OL Tuning Question

[BobW]

Three bare shafts are hitting in the 6" bull.  Matching weight fletched shafts are hitting left of center, good group together, but also high.

Next step per instructions is to slightly lower nock..

Question:  The left of bare shafts with fletched shafts is supposed to be weak spine.  But, if bare shafts are hitting at center, it there possibly something else?

[drewsbow]

if it is consistant then follow da rules and cut slow :0)

[vermonster13]

Are you left handed? Otherwise they are a little stiff when fletched.

[BobW]

Drewsbow:  No-can-cut.  Need every inch of the shaft.  I draw 32+".

VT13:  Page 9 of 11 - "Bare Shafts Grouping Right" Reason - underspined.....That is what the book says.....

now what?

[vermonster13]

You said above the fletched shafts were hitting left, bareshafts bullseye. That means that when you fletch them you are stiffening them some. You want bare shafts a little right if the arrows are that close, and fletched in the bull.

[WESTBROOK]

Lighten up the point weight.

Eric

[drewsbow]

only thing from there is to drop some point weight or change to a stiffer spine.

[BobW]

So if I stiffen them all up (drop point weight), fletched should theoretically close the gap between them and the bare shafts?

I was lost on the fact that I was on the bull when bare shafted.....  

[BobW]

Eric:  these are the 250's w/ 225 up front.

[vermonster13]

Are you right or left handed Bob? If you are right handed, you will need to add some point weight to bring them together, if left handed then drop some point weight. If the fletched ones are hitting left.

[BobW]

I'm right handed...

I don't get it........that isn't what OL's Book says.....

[Jeff U]

VM13 - you've got it backwards.  He is under spined.

His fletched are hitting left of the bare shaft.  Or, bare shaft grouping to the right of fletched.  Same thing...

Fletched arrows group left = Bare shaft grouping right

From OL's site:

BARE SHAFTS GROUPING RIGHT

Reason: Under spined (weak)

Remedy: Lighter point. or thicker side plate, or shorter shaft, or switch from a DF-97 or FF string to Dacron, or new, stiffer arrows.

[vermonster13]

If the bare shafts are hitting center then they are spined just right for your bow when bare, adding fletching slightly stiffens an arrow(usually not enough to make a difference unless the arrows are real on border). So once you fletched them you stiffened them just enough to bring them left. Just try adding some point weight to the fletched ones and see what happens.

[vermonster13]

Look at the illustration on the bottom of this page on OL's site.

 http://www.bowmaker.net/index2.htm

[p1choco]

Hmmm, I thought adding fletch weakens spine some.  I'll have to make note of that.

[BobW]

I just copied this from the site (same as the one I have printed here on my lap):


BARE SHAFTS GROUPING RIGHT

Reason: Under spined (weak)

Remedy: Lighter point. or thicker side plate, or shorter shaft, or switch from a DF-97 or FF string to Dacron, or new, stiffer arrows.

Dang, that is driving me nuts....It was the fact that the bare shafts were "on" that is just causing my gears to jam....

Okay, I see what you are saying - yeah its my luck, I'm on the edge once again...been hearing that all along with both my bows (56#@32" and 59#@32").  will give it a try by weakening them a touch....(up the point weight).  Any incremental suggestions?  I'm about 6"-8" out.

[peak98]

His bare shafts aren't grouping to the right, they're dead on.....so adding the fletching stiffens them up a little causing them to shoot left of center for a right handed shooter.

[p1choco]

I just read OL's tuning and it does say

BARE SHAFTS GROUPING RIGHT
Reason: Under spined (weak)

I think Vermonster has it right on this one though because he also states "..., bare shafts grouping a little low and right is perfect because fletching makes a shaft react slightly stiffer."  

There is a difference between shooting a group off to the right and "a little to the right".  Glad I'm on track now.  I have some new arrows to tune.

[LazerRay]

Adding weight to the rear does stiffin an arrow.

[WESTBROOK]

I think OL means,"a little low and weak" = all arrows in a group with bare shafts in the low-weak part of the group.

If there is 6-8" difference in groups their still too weak. I would drop pt weight and bring them closer together.

Eric