Author Topic: Highly deflexed yew stave bow design choices  (Read 2295 times)

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Offline Strichev

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Highly deflexed yew stave bow design choices
« on: February 11, 2017, 05:16:07 am »
I have a highly deflexed  yew stave (the deflex is spread out rather evenly along its length) and I'm wondering what sort of a bow design would suit it most. It has somewhere around 5 inches of deflex. I'll provide pictures and exact measurements when I get the opportunity.

I can see two ways of approaching this matter;

I could go all Ötzi on it and remove the sapwood, go all heartwood while turning deflex into reflex. Still, I would end up with a weakened design with loads of reflex - I'm not sure that's a winning combination. Then again, for the target weight of around 60 pounds it could actually work. Maybe. If it's flat enough.

The other way would be using steam to set the handle further back and to sharply reflex the tips, leaving  the natural deflex in the working limb while getting decent string angle and tension.

Does anyone have a bow made from something similar? I guess it's hard to say anything without pictures, but it's really just a deflex yew stave. Length is not  a problem and it's totally free of any prop twist while being completely straight. At least string alignment shouldn't be a problem. As I've said, pictures coming soon.

mikekeswick

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Re: Highly deflexed yew stave bow design choices
« Reply #1 on: February 11, 2017, 05:36:17 am »
Why do you think turning it around would make it a weakened design? The wood doesn't care which way you bend it as long as the tension is taken care of. Trees bend in all directions in the wind :)
I would probably use it backwards and sinew back it.
Trying to steam deflex out wouldn't work. It would come back once bent.
Reflexed handles lead to earlier in the draw stack.
You could leave it as is and make some sharp recurves but it sounds like you have a bit too much deflex for that to work. You would want the tips 2 inches in front of the handle to get decent string tension.

Offline Strichev

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Re: Highly deflexed yew stave bow design choices
« Reply #2 on: February 11, 2017, 06:06:49 am »
I've read how it's less than optimal to have it turned around. I didn't consider sinew backing it. Now that you mention it it could be a fun project.

Offline Marc St Louis

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Re: Highly deflexed yew stave bow design choices
« Reply #3 on: February 11, 2017, 08:14:31 am »
I had one like that.  It had about 4 or 5 inches of deflex and several large knots.  Kept it around for a few years wondering what to do with it and then made a bow out of it a couple years ago.  I used dry heat to take out the deflex tempering the belly at the same time to set the shape and flipped the tips a bit to give it a few inches of reflex.  Worked well.  Made a nice ALB out of it that shoots quite well

Home of heat-treating, Corbeil, On.  Canada

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Offline DC

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Re: Highly deflexed yew stave bow design choices
« Reply #4 on: February 11, 2017, 12:54:19 pm »
http://www.primitivearcher.com/smf/index.php/topic,58404.msg808739.html#msg808739

This one had at least 5" of deflex. I steamed in long recurves and "locked" it with dry heat. It lost some of the recurve but I ended up with about an inch of reflex. It's a very nice ,fast bow. Don't know why I never posted it.

Offline wizardgoat

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Re: Highly deflexed yew stave bow design choices
« Reply #5 on: February 11, 2017, 01:11:48 pm »
deflexed yew staves make awesome recurves, I've made many

Offline DuBois

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Re: Highly deflexed yew stave bow design choices
« Reply #6 on: February 11, 2017, 01:13:35 pm »
I've got a yew stave that was straight when I got it and has taken on maybe 4" deflex on one end only. Also a lilac that is a ( in deflex, so got my eye on this.
Might be my first backwards sinew bow someday when I feel ready for it.
DC do you still have the finished bow? Would love to see it all done.

Offline DC

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Re: Highly deflexed yew stave bow design choices
« Reply #7 on: February 11, 2017, 01:15:39 pm »
Yes I do. I'll post it after the snow melts, again.