indicator that the dynamic spine is 'on', and the arrows are coming straight out of the bow_.


They enter straight with the fletched (as far as I can tell), they enter tail right with BS.

I am at 600spine now. How much difference is 650? Carbon Express charts say my arrow would be weak with that spine, same specs. I am maxed out on my poundage. While I think 2 more pounds would be ideal, just not ready to move up in poundage again. As you had mentioned before...I would like to fit the arrows to the set up.


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## lksseven (Mar 21, 2010)

alaz said:


> They enter straight with the fletched (as far as I can tell), they enter tail right with BS.
> 
> I am at 600spine now. How much difference is 650? Carbon Express charts say my arrow would be weak with that spine, same specs. I am maxed out on my poundage. While I think 2 more pounds would be ideal, just not ready to move up in poundage again. As you had mentioned before...I would like to fit the arrows to the set up.


Yes, I agree about making the arrows be the tail, not the dog (if you have the $$ and the patience). 

So, if increasing draw weight is 'out', then try increasing brace height. Don't be afraid to keep increasing it and then testing, until you get the bare shafts nesting with fletched, and 'nock neutral' in the target face. That maybe be 1/4", 1/2", 1", ?? (don't go too crazy with it, but you'll learn a lot in the process - it's not a tatoo, you can always change the BH at your pleasure). If changing the BH "gets you there", then you'll have to test and determine if getting the bare shafts tuned has impacted your overall tune/forgiveness (does the new tune allow higher scores? same scores? lower scores?). Also, a significantly higher BH will lower your arrow speed - probably not enough to make any real-world difference at indoor distances, but outdoor distances might require more decisions to be made in the Spring.


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## chrstphr (Nov 23, 2005)

i dont understand why anyone would recommend adjusting the plunger. While this may be a slight fix at the 25 yards you are shooting, as soon as you shoot further back or nearer, the bareshafts will not hit with the fletched, and the fletched will not hit straight because you have adjusted the plunger weaker and now the arrows will go in the weak direction. 


The plunger is not used to adjust spine of arrow. Bow poundage is used ( adjusting the limb bolts).. 


Of course is you are only ever going to shoot 25 yards, then adjust away. Tuning for one specific distance, you can adjust several things wrongly to get the desired groupings including adjusting centershot, arrow rest, nock height, brace height etc. 


Chris


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## alaz (Mar 8, 2009)

Does anyone have an idea on how many turns in I could turn a AL1 riser limb bolts from factory setting?
Is there a standard?
Also, is there a "good" tiller measurement?
thanks.


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## chrstphr (Nov 23, 2005)

you can turn in a limb bolt until it bottoms out. Of course you need to loosed and back out the rear smaller bolt in the back so the limb bolt can continue in. 

If factory setting is in the middle of the limb pocket, then you should have 4 turns or so. 



regarding tiller, even tiller is a good place to start, while even to 3/8s positive is normal. Tiller will depend on how you grip the bow and how you finger grip the string. All you want is for the bow not to rise up or move down during draw and anchor. You want the bow to float level while you draw and anchor. Whatever tiller gets you there is fine. I have shot bows with 1 inch positive tiller and 1 inch negative tiller with no effect on groupings or how the bow shot. Currently i happen to shoot one quarter positive tiller.


Chris


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## alaz (Mar 8, 2009)

Thank you.
When you say positive tiller...what is the positive in reference to...top limb?



chrstphr said:


> you can turn in a limb bolt until it bottoms out. Of course you need to loosed and back out the rear smaller bolt in the back so the limb bolt can continue in.
> 
> If factory setting is in the middle of the limb pocket, then you should have 4 turns or so.
> 
> ...


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## horndog (Jan 5, 2009)

Get your self a cheap chrono and a copy of Archer's Advantage. Not an easy program to learn but well wroth it!

I use an F1 chrony


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## dchan (Jun 29, 2004)

chrstphr said:


> i dont understand why anyone would recommend adjusting the plunger. While this may be a slight fix at the 25 yards you are shooting, as soon as you shoot further back or nearer, the bareshafts will not hit with the fletched, and the fletched will not hit straight because you have adjusted the plunger weaker and now the arrows will go in the weak direction.
> 
> 
> The plunger is not used to adjust spine of arrow. Bow poundage is used ( adjusting the limb bolts)..
> ...


