Broadhead tuning question

[Zac]

I am having trouble understanding rest movements related to broadhead impact vs field points. If BH is left of FP there is a right tear. Rest correction would be to the left towards the BH. Moving the rest moves the front of the arrow and not the rear. I've heard reasoning for this state that you are moving the tail right tear left in line with the point. How is this happening if you are moving the front of the arrow further away from the back? This movement only makes sense to me if the string end was manipulated via yokes, Top Hats etc. That being said I know this is correct just feel like I'm missing something.

 

[Ucsdryder]

 

[Brendan]

So - my opinion, OP is right, and it's not intuitive: Rest movements are backwards posted in the post above. I've had other people disagree with this, and it's not that I doubt them, but I have yet to see anyone ever able to prove it by making small adjustments and posting results.

The way I think about it is this. When a bow is out of tune, the arrow and the powerstroke of the bow are not in alignment. You effectively want the powerstroke driving down the center of the arrow. You can either move the arrow (using the rest) or move the powerstroke (using yokes, shimming cams, flex guard)

My Notes:

Nock Right - Broadhead misses Left, Right Tear

Power stroke of the bow is to the left of the rest. You either need to move the power stroke to the right to align with the rest (via yokes, shimming cams, or adjusting your flex guard) or you need to move your rest to the left to align with the power stroke.

• Broadhead hitting left is the same as bareshafts hitting left or a tail right tear.
• Tighten Right Yoke
• Loosen Left Yoke
• Rest Left
• Shim Cam(s) to the Right
• Crank down flex guard for more sideways string pressure / more string clearance.
• Spine too Stiff (maybe)

Start here from Gillingham talking about it, some interesting nuggets in there.

Super Tuning your Bow

Learn how to get your bow and arrow set-up to achieve perfect arrow flight, everytime!

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[Trial153]

So - my opinion, OP is right, and it's not intuitive: Rest movements are backwards posted in the post above. I've had other people disagree with this, and it's not that I doubt them, but I have yet to see anyone ever able to prove it by making small adjustments and posting results.

The way I think about it is this. When a bow is out of tune, the arrow and the powerstroke of the bow are not in alignment. You effectively want the powerstroke driving down the center of the arrow. You can either move the arrow (using the rest) or move the powerstroke (using yokes, shimming cams, flex guard)

My Notes:

Nock Right - Broadhead misses Left, Right Tear

Power stroke of the bow is to the left of the rest. You either need to move the power stroke to the right to align with the rest (via yokes, shimming cams, or adjusting your flex guard) or you need to move your rest to the left to align with the power stroke.

• Broadhead hitting left is the same as bareshafts hitting left or a tail right tear.
• Tighten Right Yoke
• Loosen Left Yoke
• Rest Left
• Shim Cam(s) to the Right
• Crank down flex guard for more sideways string pressure / more string clearance.
• Spine too Stiff (maybe)

Start here from Gillingham talking about it, some interesting nuggets in there.

Super Tuning your Bow

Learn how to get your bow and arrow set-up to achieve perfect arrow flight, everytime!

www.youtube.com

This^


If your new to tuning the Gold tip chart that Tim made is the best tool you will find anywhere. I disagree with Tim on a host of issues but bow tuning isnt one of them. He got that down pat.

 

[5MilesBack]

I can't explain it, but I've had setups where moving the rest towards the BH's brought them together, and I've had setups where moving the rest towards the FP's brought them together. I just make adjustments until everything is consistently perfect at 60 yards with BH's and FP's.

 

[Brendan]

I can't explain it, but I've had setups where moving the rest towards the BH's brought them together, and I've had setups where moving the rest towards the FP's brought them together. I just make adjustments until everything is consistently perfect at 60 yards with BH's and FP's.

You and I have talked about this before. There's a nugget in one of Gillingham's videos that I think is it. He briefly mentions rest adjustments and the "Pervasive Nock Travel of the Bow" that can make things strange. I did observe in my testing that a miss in one direction with a broadhead was a lot easier and quicker to clear up with the rest than was a miss in the other direction. Basically, thinking about whether a rest movement is "fighting" or "cooperating with" your lateral nock travel. That's my theory anyways.

 

[OldGrayJB]

That diagram in the second post shows point of impact, not nock tear through paper, so it's correct also. I would broadhead tune and not worry about paper. Doing both at the same time is confusing.

