# What is the physics behind the up and down of bare shaft tuning?



## jim p (Oct 29, 2003)

It has been my experience that a tail low bare shaft needs the rest lowered or the nock point raised. It also appears that the bare shaft is moved toward the fletched arrow.

What are your findings?


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## willy boy (Jan 28, 2013)

http://www.acsbows.com/bareshaftplaning.html


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## jim p (Oct 29, 2003)

I think that that article may be for recurve bows. I am interested in how to tune compound bows.


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## tialloydragon (Mar 14, 2013)

I find moving the fletched arrows' point of impact toward the bareshafts straightens out the bareshafts flight and ultimately they group together. If the rest groups outside of centershot , then i start twisting cables.


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## bplayer405 (Jan 7, 2014)

You have to have your dl and form pretty much right to get good results when bareshafting. Being consistent and shooting multiple times is the best way to be accurate when reading what the bareshaft is doing. I don't try to group tune bareshafts. I shoot a fletched into a good foam target then shoot a bareshaft a couple inches away from the fletched and compare the bareshaft's angle to the fletched. I'm looking for the bareshaft to be parallel to the fletched in the horizontal and vertical plane. I read the nock end of the bareshaft and adjust just like paper tears. (Nock end of bareshaft angled left when compared to fletched = left tear, and so on.) Works great for me. Then I move on to broadhead tuning where I do group tune.

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## gofor (Feb 4, 2013)

jim p said:


> It has been my experience that a tail low bare shaft needs the rest lowered or the nock point raised. It also appears that the bare shaft is moved toward the fletched arrow.
> 
> What are your findings?


My experiences mirror yours. My theory as to the physics:

The force applied to the arrow is trying to drive it in the direction that the nock point takes as the string moves forward. If the arrow shaft is not perfectly aligned, the arrow will exit the bow canted in some direction. The air moving past the fletchings will align them ( and subsequently the arrow shaft) with the direction the arrow is pushed, so the fletched will hit closer to this point than an arrow with no correction (i.e the bare shaft). So by making adjustments to get the bare shaft closer to where the fletched shafts hit is bringing the bare shaft more in line with direction of the string force. When everything is in alignment, the fletchings are no longer "correcting" the arrow flight, so all hit together.

Of course, I could be wrong. LOL

Go

All that said, when making adjustments in one direction doesn't work, I always try making them in the opposite direction before going back and starting from scratch.


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## jim p (Oct 29, 2003)

Thanks for the replies. There are many things that can cause tuning problems such as nock fit. But on average it seems that for vertical bare shaft tuning the bare shaft is moved toward the fletched arrow and for horizontal bare shaft tuning the fletched arrow is moved toward the bare shaft. This seemed strange to me but it seems to work.

I have another post about horizontal bare shaft tuning. I wanted to break the two tuning directions apart just so that this strange affect could be discussed.


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## nuts&bolts (Mar 25, 2005)

jim p said:


> Thanks for the replies. There are many things that can cause tuning problems such as nock fit. But on average it seems that for vertical bare shaft tuning the bare shaft is moved toward the fletched arrow and for horizontal bare shaft tuning the fletched arrow is moved toward the bare shaft. This seemed strange to me but it seems to work.
> 
> I have another post about horizontal bare shaft tuning. I wanted to break the two tuning directions apart just so that this strange affect could be discussed.


Vertical tuning for BARESHAFT versus fletched is the easier one to fix. JUST change your cam UNSYNC. FINE tune the cam UNSYNC. For a single cam bow, this is untwist or twist the buss cable by half twists per adjustment....each time you goto the bow press. FOr a hybrid cam system, work the control cable, in just half twist adjustments, each time you goto the bow press. Send a pm to eventhorizon and ask him about VERTICAL tuning for bareshafts and broadheads. There is yet ONE more method. His results have been amazing. Ask him about. Tell eventhorizon I sent ya.


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## skidge (May 3, 2014)

I have bare shaft tuned a few bows now and it feels great to hit the mark with unfletched arrows. Your arrows just fly straighter than a witches pecker BUT, Every time someone asks me to help them with theirs I always forget how especially with vertical adjustment and slight yoke tuning. So, say for tail high tear, bare shaft hitting higher, do you advance or ****** top cam with control cable. Sideways, yes I know DL first, for say left tear, bare shaft left, do you twist yoke to change cam lean so the bottom of the top cam leans more to the left or to the right? This would be for a right handed shooter. Again, I know the rules for left and right bare shaft pertaining to draw length, I do not disagree but let's leave that part out. And I think I understand that with high tear it means more string is being taken up, let out on your top cam versus bottom cam, so advance it or ****** it? Thx