I agree the best way is to modify weight to get the closest spine match but I have to dis-agree that plunger pressure doesn't play a part in the adjustment for spine. 

You do need to do walk backs and check at several distances however how much a plunger gives as you release the arrow (plunger tension) will affect your dynamic spine and plays a part in adjusting for dynamic spine. 

As Viper mentions you can go too far. If the plunger is too soft, you can bottom it out upon release and you will get false readings.


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## alaz (Mar 8, 2009)

horndog said:


> Get your self a cheap chrono and a copy of Archer's Advantage. Not an easy program to learn but well wroth it!
> 
> I use an F1 chrony


I am looking for a good program for recurve. I will check it out.
How are you using the chrono?


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## horndog (Jan 5, 2009)

alaz said:


> I am looking for a good program for recurve. I will check it out.
> *How are you using the chrono*?


The chrono determines the total horse power your bow is producing in feet per second. The program translates that to output dynamic spine.


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## alaz (Mar 8, 2009)

Just got a chance to shoot some today after putting a few turns into my limbs.
Bare Shaft and Fletched Shafts hitting in the same spot (or as close as I can put them...no real discernible difference in flight between the 2) at 25yds.
I just assumed the bow comes bottomed out from the factory like most compounds. 
I will use the plunger to fine tune from here (based on all the info.)

The bow is a little louder, little stiffer through the clicker, but I just need to get used to the change.
Thanks guys for the help!


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## bobnikon (Jun 10, 2012)

I have always been of the opinion, if you have the time, that you should mess with everything. Take note of your current settings and then go to town. Change one thing at a time, first increase and then decrease and note the changes. Return to baseline and then try a different variable. Keep repeating until you know how each thing affects *your *bow with *you *shooting it. Then if you still have time start combining variables. Try and figure out from your experiments with single variables what combining them will do, and then see if you were right. It behooves us to understand our bows and to be able to fix things when something is off. If one day you notice an inconsistency, then you know a variable that will affect it and you can do something about it. The key is knowing how to get back to baseline when you go too far out of spec. That is why you should document every current stat, and then each change and its effect. Heck you may discover a set of settings that work better than what you are currently using. It isn't rocket surgery, but it can be really satisfying as compared to adjusting settings because someone suggested it.
Just my $0.02


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## chrstphr (Nov 23, 2005)

dchan said:


> I agree the best way is to modify weight to get the closest spine match but I have to dis-agree that plunger pressure doesn't play a part in the adjustment for spine.
> 
> You do need to do walk backs and check at several distances however how much a plunger gives as you release the arrow (plunger tension) will affect your dynamic spine and plays a part in adjusting for dynamic spine.
> 
> As Viper mentions you can go too far. If the plunger is too soft, you can bottom it out upon release and you will get false readings.


 The plunger is used to adjust for different minute releases and make the majority of the releases consistent. A bow can be tuned to shoot a group with a rock hard plunger or with no plunger at all. Adjusting plunger for walkback tuning from 50 meters to 5 is done to adjust how the arrow is flying straight out of the bow based on the average of your releases and how the arrow is hitting the plunger spring. The plunger is not used to adjust for weak or stiff arrows as was suggested in this thread unless the archer is tuning for one specific distance. 

plungers are to tune for most forgiving group or tightest group. Not for spine issues of the shaft being too weak or too stiff. Anyone who does adjust plunger to correct a stiff or weak arrow will not get a good overall tune for the five FITA distances.


Chris


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## dchan (Jun 29, 2004)

chrstphr said:


> The plunger is used to adjust for different minute releases and make the majority of the releases consistent. A bow can be tuned to shoot a group with a rock hard plunger or with no plunger at all. Adjusting plunger for walkback tuning from 50 meters to 5 is done to adjust how the arrow is flying straight out of the bow based on the average of your releases and how the arrow is hitting the plunger spring. The plunger is not used to adjust for weak or stiff arrows as was suggested in this thread unless the archer is tuning for one specific distance.
> 
> plungers are to tune for most forgiving group or tightest group. Not for spine issues of the shaft being too weak or too stiff. Anyone who does adjust plunger to correct a stiff or weak arrow will not get a good overall tune for the five FITA distances.
> 
> ...


everything we do as a shooter will have an affect on "dynamic spine" Not being in alignment, torquing the bow, etc will all affect dynamic spine. That's why when one person tunes a bow for their own shooting, the same rig, even with the exact same DL may require a different spine. 