You're not trying to guide the arrow with the rest. You're just trying to stabilize it as it leaves the bow. When you have a right nock tear, the point is trying to go left. Moving the rest left will put the arrow inline with the natural power stroke.

It's kind of like sighting in. You don't move your point of impact. You move your sight to the point where the arrow will fly.

 

[5MilesBack]

I did observe in my testing that a miss in one direction with a broadhead was a lot easier and quicker to clear up with the rest than was a miss in the other direction. Basically, thinking about whether a rest movement is "fighting" or "cooperating with" your lateral nock travel. That's my theory anyways.

I like playing around with this stuff so I always test both directions to see how it affects things. There's another thing though.......some rests will give you opposite indications, kind of like fletching contact can screw it up too.

 

[Zac]

These are all great replies. I've watched Tim's stuff years ago but I will touch up on them.

 

[Brendan]

I like playing around with this stuff so I always test both directions to see how it affects things. There's another thing though.......some rests will give you opposite indications, kind of like fletching contact can screw it up too.

You're right on the rest. How long it supports the arrow (and acts like a fulcrum) during the power stroke is probably a factor, as well as spring tension on the launcher, probably like angle / tension of a blade rest.

 

[Beendare]

I can't explain it, but I've had setups where moving the rest towards the BH's brought them together, and I've had setups where moving the rest towards the FP's brought them together. I just make adjustments until everything is consistently perfect at 60 yards with BH's and FP's.

Agreed, I've had the same thing happen.

Heres why, IMO;
I paper tune FP's first....then BH tune. There is a range of rest adjustments where paper tuning works....but then it gets refined down to one adjustment for BH's. It never takes more than 1/16" adjustment and its usually 1/32" or less to get my BH's tuned coming from Paper and FP's.

It seems that sometimes my paper tune overshot the center point....thus making rest adjustments the opposite.

Key is....small increment adjustments....

_________

 

[tsm213]

Now try shooting left handed lol. Nothing you read makes sense. I don’t adjust my rest for center shot I twist my yokes or shim the axles.
I started writing everything down for myself. Every bow -arrow -vane combo is slightly different.


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[5MilesBack]

Now try shooting left handed lol.

I'm left-handed.......Beendare's left-handed........how does the arrow and bow know which hand you're using to draw it back with, with a release?

 

[tsm213]

I'm left-handed.......Beendare's left-handed........how does the arrow and bow know which hand you're using to draw it back with, with a release?

It doesn’t know. But everything is backwards from tuning guides. I found it confusing.


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[Brendan]

I'm left-handed.......Beendare's left-handed........how does the arrow and bow know which hand you're using to draw it back with, with a release?

The main difference I can think of is direction of horizontal nock travel because of cables / flex guard tension.

 

[Brendan]

I don’t adjust my rest for center shot I twist my yokes or shim the axles.
I started writing everything down for myself. Every bow -arrow -vane combo is slightly different.

I do the same where possible - set rest straight down the center and tune with yokes / cams. But, not possible on every bow though. Take the Prime Centergy and Logic CT5. Can't shim the cams, no yokes to adjust. Your options are rest and flex guard or getting into swapping and shimming limbs.

And, there are times when I use a micro adjustment of the rest after yoke tuning or cam shimming to get things perfect.

 

[MTSasquatch]

I do the same where possible - set rest straight down the center and tune with yokes / cams. But, not possible on every bow though. Take the Prime Centergy and Logic CT5. Can't shim the cams, no yokes to adjust. Your options are rest and flex guard or getting into swapping and shimming limbs.

And, there are times when I use a micro adjustment of the rest after yoke tuning or cam shimming to get things perfect.

I had a Mathews for years, and switched to Prime when the Logic came out in ‘18. It was a learning curve in tuning. Most of my struggle has been just that, leaving cams/yokes and tuning with rest/flexis and even significant timing adjustments. My logic continuously wants to shoot knock high on even cam timing to the point where my sight was totally bottomed out. After 3 shops and numerous bouts of diagnostics, the only fix was adjusting my lower cam to put it out of time with the top by +1/2 inch measured static from cam to string to hold arrow on centershot. It was maddening to figure that out

 

[Jellymon1]

To get broadheads and field points together I move broadhead towards field points for my vertical adjustment, and field points towards broadheads for the horizontal adjustment. That is if I need to move my rest at all after yoke tuning, which is what I use for 95% of my horizontal adjustments. This has worked for every bow I’ve ever tuned that was tunable.