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## nuts&bolts (Mar 25, 2005)

skidge said:


> I have bare shaft tuned a few bows now and it feels great to hit the mark with unfletched arrows. Your arrows just fly straighter than a witches pecker BUT, Every time someone asks me to help them with theirs I always forget how especially with vertical adjustment and slight yoke tuning. So, say for tail high tear, bare shaft hitting higher, do you advance or ****** top cam with control cable. Sideways, yes I know DL first, for say left tear, bare shaft left, do you twist yoke to change cam lean so the bottom of the top cam leans more to the left or to the right? This would be for a right handed shooter. Again, I know the rules for left and right bare shaft pertaining to draw length, I do not disagree but let's leave that part out. And I think I understand that with high tear it means more string is being taken up, let out on your top cam versus bottom cam, so advance it or ****** it? Thx


Control cable and buss cable wrap around the bottom cam pulleys in opposite directions. So, when you remove a twist from the control cable, you can get the SAME bareshaft effect, by adding a twist to the buss cable. Your choice. TAIL high paper tear, is the same as BARESHAFT HITTING LOWER than fletched. TAIL LOW paper tear, is the same as BARESHAFT hitting HIGHER than fletched. PAPER tears refer to what the NOCK is doing. So, a TAIL HIGH paper tear is a NOCK that is ripping the paper TAIL HIGH. So, when your bareshaft is skidding through the air, TAIL HIGH, the bareshaft will hit the target LOWER than fletched arrows. Bareshaft skidding through the air TAIL HIGH, the TOP limbs are working TOO HARD. Too much CAM windup, on the TOP axle. So, we need to UNWIND the top cam, so the TOP limbs work LESS hard. HOW do you UNWIND the top cam at full draw? Well, IMAGINE the bow at full draw. SO, we want to UNWIND the top cam, we LENGTHEN the control cable. So, UNTWIST the control cable, half a twist or a full twist...and see what happens.


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## skidge (May 3, 2014)

So, for tail high, bare shaft low, advance the top cam, via the control cable, in comparison to the bottom cam correct?


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## tialloydragon (Mar 14, 2013)

skidge said:


> So, for tail high, bare shaft low, advance the top cam, via the control cable, in comparison to the bottom cam correct?


Correct

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## Glamsland (Apr 14, 2015)

nuts&bolts said:


> Control cable and buss cable wrap around the bottom cam pulleys in opposite directions. So, when you remove a twist from the control cable, you can get the SAME bareshaft effect, by adding a twist to the buss cable. Your choice. TAIL high paper tear, is the same as BARESHAFT HITTING LOWER than fletched. TAIL LOW paper tear, is the same as BARESHAFT hitting HIGHER than fletched. PAPER tears refer to what the NOCK is doing. So, a TAIL HIGH paper tear is a NOCK that is ripping the paper TAIL HIGH. So, when your bareshaft is skidding through the air, TAIL HIGH, the bareshaft will hit the target LOWER than fletched arrows. Bareshaft skidding through the air TAIL HIGH, the TOP limbs are working TOO HARD. Too much CAM windup, on the TOP axle. So, we need to UNWIND the top cam, so the TOP limbs work LESS hard. HOW do you UNWIND the top cam at full draw? Well, IMAGINE the bow at full draw. SO, we want to UNWIND the top cam, we LENGTHEN the control cable. So, UNTWIST the control cable, half a twist or a full twist...and see what happens.


I needed to get my bs UP to meet the fletched. So i untwisted the control cable. Got the bs together with fletched in the end ,but i almost remowed all the twists i the control, so i added som to the bus. 
When i started the timing marks wav on the marks.
Can this be a sign of a to high nock poin to start with?
Its not normal to untwist the control all the way! 
But they hits nice together... I guess next time i will find som better startingpoint, check the nock point first, that its 90 degre on the string..??


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## nuts&bolts (Mar 25, 2005)

Glamsland said:


> I needed to get my bs UP to meet the fletched. So i untwisted the control cable. Got the bs together with fletched in the end ,but i almost remowed all the twists i the control, so i added som to the bus.
> When i started the timing marks wav on the marks.
> Can this be a sign of a to high nock poin to start with?
> Its not normal to untwist the control all the way!
> But they hits nice together... I guess next time i will find som better startingpoint, check the nock point first, that its 90 degre on the string..??


