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Main Boards => The Bowyer's Bench => Topic started by: wildbill001 on June 02, 2011, 06:46:00 PM

Title: pyramid design and draw-weight question
Post by: wildbill001 on June 02, 2011, 06:46:00 PM
I'm confused, which is easily done these days.  As per another post, I'm attempting my first board-bow build.  Red-Oak, 67" ntn and would like a draw weight in the 35-40# range @ 27".  Can't pull much more than that due to joint/shoulder  issues.

What's confusing to me as I work on this and research is how exactly is the draw-weight controlled on a pyramid style bow?  Several places on the net indicate it is controlled by limb thickness/taper.  Other places/resources say the thickness of the limbs should be constant but the width of the limbs control the draw weight.

I dunno who to believe.

Help an ol codger out, please    :pray:

TIA

Bill
Title: Re: pyramid design and draw-weight question
Post by: Philthy on June 02, 2011, 07:03:00 PM
Red Oak doesnt like narrow limbs like you can get away with on some other woods (like Osage).  You might narrow the width a little bit but not much.  The strength of this design is in the wide limb width.  I would bring the draw weight down by thinning the limb thickness.
Title: Re: pyramid design and draw-weight question
Post by: bigcountry on June 02, 2011, 07:47:00 PM
The one pure pyramid osage I did build, was consistent thickness, all the way to the tips.  

Actually pretty easy to build.  But I seem to miss wieght on pyramid osage styles.  I like parrelel up about 10-12" from the fades.
Title: Re: pyramid design and draw-weight question
Post by: Philthy on June 02, 2011, 08:01:00 PM
Typically the thickness on a pyramid is very consistent.  The tiller on a pyramid design is also more circular than on a woodlands style
Title: Re: pyramid design and draw-weight question
Post by: John Scifres on June 03, 2011, 12:21:00 PM
Thin, narrow, or taper?  And the answer is: You can do any of the above to adjust weight or tiller.  

But a pyramid style's biggest advantage is that it is really easy to build if designed properly.  Get a thickness that will make the weight and then carefully cut it out and you are mostly done.  If it's too heavy, make it, or the next one, thinner if you are using a compression weak wood like red oak.

Remember, thick/thin is measured back to belly.  Wide/narrow is measured side to side.

Thickness tapering just makes it more complicated.
Title: Re: pyramid design and draw-weight question
Post by: wildbill001 on June 03, 2011, 10:59:00 PM
Okey dokey then I guess I just keep doing what I'm doing (i.e., slowly removing thickness) and not worry about tapering.

THANKS!

Bill