Well that went badly. . .

[jeffp51]

I set out with a goal to make a set of arrows matched to my bow--matching spine, weight, and length.  I got a set of 4 garden stake bamboo arrows and matched them in spine to my best shooting fletched arrow.  they match each other in tip weight, length and spine to within 1/1000 of an inch.  --I have OCD sometimes, so sue me--  All of them rolled perfectly on a tabletop.

I have been reading up on bare shaft tuning, and watching lots of youtube videos.  I shot these at about 5 yards.  The first one hit like you see in the picture --extreme nock left/ point to the right.  Classic weak spine,  even though it was on the high side of the spine measured in my fletched arrows.  I thought I was being conservative. Anyway, the first one hit and snapped on impact.  I took the second one, cut it down by half an inch and shot.  Still nock right.  Cut off another half inch.  this time it looked better, so I shot it again, and it snapped. Guess I get some more bamboo and start over with stiffer shafts.  the tip was 133 grain--matching my good shooter, so I could cut it down some too, I guess.

Goal was a set of five.  Started with 7.  2 were way underspined before I finished them, so they go to kids bows.  two broke.  Probably not much point continuing with the other two if they are going to have the same problem.

What do you all think?  With fletchings all my arrows kinda shoot kinda okay.  I would like to eliminate at least one problem so I can see what my bad form is causing. . .

[jeffp51]

I am also wondering what effect brace hight will have on this.  It doesn't feel either high or low to me, but what do I know? 
Low brace height would cause        nock left/ nock right?
High brace height would cause       nock right/ nock left?


My mind can make brace height work either way, but it seems like low brace would be worse than high for shooting straight (on a non-center shot selfbow)

I should also mention I am right handed.

[TimBo]

Google "tuning longbows and recurves".  You should come up with a document by O.L. Adcock.  Read that through a few times - I found it to be helpful.  I don't think 5 yards is far enough to let the arrow recover (without fletching).  Also, I would use a bag of bags or some other softer target. 

[loon]

I have a very similar problem, also garden stakes but not that straight. sort of "snakey".
I don't think the arrow will recover without fletching... at 20 yards they just went totally sideways 'weak spined', at 5 yards or so it entered at an angle. One hit sideways at 20 yards so hard it broke. And that was without heads :\ also thumb draw, seems harder to shoot an arrow so it doesn't act weak with thumb draw. Only with fletchings, I can actually hit targets at 20 yards..

[jeffp51]

is that the bamboo, or how far we are from center shot on a self bow?  Without fletchings, my understanding is it will never recover--there is no force to counteract the initial push of the string.  Yet I see lots and lots of videos of fletchless arrows shooting pretty darn straight.

[loon]

is that the bamboo, or how far we are from center shot on a self bow?  Without fletchings, my understanding is it will never recover--there is no force to counteract the initial push of the string.  Yet I see lots and lots of videos of fletchless arrows shooting pretty darn straight.

saw a video of someone doing it with a turkish bow, not  center shot. guess the spine and release have to be perfect.. and/or need good forward of center - that might allow a fletchless arrow to recover. if the center of mass is behind of center  then of course it'd spin wildly.  but a heavier point would reduce spine :\ ah

[aaron]

I'd also like to know how centershot the bow is. my first guess is that you are getting a "false weak" reading, that is, your arrow is too stiff.

[loon]

I'd also like to know how centershot the bow is. my first guess is that you are getting a "false weak" reading, that is, your arrow is too stiff. Assuming you are right handed...

Arrow can land tail outside the bow if it's too stiff??

arrgh...

[aaron]

if the arrow is way too stiff, the nock bounces off the handle and kicks out, producing a false weak reading

[jeffp51]

I am right handed.  the bow at the pass is 1 and 1/8" thick, but the alignment is shaded toward the shooting side.  Hard to get a good measurement but between 1/4" and 3/8" offset from center.

Brace height is just over 7" measured from the back of the bow, and 6" from the belly.
Draw weight is 55# @ 29"

The arrows were spined at .447" of deflection and 32" long tip to tip. which on my chart makes them about 58#. 

[aaron]

hmm.. this extra info is good, but the proof is in the pudding as they say.  I'd try the same arrow with double the tip weight and see what happens. May sound counter intuitive, but i'm stickin to it.

[DC]

I set out with a goal to make a set of arrows matched to my bow--matching spine, weight, and length.  I got a set of 4 garden stake bamboo arrows and matched them in spine to my best shooting fletched arrow.  they match each other in tip weight, length and spine to within 1/1000 of an inch.  --I have OCD sometimes, so sue me--  All of them rolled perfectly on a tabletop.

I have been reading up on bare shaft tuning, and watching lots of youtube videos.  I shot these at about 5 yards.  The first one hit like you see in the picture --extreme nock left/ point to the right.  Classic weak spine,  even though it was on the high side of the spine measured in my fletched arrows.  I thought I was being conservative. Anyway, the first one hit and snapped on impact.  I took the second one, cut it down by half an inch and shot.  Still nock right.  Cut off another half inch.  this time it looked better, so I shot it again, and it snapped. Guess I get some more bamboo and start over with stiffer shafts.  the tip was 133 grain--matching my good shooter, so I could cut it down some too, I guess.

Goal was a set of five.  Started with 7.  2 were way underspined before I finished them, so they go to kids bows.  two broke.  Probably not much point continuing with the other two if they are going to have the same problem.

What do you all think?  With fletchings all my arrows kinda shoot kinda okay.  I would like to eliminate at least one problem so I can see what my bad form is causing. . .

About 7 lines up you say "still nock right". Did you mean to say left? Puzzled.

[Aaron H]

Arrow spine calculators are based on the assumption that your arrows are 28" over all length.  You have to subtract 5# of spine for every inch over 28".  With your 32" long arrows you must subtract 20# from your readings.  So your arrows are not actually 58#, but rather 38#.   This is why the are continually hitting nock left.

[jeffp51]

DC they definitely hit all nock left. Sorry for the mix up.
Aaron, I figured (after the fact) that the length was probably the culprit. I was trying to match an arrow that already shoots well. I guess I way underestimated the effect of the fletchings.

[Urufu_Shinjiro]

Yeah, I bet if you removed the fletching from your good arrow it would fly nock left too. Also bamboo is a little different than wood in it's behavior, the math and formulas can still be applied to help tune but I wouldn't expect a bamboo arrow and a wood arrow of the same specs to behave the same.

Loon, you're shooting thumb ring so when you read these tuning guides and such remember to reverse the right/left stuff...