You can ADD more twists to the buss cable, or you can remove twists from the control cable, to have the SAME effect. THIS is because the control and the buss cable wrap around the bottom axle, in opposite directions. IF you have removed nearly ALL the twists out of the control cable, and you don't like the look....*you can ADD MORE twists to the buss cable*...MORE than you already added to the buss cable, and *make your bareshafts HIT TOO HIGH*. Then, cuz your BARESHAFTS are NOW hitting TOO HIGH, cuz you added TOO MANY twists to the buss cable...you can FIX this, by *ADDING more twists back into the control cable*, to make your control cable look MORE pretty.


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## nuts&bolts (Mar 25, 2005)

Glamsland said:


> Can this be a sign of a too high nock point to start with?


Correct. If you put the d-loop just PLAIN too high, if your cables are LONG enough, we can make ANY nock point work...even a TOO high nock point. In your case, you almost ran out of twists to remove from the control cable.


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## jim p (Oct 29, 2003)

Who is going to answer this question. When horizontal tuning you move the fletched arrow toward the bare shaft but when vertical tuning you move the bare shaft toward the fletched arrow. Why?


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## nuts&bolts (Mar 25, 2005)

jim p said:


> Who is going to answer this question. When horizontal tuning you move the fletched arrow toward the bare shaft but when vertical tuning you move the bare shaft toward the fletched arrow. Why?


Toe-MAY-toe...or toe-MAH-toe. Just perspective. The bareshaft is ALWAYS telling you WHERE the bowstring is pushing the projectile. Arrows with VANES, are trying to COURSE correct the projectile. Exactly like a rudder on a boat. So, horizontal or vertical tuning...SAME difference. People ALWAYS say that their FIXED blade broadheads are hitting RIGHT of the fletched arrows. I say the FLETCHED field points are missing LEFT of the fixed blade broadheads. People say that their BARESHAFTS are missing to the RIGHT of fletched field points. I say that FLETCHED field points are missing to the LEFT of the bareshafts. HOW do you make FLETCHED arrows that are missing LEFT of bareshafts....HOW do you make the FLETCHED field points hit CLOSER to the BARESHAFTS?

Simple. 1) move the arrow rest to the RIGHT...and/or 2) TWIST the LEFT side yoke leg, cuz this FORCES the top cam to TWIST the limb tips and the top cam will point MORE to the RIGHT, which PUSHES your FLETCHED field point arrows to hit MORE to the RIGHT. So, which moved? Did the bareshafts moVE? Nope. So, did the FLETCHED field point arrows moVE? Yup, when you MOVE the arrow rest to the RIGHT, the VANES have LESS steering correction to do, cuz now your ARROW rest is pointing in the SAME direction of PUSH, as the bowstring is PUSHING. DUH.


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## nuts&bolts (Mar 25, 2005)

jim p said:


> Who is going to answer this question. When horizontal tuning you move the fletched arrow toward the bare shaft but when vertical tuning you move the bare shaft toward the fletched arrow. Why?


Vertical tuning. NO, moving the arrow rest UP or DOWN, is NOT the same as fixing your nocking point. So, if your BARESHAFTS are diving, NOSE diving DOWN and HITTING LOWER than fletched field point arrows...are BARESHAFTs missing LOW compared to FLETCHED field points or are FLETCHED field points missing HIGHER than bareshafts? The FLETCHED field point arrows are MISSING HIGH above the BARESHAFTS. WHY are the FLETCHED field points missing HIGHER than the bareshafts? The FLETCHINGS, the VANES are providing STEERING correction. So, the TOP cam is winding UP TOO HARD, so the TOP cam, and the TOP LIMB are over-powering the bottom limb. So, the TAIL END of the arrow is SKIDDING through the air TAIL HIGH, and the VANES FORCE the BACK end of the arrow DOWN, cuz that is what STEERING SURFACES do...RUDDER on a boat or an airplane, and so the FLETCHED arrows are miSSING HIGH compared to the BARESHAFTS. So, HOW do you MAKE the TOP limb work LESS HARD? Simple. 1) MOVE the d-loop down LOWER and/or 2) WINDUP the top cam less. HOW do you wind up the TOP cam LESS? YOU UNWIND the top cam, by making the control cable LONGER (remove twists). IMAGINE the top cam at full draw. So, what happens when you UNTWIST the TOP end loop of the control cable? The top cam UNWINDS a little bit, and when you UNWIND the top cam a little bit at full draw, you bend the TOP LIMB a little LESS. BEND the top limb a little LESS at full draw, then the TOP LIMB works LESS HARD, and the FLETCHED FIELD point arrow will fly a TINY BIT LESS TAIL HIGH. When you have the TOP limb and the BOTTOM limb in balance, fletched arrows will NO LONGER MISS HIGH, compared to the BARESHAFTS.