The plunger is part of the "dynamic spine" adjustment. It's a "fine" adjustment but it will change the dynamic spine.

From the FITA training manual

========================

Cushion Plunger Setting
When correcting fishtailing using the Bare Shaft Planing
Test, use the cushion plunger for fine adjustments only and
not for large horizontal adjustments. It is important to first
have good spine compatibility for the bow before using the
cushion plunger to correct gross errors in spine. In the fine
tuning process, the cushion plunger’s ability for improving
grouping will become evident. Also, it is important to note
that when adjusting the cushion plunger tension, it will al
-
most always affect nocking point height *as well as dynamic
spine.* Don’t be surprised if the bare shaft impacts change in
height as well as horizontal impact.
======================


and a little more from the FITA manual about why we tune..

========================================

Your shooting technique can have a large influence
over the dynamic properties of your arrow. Two archers
shooting the exact same bow, same poundage and the
same arrow length may not necessarily require the same
arrow size. Usually, the archer who has better “line”, (see
shooting form chapter for details on body alignment)
will shoot a lighter (weaker) spined arrow than an arch
-
er who has poor skeletal alignment. This is because the
archer with good alignment creates less side movement
of the string on release resulting in less initial bending of
the arrow shaft.
As will be shown shortly, there are a number of inter
-
acting tuning variables which can be employed to best
tune your system. There is not one unique set-up of these
variables to achieve the desired minimum group size you
are seeking. In fact, it is normal to be able to achieve a
good bow tune with more than one stiffness grade of ar
-
row. With this in mind, many people prefer to tune their
bow with a stiffer arrow because it is believed to be more
forgiving. Forgiving in this sense is that the arrow will
readily accommodate variations in the archers shooting
technique.


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## chrstphr (Nov 23, 2005)

i didnt say it wouldnt. I said it was not for that use. 

weakening the plunger to get the bare and fletched together at 25 yards, will make the arrows throw to the weak side the further out you shoot. While you have made an adjustment for the 25 yard target that works, you have effectively messed up/ weakened the throw for 35,40, 50,70, and 90 yard target. Now your shooter will constantly change the windage from 90 to 30 since the bow is not tuned with throw the arrow straight. If the shooter only shoots at 25 yards, then no harm no foul. But if the shooter is planning to shoot a number of distances, then he should use the limb poundage to get the bare and fletched together. Then use the plunger to fine tune the grouping. 

Chris


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## Viper1 (Aug 21, 2003)

dchan - 

Correct. 
It's been done that way for decades.
Each parameter has an optimal setting, but ALL are used. 
The trick is to not over compensate with any one.

Think about "fine tuning" this way:
If you spine tune with limb weight (limb bolt position) and then group tune with plunger position and tension, your limb weight will now be slightly off. 
So you readjust limb weight, and then you have to re-tweak the plunger.
Sure, you might narrow it down after a while, but then slight string creep, evolution of form, minor equipment changes, messes up the works. 
Repeat. 

For most non-elite shooters,
Set the limb bolts in mid throw. 
Do gross tuning by tweaking the limb bolts, finish with plunger position/tension and or brace height.
Don't over think tuning, for most of us, it's just not going to matter.

Viper1 out.


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## midwayarcherywi (Sep 24, 2006)

Viper1 said:


> dchan -
> 
> Correct.
> It's been done that way for decades.
> ...


I look at all the involved, sometimes convoluted, tuning posts and this post sums up how one should proceed beautifully. Ladies and gentlemen, KISS.


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## kshet26 (Dec 20, 2010)

While a great tune is always in fashion, 4-distance fitas are going the way of the dinosaur. So the issue of changing distances is less of a concern now, unless you're doing field or the like.


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## dchan (Jun 29, 2004)

lksseven said:


> But here is my point - I don't quite understand the admonition to 'quit tuning ad nauseum' and 'just go shoot'. I mean, when I'm chasing that tune, _all I'm doing is shooting_ - I have to shoot relentlessly to test my latest tuning recipe. And there's a good chance that when I'm in the hyper throes of tuning, I'm shooting with more attention to form than normal practice time, because I want any noticed variations from arrow to arrow to be a comment on the tune, not my form.
> 
> Having said that, I readily acknowledge that 'form' is king, 'tuning' is the queen.


Context!

One of the reasons I kept trying to get "experience or level of shooter" in to people's mind when asking for tuning help.

