Tuning confusion

[McDave]

“We adjusted nock height last night and replaced the Velcro strike plate with paper thin felt.”

This, combined with skinny shafts, could result in the condition I discussed where the centerline of the arrow shaft is on or inside of the centerline of the bow, which could cause a false weak indication.  The arrow shaft should be just outside the centerline of the bow.

[Alexander Traditional]

From the bows I have 600 spine should get you where you need to be. I think you said it was center cut so that should be good. 600 with a 125 should be stiff with a 125 grain tip I would think.

Do you have some of those 600 29" that have feathers on them? I would take one with feathers,and cut to 29" I would start with 175 grain and go up,and just watch the flight. I've seen thread after thread where people are trying bare shafting,and are shooting arrows for a 60 pound bow out of 45 pound bow,and then people telling them well you got to go with what the bare shaft tells you,and it gets people very confused.

[JAH518]

McDave, I haven't looked at that but will. It makes since, if it's inside than the bow is pushing the arrow into the riser causing it to bounce.

Alexander Traditional, I completely understand what your saying. I was estimating 600's or long 500's to work well with his set up. On one of my setups I followed the bare shaft tuning into a 340 spine. even though bare shaft flew great once I fletched them and I was getting fletching contact on my bow hand and outer edge of the shelf. Went back down to a mid length 400 that showed slight weak. When fletched they flew like darts and paper tuned perfect.   

[MSwickard]

You mentioned everything is hitting the target nock left.  Question to you:

If aiming at center of the target where are the arrow points impacting, left of center or right of center, dead center?

Are you bare shaft tuning?

You didn't mention type of bow? recurve, longbow (deflex/reflex)?  Type of string?

From what I can determine a 500 spine arrow at around 30" w/ 150 pt should be spot on if cut to center.  Get a good measurement of where the sight window is cut too since this is going to affect spine the most.  Also, if it's cut past center then you will more than likely be in a 400 spined arrow.

I would not worry about the tail too much but get the shafts to impact dead center. Do this close to the target like you would be paper tuning, then work your way back.   Then see if a bare and fletched shaft impact in the same group.

[JAH518]

You mentioned everything is hitting the target nock left.  Question to you:

If aiming at center of the target where are the arrow points impacting, left of center or right of center, dead center?

Are you bare shaft tuning?

You didn't mention type of bow? recurve, longbow (deflex/reflex)?  Type of string?

From what I can determine a 500 spine arrow at around 30" w/ 150 pt should be spot on if cut to center.  Get a good measurement of where the sight window is cut too since this is going to affect spine the most.  Also, if it's cut past center then you will more than likely be in a 400 spined arrow.

I would not worry about the tail too much but get the shafts to impact dead center. Do this close to the target like you would be paper tuning, then work your way back.   Then see if a bare and fletched shaft impact in the same group.

center bulls eye if anything slight right maybe an inch.
all shots bare shaft from 10-15 yards.
bow is a reflex/deflex and we have tried 3 different strings. 1st. mercury 14 strand, 2nd. mercury 18 strand, 3rd b-99 16 strand.   

[MSwickard]

I would take the shaft spec's that are hitting dead center with the point weight and overall arrow weight you are wanting and fletch up an identical arrow then compare.  If the bares and the fletched are grouping together should be good to go.

[Petrichor]

Three suggestions. One if he is tuning with a cant to the bow the readings will be turned with the cant. A weak reading could easily be a nock height issue (probably too low). I shoot three under and my nock height is usually between 3/8s and 5/8s. Second have another shooter shoot the bow and see if it reacts the same. If no problem with second shooter (use slowmo video on iphone to see exactly what's happening). You'll be surprised what a slowmo video will show you. Check the paradox by shooting the video in line with arrow over his shoulder and a second focused on his releasing hand. Three in my experience bareshaft tuning rarely works with newer shooters, so take this into account (I'm getting away from bareshaft all together). Clay hayes has a video where he tunes with fletching on and uses a slow mo video to help make adjustments. Then when he's close he throws broadheads on to finish the process. Now if you are dead set on doing bareshaft DO NOT shoot all shafts unfletched (maybe I misread) but if you have all bareshaft you have nothing to compare to ( and too much emphasis imo is placed on nock direction because so many things can affect it). Use groups of two to three fletched shafts with two to three bareshaft and make adjustments only after shooting a few groups. If bares are consistently right of fletched (weak), left of fletched (stiff), intermingled good to go to next step. Then fletch all arrows, shoot 3 broadheads and three field points same adjustments. Broadheads will just exaggerate adjustments that need to be made. By this point I wouldn't change the arrow more than an 1/8 if inch at a time.  Once broad heads and fields group together call it quits.  Best of luck.

[JAH518]

3rd night of working with my buddy and his bow has left us still in a cloud of confusion. last night we worked on videoing the arrow flight and his release. Wasn't able to get a good view of the arrow coming off the shelf but could clearly see the arrow flying nock left all the way to the target. We did see that one combo flew nock left but right at the 20yd target would correct and only show a slight left nock in the target. We also were able to get a arrow to consistently fly stiff (nock right) however we had to use a axis 340 with 150 upfront.

