Tuning confusion

[JAH518]

I've never run into this before so hopeing for some direction.

I'm helping a friend set up a new bow and can't get arrows to tune. The set up is 44lb @ his 27" bow appears to be center cut, shooting off a thin leather shelf pad with Velcro side plate. He shoots 3 under with a fairly constant release and no obvious signs of plucking.

Ever thing we try shows weak (nock left) into a bag and foam target. All arrows used are Axis trad.
 Started with 600 @ 29" 125g "weak"
500 @ 31" 150 and 125 "weak" cut 1/4 at a time down to 28" still weak but slightly better.
400 @ 31" 150 "weak" cut 1/4 at a time to 28.75 with 150 and start getting some weak and some stiff readings. 
I noticed the fresh Velcro side plate is show a lot of wear forward (target side).
We tried 2 different strings and several different placements of his silencers.

What is going on?

[BAK]

First thing I'd do is take the Velcro side plate off and shoot a few arrows with no side plate and see what happens.  "Soft" side plates can introduce a whole new problem into the equation as they act as a cushion.

[McDave]

This seems like a classic case of false weak.  False weak is when a shaft that is too stiff rebounds off the strike plate and shows weak when it is really too stiff.  There is no way that the .400 shaft should be showing weak.  The .600 shaft may actually be weak.  Try that one with 100 and 75 grain points and see what happens.  The .500 shaft should be tunable at some shaft length and point weight combination.  Forget about string and silencers at this point; that is definitely a fine tuning adjustment after everything else is about right.  Just make sure brace height is within specs.  You didn't mention nock high/low.  How is that doing and what is your nock height?

[M60gunner]

I would go along with McDave on this one. Can you see if he is torquing the string with his ring finger? This will cause what Dave said. Been there done that.

[JAH518]

This seems like a classic case of false weak.  False weak is when a shaft that is too stiff rebounds off the strike plate and shows weak when it is really too stiff.  There is no way that the .400 shaft should be showing weak.  The .600 shaft may actually be weak.  Try that one with 100 and 75 grain points and see what happens.  The .500 shaft should be tunable at some shaft length and point weight combination.  Forget about string and silencers at this point; that is definitely a fine tuning adjustment after everything else is about right.  Just make sure brace height is within specs.  You didn't mention nock high/low.  How is that doing and what is your nock height?

We played with brace height with out much change in any of the results. We're getting slight nock high and nock point is currently 1/2". this is my usual starting point.
Is it true that smaller diameter arrows like the Axis usually do tune weaker?

[JAH518]

I would go along with McDave on this one. Can you see if he is torquing the string with his ring finger? This will cause what Dave said. Been there done that.

I will pay attention that this evening when he comes over to shoot. I didn't notice is yesterday but didn't real look for it either. was mostly standing behind and above him watching arrow flight. I could clearly watch the arrow come right off the shelf nock right and stay that way all the way to the target.

[sveltri]

I just ruined a dozen Axis shafts because of a false weak reading.  I got in a hurry and it cost me.  What McDave said is exactly what happened to me.  On the other hand, if I ever get to go hog hunting I have a 700 grain arrow setup and ready to roll!!

[JAH518]

I just ruined a dozen Axis shafts because of a false weak reading.  I got in a hurry and it cost me.  What McDave said is exactly what happened to me.  On the other hand, if I ever get to go hog hunting I have a 700 grain arrow setup and ready to roll!!

just out of curiosity what Axis spine did you end up with and what bow and draw specs?

[FoCoBlackWidow]

I recently dealt with similar issues and it ended up being a false read. Shooting bare shafts and three-under, I was nock-high all the way up to 7/8" (way above anything I've had before). At that point, the reading flipped and I realized why I couldn't get consistent flight. Another thing you may or may not have done is adding a second nocking point. That makes a difference for me.

[JAH518]

FoCoBlackWidow, Are you saying your solution for false weak was lowering nock height and a second nock point?   

[sveltri]

[quote just out of curiosity what Axis spine did you end up with and what bow and draw specs?
[/quote]

53@28, drawn to 28 bob lee hardcore 340 a Axis cut to 28-7/8” 200 grain point 185grain insert/collar

[sveltri]

author=JAH518 link=topic=172427.msg2919487#msg2919487 date=1589918565]
FoCoBlackWidow, Are you saying your solution for false weak was lowering nock height and a second nock point?

I think I also had my nock point set too low which just added to the confusion

[FoCoBlackWidow]

I needed to raise my nock point and have a second one just below the nocked arrow. Having those fairly close together helped keep things consistent.

[JAH518]

[quote just out of curiosity what Axis spine did you end up with and what bow and draw specs?

53@28, drawn to 28 bob lee hardcore 340 a Axis cut to 28-7/8” 200 grain point 185grain insert/collar
[/quote]

wow 385 upfront, bet thats one hard hitting arrow set up.

[JAH518]

 

I needed to raise my nock point and have a second one just below the nocked arrow. Having those fairly close together helped keep things consistent.

 

[dragonheart]

Clearance issue with the quill needs to be checked.  Spray the back of the fletched arrow with dry foot powder spray and see where the arrow contacting.  The quill could be "hammering" onto the rest area and causing it to kick. 

[McDave]

The small diameter arrows I am familiar with are Victory VAPs.  I haven't noticed any differences between the marked spine on those and larger diameter Gold Tips compared with actual spine, although my experience is purely subjective.  What I have experienced with smaller diameter shafts if the bow is cut past center is occasionally the centerline of the shaft will get too close to the centerline of the bow to suit me and I have to build out the strike plate a tad so the small diameter arrow rides in about the same place as a Gold Tip would.

1/2” may be too low a nock height for 3 under shooting, although I hold 3 under and have some bows that like that nock height.  It is a caution though, because if the nock height is too low and the shaft is bouncing off the rest, it can throw everything off, including your spine indications.  However, if you're in the range of level to 5* nock high, I wouldn't worry about it.

[JAH518]

We adjusted nock height last night and replaced the Velcro strike plate with paper thin felt. Arrows are coming out with no nock high or low but everything is still showing weak.    I did see just the slightest string torque but nothing very obvious and was the same amount every shot. I could see what looked like the string rolling (twisting, coiling) as he drew in the direction that would pull the arrow to the riser. Could the slight torque (and I mean slight almost can tell) and the rolling of the string be all our problems? How do you correct this?

Could the thickness of his finger tabs also be causing some of the issues? He is using a Yost tab but with 2 of the Yost leather layers, to protect his girly fingers.      2 of those leather layers does seem to be rather thick in my opinion.

[Alexander Traditional]

Something has to be way off. Why don't you try shooting the bow?

[JAH518]

Something has to be way off. Why don't you try shooting the bow?

So wish I could but dealing with a golf related wrist injury in my bow hand. I have had him shoot a few of my bows with my arrow set ups and they shoot great but arrows are fletched and that can hide things.