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Author Topic: Increasing spine?  (Read 5281 times)

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Don Case

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Increasing spine?
« on: April 22, 2014, 02:19:52 pm »
I bought some 3/8" dowelling of mystery wood(possibly maple). It's beautifully straight. Comes in 6' lengths. I thought I was on to something. I put it on my newly built spine tester and it measured .700 deflection, about 37-40 lbs or so. My bow is 55#. Does this sound like it's in the ballpark since I have to subtract some weight for selfbow, some for point etc? Is there any way of increasing static spine if I'm too light?
Thanks
Don
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Offline PEARL DRUMS

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Re: Increasing spine?
« Reply #1 on: April 22, 2014, 02:36:12 pm »
How long are you cutting them Don? You'll lose 5# every inch under 28" BOP. As far as adding spine? I know of two ways: Shorter arrows or lighter tips. I suppose wiping several coats of sealer on may add a pound.
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Don Case

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Re: Increasing spine?
« Reply #2 on: April 22, 2014, 02:50:29 pm »
They'll be about 28- 30 inches I think. Kind of ashamed to admit it but I'm having a heck of a time trying to pull this new bow so I won't know the length for sure til I man up a bit and see just how far. I can manage 40# OK but 55# makes me grunt a touch( a big touch :-[ :-[ )
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Don Case

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Re: Increasing spine?
« Reply #3 on: April 22, 2014, 03:07:24 pm »
I just read a bunch of posts about spining. I made my spine tester using some old plans and made it 26". So now I have to modify it to make it 28". That will make the shaft deflect more. These new dowels are getting softer by the minute. I'm thinking I bought garden stakes for my wife.
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Offline PEARL DRUMS

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Re: Increasing spine?
« Reply #4 on: April 22, 2014, 03:10:14 pm »
26" centers are correct, don't change that on your tester. If they spined 37-40, they will be 27-30 out to 30". They wont work for your bows.
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Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Don Case

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Re: Increasing spine?
« Reply #5 on: April 22, 2014, 03:18:45 pm »
They'll sure make nice garden stakes. One of them is fletched too.
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Offline PEARL DRUMS

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Re: Increasing spine?
« Reply #6 on: April 22, 2014, 03:21:24 pm »
Very nice stakes, or 45-50# arrows that are 26-27" long. Im 6' 1" and draw 27.5" if I squeeze my cheeks together. I shoot 28-28.5" bop arrows.
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Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Don Case

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Re: Increasing spine?
« Reply #7 on: April 22, 2014, 04:13:21 pm »
bop???
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Offline PEARL DRUMS

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Re: Increasing spine?
« Reply #8 on: April 22, 2014, 04:14:47 pm »
Back of point
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Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline koan

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Re: Increasing spine?
« Reply #9 on: April 22, 2014, 05:25:14 pm »
I havent tried it yet, but i would think you could "toast" it some with heat to increase spine... Has anyone tried this?.... Brian
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Offline Pat B

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Re: Increasing spine?
« Reply #10 on: April 22, 2014, 06:37:04 pm »
That's worth a try, Brian. Tempering should increase the spine a bit.
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Offline okie64

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Re: Increasing spine?
« Reply #11 on: April 22, 2014, 06:38:13 pm »
Cut one of them as short as possible for your draw and drop to 100 grain points and see how it flies. Kinda like PD said, about 26-27" should work out for 50lbs or so.
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Offline Danzn Bar

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Re: Increasing spine?
« Reply #12 on: April 22, 2014, 06:38:55 pm »
Quote from: koan on April 22, 2014, 05:25:14 pm
I havent tried it yet, but i would think you could "toast" it some with heat to increase spine... Has anyone tried this?.... Brian

koan,
With the arrow being round, I don't think you will pick up much spine.

You can add a little weight to the nock end of the arrow and pick up some spine, but not much.

Quote from: PEARL DRUMS on April 22, 2014, 03:21:24 pm
Very nice stakes, or 45-50# arrows that are 26-27" long. Im 6' 1" and draw 27.5" if I squeeze my cheeks together. I shoot 28-28.5" bop arrows.

I'm with Pearl,  if I have some shafts on the weak side, I make them as short as possible.  I'm 6' 1" also and only draw about 27", and its true about hand size, shoe size and "draw length".. ::) ;)
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Don Case

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Re: Increasing spine?
« Reply #13 on: April 22, 2014, 08:47:09 pm »
I just tried toasting one and it changed the deflection from .700 to .600 which sounds good but the arrow bent a lot and didn't straighten when I heated the other side. I'll wait til it cools completely and then use more heat to try to straighten it. So it looks like it works but it's a lot less fuss to start with a stiffer arrow. I'll probably have an extra hour into it. Not that my time is worth much :D
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Offline Pat B

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Re: Increasing spine?
« Reply #14 on: April 22, 2014, 08:58:08 pm »
Don, heat the shaft while spinning it starting at one end and work down the shaft to the other end. Lay it on a flat surface to cool completely. You should still be able to make slight adjustments by hand after tempering.
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Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC
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