Author Topic: Too much curve?  (Read 1772 times)

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Offline ShorterJ

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Too much curve?
« on: July 10, 2021, 07:09:44 pm »
Hey everybody, I’ve got a hickory stave roughed out that has a significant curve the whole length (66” ntn).  Is this too much curve?  Could this cause propeller twist after it’s strung up and sets?  The way the tips align means the string would be in line with the edge of the handle.  If I flex the stave as if I were going to string it it tries to twist in my hand.  Any input is greatly appreciated.

Offline RyanY

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Re: Too much curve?
« Reply #1 on: July 10, 2021, 07:39:33 pm »
That’s very mild. Should be easily corrected with a bit of dry heat.

Offline Pat B

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Re: Too much curve?
« Reply #2 on: July 10, 2021, 11:57:57 pm »
I agree with Ryan. A 2x4(or work bench), a few clamps and a heat gun will get it straight.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Don W

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Re: Too much curve?
« Reply #3 on: July 11, 2021, 08:29:40 am »
The statements suggest a fix but doesn't answer the question. Ryan Gill has written several articles suggesting that leaving something like this allows a much broader spine of arrows. Personally I'd leave it and try it. It can be fixed later if needed, unless you prefer the symmetrical look. I did it with a maple stave and it's shooting well.
Don

Offline scp

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Re: Too much curve?
« Reply #4 on: July 11, 2021, 12:13:01 pm »
Why would anyone turn the gift of natural center shot into the problem of forcing manufactured bow aesthetics on a natural material bow?

Offline Pat B

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Re: Too much curve?
« Reply #5 on: July 11, 2021, 01:25:13 pm »
You won't really know if it is too much bend until you get to low brace. Start tillering the stave until you get to brace, with both limbs bending evenly and together then you can make the judgement whether or not to straighten the stave.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Don W

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Re: Too much curve?
« Reply #6 on: July 11, 2021, 02:03:23 pm »
It could be a good time to play around with side nocks as well, if you're into experimenting.
Don

Offline bentstick54

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Re: Too much curve?
« Reply #7 on: July 11, 2021, 09:16:12 pm »
My suggestion would be to straighten it due to that fact that it tries to twist in your hand now. Nothing wrong with making a crooked stick straight.

Offline Morgan

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Re: Too much curve?
« Reply #8 on: July 11, 2021, 10:12:42 pm »
Like pat said, tiller to brace and then decide. I have a couple that have some side bow to them and like them a lot, I’ve also taken some side bow out of others. If it twists and is unruly, then you ought to get it straight. For certain, things will be some different when you get it bending. It twists in your hand now cause that’s all it can do. If I had to give hard and fast straighten or not advice as it stands, I would say stretch a string on it, if the string bisects outside of where the pass will be by more than just a hair, I’d straighten a bit. That is if you can’t bring the string in some with nick placement like don suggested. If you can get it to bend with that side bow in it, my guess is that you won’t be unhappy with the way it shoots.

Offline Morgan

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Re: Too much curve?
« Reply #9 on: July 11, 2021, 10:22:02 pm »
Hope you can see it in this bow. It has been shot more than any other bow I’ve made. Couldn’t even begin to guess a count on it, but it’s a lot. No sign of degrading in any way which is something I was worried about while making it although I’m not sure why. If I have a little time to shoot in the back, 8 times of 10 I string that one. Just a smooth forgiving bow, some of the forgiving I think comes from where the string lies.

Offline ShorterJ

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Re: Too much curve?
« Reply #10 on: July 12, 2021, 12:59:14 am »
Thank you all for the input.  I’ll bring it to a brace and if the string isn’t too far out and the limbs don’t twist then I’ll finish it out.  Originally I picked this stave because it would be close to center shot like scp and don said, but as I roughed it out I started to wonder if it was too much.  If so I’ll try playing around with the nocks like don mentioned.  I’m assuming you just cut the nock deeper on the arrow pass side or side that the string favors?

Offline Del the cat

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Re: Too much curve?
« Reply #11 on: July 12, 2021, 09:30:00 am »
Yes! Too much curve!
A bow isn't held rigid at the grip... as it is drawn the string tension will automatically line up the grip ( the centre of hand of pressure) and the tips. If these are out in line the bow will try to twist to line them up.
A natural "centre shot" must still fulfil this requirement... a simply curved bow, won't do the job., a tiny bit of curve is ok, but it is more normal to have a slight S shape at the grip so the bow doesn't twist grip and tips still line up.
Use heat or steam to get the limbs in line, you can then relieve the arrow pass if you like.
Del
BTW. None of this is anything to do with propeller twist... it's just about the bow twisting in your hand.
Health warning, these posts may contain traces of nut.

Offline scp

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Re: Too much curve?
« Reply #12 on: July 12, 2021, 01:20:29 pm »
How tiny? If the braced string goes outside the handle, it needs to be brought back inside. There are many ways of doing that. Bending unbending parts sideways, after floor tillering, will be enough. No need to use heat to bend the working limb. Of course there will be exceptions for character bows.

Offline Del the cat

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Re: Too much curve?
« Reply #13 on: July 12, 2021, 02:22:24 pm »
I s'pose I should add that if Bracing it twists the grip slightly (as it is likely to) then the plane of limbs and string could be considered a frame of reference. If as the bow is drawn everything stays on that plane then it's all good. The grip and arrow pass would need to be aligned to that plane.
What that means in practice is the grip lines up with how the bow draw, not necessarily at 90 degrees to the back.
Dunno if that makes sense of is helpful... s'pose it can be summed up by saying pull it and shoot it ,but don't try to force it to draw with the back square else it will just torque in your hand.
The problem with allowing this to happen is that it can become worse over time, I once saw a Yew longbow being shot that was bending in such a way that the sapwood was almost on the side of the bow rather than the back! :o
Del
« Last Edit: July 12, 2021, 03:19:38 pm by Del the cat »
Health warning, these posts may contain traces of nut.

Offline Don W

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Re: Too much curve?
« Reply #14 on: July 12, 2021, 03:54:57 pm »
I suggest Ryan Gill's article in April/may issue of this year's PA. It talks about this in detail.
Don