Author Topic: Failure-advice needed (Success now)  (Read 9607 times)

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Offline DC

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Failure-advice needed (Success now)
« on: January 22, 2018, 11:45:04 am »
This is my attempt at copying one of Marc's bows. I made one out of OS and it worked pretty well so I decided to make a Boo backed Yew one. I spliced in about the same amount of deflex that Marc did(I eyeballed the picture) Everything in the build went well and I glued the backing on after I had tillered it out to 30#@20. The limbs were about 9/16 tapering to 1/2 thick and 1 1/4 tapering to 3/4 wide at the start of the recurve, then tapered to 1/2. The boo was about .20 tapering to .10, in hindsite maybe a bit thick. I pulled some reflex into it at glueup. After the glueup it was like an iron rod. I could floor tiller it about a half inch. It had 3 1/4" of reflex. I figured if that was too much I could cut a bit off the tips. I went ahead tillering and all was well. It gained reflex as I tillered it and went as high as 3 7/8" before it levelled off. I had to do a minor heat correction to line up the string(twist the limb a touch) after I got it to low brace and then it was fine even with the big hooks. I got it to 40#@ 18.5 and then it started to go south. It developed a tiny hinge and I evened that out. Now I was close to done. Then it was like it decided to take a bunch of set all at once. Within a couple or three pulls it was down to 30# or so at 25" or so. I took it off the tree and now the reflex is 2 7/8". The Yew thickness is now 3/8" tapering to 1/4". I don't see any chrysalling.  I've made 3 other BooYews and they worked great but they are all skinny bows. I left this one wider so it might not twist and throw the string. Maybe it didn't leave enough Yew. I've got a couple of ideas for rebuilding it(belly lam) or I could strip off the Boo and start over.  What I'm wondering about is whether this design is too much for Yew? Any thoughts or ideas would really be appreciated. Thanks
PS The pictures are as it is now. It had more reflex in the limbs before
« Last Edit: January 28, 2018, 12:27:23 pm by DC »

Offline vinemaplebows

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Re: Failure-advice needed
« Reply #1 on: January 22, 2018, 11:51:57 am »
From what I can tell Most of Marcs bows are 2-piece spliced, and this gives him the ability to deflex the handle as much as he wants (within reason) Get more deflex in the handle area, and you may have more success.
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Offline bjrogg

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Re: Failure-advice needed
« Reply #2 on: January 22, 2018, 11:53:03 am »
DC my advice for failure is just to try new things it's bound to happen.lol
Seriously though I'm afraid I can't give much advice on your boo backed yew. My very uneducated guess would be maybe boo was to thick but you'd know better than me.
Bjrogg
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Offline JWMALONE

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Re: Failure-advice needed
« Reply #3 on: January 22, 2018, 11:57:26 am »
That's out of my league DC, but I'm buying the first chalk board I can find. That's an awesome idea, room for notes and everything.
Red Oak its the gateway wood!

Offline DC

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Re: Failure-advice needed
« Reply #4 on: January 22, 2018, 12:02:26 pm »
This one is two piece spliced and I went to great pains to copy the amount of deflex that Marc used. For some reason it doesn't show in the picture. This pic shows it better.

Offline BowEd

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Re: Failure-advice needed
« Reply #5 on: January 22, 2018, 12:03:30 pm »
DC...Sounds like you wanted more draw weight??? and you removed too much wood adjusting to your hinge.I would'nt be disappointed though and would'nt call it a complete failure.I don't see where it says the length though too.
It's fun watching that reflex increase while tillering,and from the start your still only looking at 3/8" set from 3 1/4" to 2 7/8".
BowEd
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Ed

Offline DC

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Re: Failure-advice needed
« Reply #6 on: January 22, 2018, 12:10:51 pm »
It's 58" measured directly and 64" if you follow the curves. About 21-22" working limb. I just measured the OS one and it has 25" or so working limb. Maybe that's it.

Offline Jim Davis

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Re: Failure-advice needed
« Reply #7 on: January 22, 2018, 12:32:23 pm »
This doesn't help
Jim Davis

Kentucky--formerly Maine

Offline DC

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Re: Failure-advice needed
« Reply #8 on: January 22, 2018, 12:43:27 pm »
This doesn't help
The picture was taken after everything went west. I haven't attempted to correct it yet. You could almost watch as different sections gave up. That was the last part. I had it pulled and the bow kind of jerked and there was a new bend.

Offline Marc St Louis

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Re: Failure-advice needed
« Reply #9 on: January 22, 2018, 01:50:07 pm »
This one is two piece spliced and I went to great pains to copy the amount of deflex that Marc used. For some reason it doesn't show in the picture. This pic shows it better.

Maybe you were trying too hard?  :D
Home of heat-treating, Corbeil, On.  Canada

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Offline PatM

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Re: Failure-advice needed
« Reply #10 on: January 22, 2018, 01:54:49 pm »
Marc uses less recurve and more reflex in the actual limbs.   Just using where the tips are relative to the back is a poor reflection of what's going on with the limbs when you add big hooks.

Offline DC

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Re: Failure-advice needed
« Reply #11 on: January 22, 2018, 02:41:42 pm »
There was originally more reflex in the limbs and I have real problems getting that tight a recurve. I was planning on shortening the tips but when the string stayed on I thought,"What the hey."
I braced it this morning and gave it a pull, it's 30#@27 and the limb that Jim pointed out is way weak. I think what I'll do is reduce the Yew thickness to around an eighth and glue on a new belly, in essence making a tri-lam. I'll try to reduce and tighten up the recurves while I'm at it. That will lengthen the working limb too. Maybe shorten the handle a bit. I could strip off the boo and start again(I'm short of Boo) but I think it will be the same amount of work either way.

Offline DC

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Re: Failure-advice needed
« Reply #12 on: January 22, 2018, 03:30:26 pm »
This one is two piece spliced and I went to great pains to copy the amount of deflex that Marc used. For some reason it doesn't show in the picture. This pic shows it better.

Maybe you were trying too hard?  :D

Too much deflex???

Offline pnwarcher

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Re: Failure-advice needed
« Reply #13 on: January 22, 2018, 03:35:31 pm »
Seems to me the real lesson here is that plain old yew just can't quite compete with ocean spray  ;)

Offline Marc St Louis

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Re: Failure-advice needed
« Reply #14 on: January 22, 2018, 03:58:15 pm »
This one is two piece spliced and I went to great pains to copy the amount of deflex that Marc used. For some reason it doesn't show in the picture. This pic shows it better.

Maybe you were trying too hard?  :D

Too much deflex???

No not that.  If you look on the left under my name it says number of posts and then something under that.  That is what you should keep in mind  :)
Home of heat-treating, Corbeil, On.  Canada

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