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## jim p (Oct 29, 2003)

I think that it is just the way that I am looking at the tuning.


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## nuts&bolts (Mar 25, 2005)

jim p said:


> Who is going to answer this question. When horizontal tuning you move the fletched arrow toward the bare shaft but when vertical tuning you move the bare shaft toward the fletched arrow. Why?


Horizontal or VERTICAL Tuning, when you FIGURE OUT how to tune the bow for PROPER arrow flight, this means the VANES have NO steering correction work to do. This means, you have the arrow rest SIDEWAYS position, adjusted SIDEWAYS to line up the arrow rest with the DIRECTION OF bowstring push. So, move the arrow rest right or left, and when you figure it out, when you move the arrow rest SIDEWAYS enough, to BLOCK the direction of BOWSTRING PUSH, you will get BARESHAFTS and fletched field points to HIT together. BUT BUT BUT, you don't WANT to move the arrow rest sideways position. BY GOLLY, I'm gonna force the bow to do my will, and I INSIST on the arrow rest sideways position at exactly 13/16ths. FINE. Then, if you INSIST on the arrow rest SIDEWAYS position at 13/16ths, your ONLY OPTIONS are to TWIST the TOP limb tips, by YOKE TUNING...and your ONLY OTHER OPTION is to FIX your draw length, and your form, until you STOP pulling sideways on the bowstring. That's the bottom line. You get a LEFT paper tear, for a Right handed shooter, cuz the form just plain SUCKS and the draw length is TOO LONG, and when the draw length is TOO LONG, you pull SIDEWAYS on the bowstring. GET The draw length correct, and the shooter no longer pulls SIDEWAYS on the bowstring, SIDEWAYS LEFT, when the draw length is too long...to the REAL Fix to a LEFT paper tear is to fix your form and get the RELEASE elbow in line behind the arrow. IF the draw length is only a LITTLE bit too long, you can FAKE it, with YOKE tuning and PULL DOWN on the LEFT yoke leg (add twists).


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## nuts&bolts (Mar 25, 2005)

jim p said:


> I think that it is just the way that I am looking at the tuning.


Yup.


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## tsilvers (Nov 16, 2002)

Any fool who claims left and right tears are solely a result of poor form and draw length is exactly that... a fool... Sounds to me someone needs to go back to the boyscouts....


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## enewman (Jun 5, 2007)

tsilvers said:


> Any fool who claims left and right tears are solely a result of poor form and draw length is exactly that... a fool... Sounds to me someone needs to go back to the boyscouts....


Then what does a left/right tear mean


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## tsilvers (Nov 16, 2002)

enewman said:


> Then what does a left/right tear mean


Simple.. it means ur nock point moves laterally through the shot.. in other words it doesn't stay on the same plane from static to full draw.. Lateral loading of the cable rod guide and cam lean are the primary cause of left and right tears.. not draw length...lol... if you have cams that don't rotate in the same plane or at least fairly close... u won't have have good tears... for anyone to claim by simply changing draw length will eliminate all lateral tear issues... well that's just ignorant... good luck.. 

There are several variables in addition to this they have some contribution including form discrepancies... it simply is not just a draw issue...


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## cloquet (Jan 12, 2004)

Subscribed


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## nuts&bolts (Mar 25, 2005)

enewman said:


> Then what does a left/right tear mean


I know you know, but we can all wait for tsilvers to en-LIGHT-en us.


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## tsilvers (Nov 16, 2002)

nuts&bolts said:


> I know you know, but we can all wait for tsilvers to en-LIGHT-en us.


I think it's beyond you...


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## archeryshooter (Apr 11, 2004)

tialloydragon said:


> Correct
> 
> Sent from my LGMS631 using Tapatalk


Does the nock point affect this as well? Do most bows perform better level with burger hole? Thanks


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## tialloydragon (Mar 14, 2013)

archeryshooter said:


> Does the nock point affect this as well? Do most bows perform better level with burger hole? Thanks


Yes, moving the nock point up will have a similar effect as advancing the top cam, but it pulls your point of impact down, and your arrow would no longer be 90 degrees to the string at brace (which i believe is a sign of a well-tuned setup.) That said, some bows tune better when the nock point is slightly higher than level.

As for the berger hole, there really is no correct answer to that. It depends on the bow, the rest, and your nocking point. Most bows could probably be tuned to shoot above, below, or right down the center and work just fine.

Use the berger hole as a starting point with the arrow 90 degrees to the string, and let the results tell you what to do next.

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## archeryshooter (Apr 11, 2004)

So is all this going to effect how the bow holds while aimin


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