At the end of the night I wanted to try shooting and eliminate his finger release just to see if it would make a difference. I pulled out a compound wrist release and had him put a few down range. I had high hopes this would show us a different arrow flight good or bad but the results was the exact same. 

 for a last ditch effort on the night I put a 30.5" Axis with a 75gr Ethics insert and 25gr Ethics outsert and a 150gr point in his hands. The result was the closest to good arrow flight we've seen but with a combo of slight nock right and nock left out of 15 shots.

Could his little RF/DF longbow @ 44lb actually like a 30.5" 532gr 400 spine arrow with 235gr up front? I would have bet this was possible with a 500 spine but not 400. 

[MSwickard]

The only thing I can come up with is the shelf is cut past center and the low stretch string is needing a stiffer spine. Be interesting to see what it did with B50 or B55 string?

[Alexander Traditional]

This thread really got me to thinking. I took out a 46 pound bow at my draw,and had some carbon express that are 29" with brass inserts,and could not get them to fly good all the way up to 300 grains.

I have some aluminum 1916 that flew great.

Very weird thing you got going on there,I'm fresh out of ideas

[JAH518]

This thread really got me to thinking. I took out a 46 pound bow at my draw,and had some carbon express that are 29" with brass inserts,and could not get them to fly good all the way up to 300 grains.

I have some aluminum 1916 that flew great.

Very weird thing you got going on there,I'm fresh out of ideas

I know right, just can figure it out. Just for the heck of it he's going to bring some 600 and 700 spine dark timbers he bought for his wife and son over tonight. It couldn't hurt to try. I'm out of ideas too. Guess he's just going to need to put some flu flu feathers on a random spine and have fun. LOL!!

 

[JAH518]

The only thing I can come up with is the shelf is cut past center and the low stretch string is needing a stiffer spine. Be interesting to see what it did with B50 or B55 string?

what is the proper way to measure the shelf to see if it is truly cut to center or past center?

[Petrichor]

This reminds me of a custom bow where I could not get a shaft to fly weak no matter what poundage the shaft. I still don’t know what’s wrong with that bow (Maybe ill do something with it some day) but I always suspected the way the shelf was cut itself Was causing the issue. I had friction marks more than usual all over every rest material I tried.  I feel like something is hitting the arrow as it leaves the bow causing the weird flight. Have you tried it either wood arrows? Some bows are picky on material. Truly bare shelf it and see what it does. I’m gonna think on it some more. I would try a cheap I all weather rest to see how it shoots with an elevated rest. Or turkey feather if you prefer. What kind of bow is it?

[JAH518]

This reminds me of a custom bow where I could not get a shaft to fly weak no matter what poundage the shaft. I still don’t know what’s wrong with that bow (Maybe ill do something with it some day) but I always suspected the way the shelf was cut itself Was causing the issue. I had friction marks more than usual all over every rest material I tried.  I feel like something is hitting the arrow as it leaves the bow causing the weird flight. Have you tried it either wood arrows? Some bows are picky on material. Truly bare shelf it and see what it does. I’m gonna think on it some more. I would try a cheap I all weather rest to see how it shoots with an elevated rest. Or turkey feather if you prefer. What kind of bow is it?

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[McDave]

The only thing I can come up with is the shelf is cut past center and the low stretch string is needing a stiffer spine. Be interesting to see what it did with B50 or B55 string?

what is the proper way to measure the shelf to see if it is truly cut to center or past center?

This is a link (I hope) to a page where I posted a photo of how I determine how a bow is cut with respect to centershot, and whether the arrow is correctly oriented on the shelf.

http://www.tradgang.com/tgsmf/index.php?topic=169718.msg2888962#msg2888962

It helps if you have a pickup truck tailgate or something similar where you can prop the bow and then stand back and line up the string with the center of the bow with your eye.

I kind of doubt that a short r/d longbow is cut much past center.

[JAH518]

The only thing I can come up with is the shelf is cut past center and the low stretch string is needing a stiffer spine. Be interesting to see what it did with B50 or B55 string?

what is the proper way to measure the shelf to see if it is truly cut to center or past center?

Very informative, Thank you.

This is a link (I hope) to a page where I posted a photo of how I determine how a bow is cut with respect to centershot, and whether the arrow is correctly oriented on the shelf.

http://www.tradgang.com/tgsmf/index.php?topic=169718.msg2888962#msg2888962

It helps if you have a pickup truck tailgate or something similar where you can prop the bow and then stand back and line up the string with the center of the bow with your eye.

I kind of doubt that a short r/d longbow is cut much past center.

[MSwickard]

One way to measure, is to find the center of the limb and mark it.  You can verify this by stringing up the bow and sighting down the limb to see where the string dissects the limb.  Then measure from this center line to the strike plate.   

[Skipmaster1]

Pay close attention to his bow arm. A collapse on the front end, even as little as 1/8th inch can cause false weak readings.

[Tall Paul]

According to Ken Beck of Black Widow Bows, you shouldn't base your tuning on arrows in the target.  You should let the shooter concentrate on form, and have someone else watch the arrow flight from behind.  He says you should base the tuning on how the arrow is flying just before it hits the target.

[Petrichor]

According to Ken Beck of Black Widow Bows, you shouldn't base your tuning on arrows in the target.  You should let the shooter concentrate on form, and have someone else watch the arrow flight from behind.  He says you should base the tuning on how the arrow is flying just before it hits the target.

I second this which is why I tune with my buddy filming slow mo behind me on an iPhone.