A lot of the people that were asking about tune or perfect arrow spine, etc, did not put into their question their level of shooting. In several cases it was fairly clear to me and several others that the poster in that case, was maybe 2 months into shooting, Still barely putting up 5" groups at 10 M and missing a 122cm bale from time to time, and blaming their tune or equipment. Or they were worried about being 3 spines off.. 

On the other side there are several people here that the tuning process is all part of the allure of archery. The hard part is understanding where the ROI or return on investment is important. Especially using a media like the internet with no visuals.

For alaz, if we go back a few months and look at some of his posts /threads and have followed his journey, we know he is at a point where it is now starting to take hold.. The experimentation and pursuit will probably achieve results. This is why in my posts to Alaz I noted "it may not be worth it" but gave my advice as to what would affect the changes. And also why I tried to explain the concept in more detail.


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## alaz (Mar 8, 2009)

This has been a very helpful thread on all ends for me. I have a better sense on how my equipment works together. I am happy with the improvement of my bare shaft flight, and I will return back to shooting and track my groups from here. Based on what I have read, I will adjust my plunger tension and see how it impacts my groups. I have to continue working on my form, I know that, but nice to know how to maximize my efforts.

I know Chris had mentioned tiller adjustment. If I noticed my bow tending to aim low (seems to be the case since I tightened the limb bolts some), what is the best approach. I will shoot for a few days to make sure that it is not the added weight, but looking for a direction just in case I decide to try that.
thanks again.


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## alaz (Mar 8, 2009)

lksseven said:


> Agree with Viper1 and Midway in their 'general' (agree with Chris on his very specific point, too).
> 
> I would throw in a comment that comes at this discussion from the side window ... for some of us, chasing the perfect tune is a quest that helps keep us 100% engaged. I find the chase for that perfect confluence of variables (and the understanding of the interplay between those variables) to be fascinating, and when found, a real Marlboro moment.
> 
> ...


I do not understand how your post is in the future??


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## dchan (Jun 29, 2004)

alaz said:


> I do not understand how your post is in the future??


I've noticed this behavior on and off for the past week or so. I think there is a bug or something going on with the servers.

I've already alerted the admin/technical team.

DC


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## lksseven (Mar 21, 2010)

Agree with Viper1 and Midway in their 'general' (agree with Chris on his very specific point, too).

I would throw in a comment that comes at this discussion from the side window ... for some of us, chasing the perfect tune is a quest that helps keep us 100% engaged. I find the chase for that perfect confluence of variables (and the understanding of the interplay between those variables) to be fascinating, and when found, a real Marlboro moment. 

But here is my point - I don't quite understand the admonition to 'quit tuning ad nauseum' and 'just go shoot'. I mean, when I'm chasing that tune, _all I'm doing is shooting_ - I have to shoot relentlessly to test my latest tuning recipe. And there's a good chance that when I'm in the hyper throes of tuning, I'm shooting with more attention to form than normal practice time, because I want any noticed variations from arrow to arrow to be a comment on the tune, not my form. 

Having said that, I readily acknowledge that 'form' is king, 'tuning' is the queen.


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## lksseven (Mar 21, 2010)

...


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## lksseven (Mar 21, 2010)

alaz said:


> I do not understand how your post is in the future??


Alaz,
That's the 'zen' that Bradd7 is always on about ￼


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## alaz (Mar 8, 2009)

lksseven said:


> Alaz,
> That's the 'zen' that Bradd7 is always on about ￼


I am only know beginning to understand....you guys are quite impressive! Nothing like the compound guys who only type in the present


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## chrstphr (Nov 23, 2005)

alaz said:


> I know Chris had mentioned tiller adjustment. If I noticed my bow tending to aim low (seems to be the case since I tightened the limb bolts some), what is the best approach.



with no stabilizers and or weights on the bow, draw bow several times and feel for pitch. does bow go up or pull down? does bow float. 
If bow is pulling down when you draw to aim, then lower limb is too strong. Weaken lower tiller bolt or strengthen upper tiller bolt.
If bow is pulling up when you draw to aim, then strengthen lower limb ( screwing in tiller bolt, or weaken top limb, loosening tiller bolt).

Once you have bow floating neutral during draw, then put on stabs and weights and recheck. re adjust to have bow float again during draw. 

Lastly, adjusting one limb tiller will move nocking point. Nocking point will have to be reset. 

Chris


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