Author Topic: Backing a wide limb with narrow boo?  (Read 8064 times)

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Offline Radon

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Backing a wide limb with narrow boo?
« on: March 28, 2009, 06:41:14 am »
Hi all

I have a question on bamboo backing:
I want to build a "Holmegaard style" bow, juniper with a boo backing and a pressure resistant facing at the bending section.
Now the only bamboo I have available is about 1 3/4" wide.
The limbs should be at least 2" at the widest point. Any suggestions how to do it?

a) Just glue the boo on the wider wood and leave the outer parts of the limbs unbacked ( -'==='- )
b) Two strips of bamboo ( '=='==' )
c) Three Strips ( '='=='=' )
d) split the bamboo in the middle, bend it wider and fill the gap with a alternate backing (sinew?) ( '=='-'==' )
e) leave it altogather because all the above ideas are crap
f) a better suggestion

Thanks a lot
Radon
« Last Edit: March 28, 2009, 10:37:52 am by Radon »
Dresden - Germany

Offline Pat B

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Re: Backing a wide limb with narrow boo?
« Reply #1 on: March 28, 2009, 11:16:56 am »
You can easily make a trapezoidal cross section with the narrower boo back and wider belly. For Juniper this would probably be the preferable method anyway as Juniper is weaker in compression. I only hope the boo isn't too strong for the Juniper belly. How long will your bow be?
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Radon

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Re: Backing a wide limb with narrow boo?
« Reply #2 on: March 28, 2009, 12:31:13 pm »
Actually, this bow will be purely experimental.
Bow length should be something around 62", 50+x#@28"
max. 1/2 of the limb bending.
Of course the Juniper won't take that. Therefore the bending parts will receive buffalo horn as facing.

Radon
Dresden - Germany

Offline matte

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Re: Backing a wide limb with narrow boo?
« Reply #3 on: April 16, 2009, 12:06:57 pm »
the pearson bow company use to back some of their bows with two strips of bamboo side by side length ways.This was during the late forties early fifties.

Offline bobnewboy

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Re: Backing a wide limb with narrow boo?
« Reply #4 on: April 20, 2009, 09:24:01 am »
I think that Pat is right about 'trapping' the back.  If you keep the same dimensions as you've written you'll only have .25" of belly material each side of the boo in any case.  Using buff horn as a belly facing will be really interesting, and I'll be following this one with great interest (normally I'm a bit of a lurker in any case  8) ).  If it all comes together well I think that the bow will be a real flyer.

//Bob
"The Englishman takes great pride in his liberty. He values this gift more than all the joys of life, and would sacrifice everything to retain it. The populace would have you understand there is no country in the world where such perfect freedom can be enjoyed, as in England!" Frenchman, London 1719

Offline Talonzz

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Re: Backing a wide limb with narrow boo?
« Reply #5 on: May 07, 2009, 01:31:22 pm »
In the first chapter of TBB2 around page 40 maybe... They talk about backing a bow with multiple strips of bamboo side by side...  Made out of window blinds no less.
Nobody Ever got Anywhere by Being Content...
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