Author Topic: Limb thickness question.  (Read 1964 times)

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Offline autologus

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Limb thickness question.
« on: November 25, 2012, 04:10:11 pm »
I am ready to cut out the limb thickness on a bow I'm working on and was wondering how thick to start. It is white oak quarter sawn 2 inches wide with 18 inches of working limb each side and 13 inch levers.

I would like it to come in at about 60 pounds at 30 inches of draw. It has a 10 inch non working handle that includes the fades.

Grady
Proud Hillbilly from Arkansas.

Offline Pat B

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Re: Limb thickness question.
« Reply #1 on: November 25, 2012, 04:24:51 pm »
Grady, How long is the bow?   I assume that you are using a 3/4" thick board for your bow.   I like to start thick and rasp down until the limbs begin to bend at floor tiller. With tree staves I usually reduce the limbs to 3/4" and rasp down from there.  A lot less chance of taking too much off at one time.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline DarkSoul

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Re: Limb thickness question.
« Reply #2 on: November 25, 2012, 06:02:54 pm »
5/8" will get you close. Don't slip with the saw. Leave the levers at least 3/4".
"Sonuit contento nervus ab arcu."
Ovid, Metamorphoses VI-286

Offline autologus

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Re: Limb thickness question.
« Reply #3 on: November 25, 2012, 06:31:04 pm »
That is what I was guessing dark and went with 5/8 thick with 3/4 thick levers.  It does seem to be about right on floor tiller.  I have it heat treated and ready to tiller it.

Grady
Proud Hillbilly from Arkansas.

Offline lesken2011

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Re: Limb thickness question.
« Reply #4 on: November 26, 2012, 10:16:06 am »
Be careful around the handle fades and make sure you take enough wood off the lever fades. My first adult lever bow developed some compression fractures near the handle after shooting it in. I thought at first that it was a poor design, but realized later that there was more stress near the handle than the fade. With limited bending parts of the limb, the whole part should have equal bend. For me, it is difficult to see with my eyes compared to a standard circular tiller.
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Kenny from Mississippi, USA

Offline autologus

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Re: Limb thickness question.
« Reply #5 on: November 26, 2012, 10:22:58 am »
I have smooth transition on the handle fades and will work the lever fades a bit more to get them a little more smooth.  I will work this one very slowly, I want it to turn out to be a nice bow for a Christmas gift.  I am making it for a young man at church that is about 6ft 230# at 13.  It has to be very strong and durable.

Grady
Proud Hillbilly from Arkansas.

blackhawk

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Re: Limb thickness question.
« Reply #6 on: November 26, 2012, 10:42:00 am »
That's really pushing it spec wise for what you are intending to do IMHO. You better tiller carefully from the first pull till the last and get your tiller dead nuts because that is borderline almost underbuilt,and if you want it to be durable then you better be careful bending it. If not that has a good chance of fretting and eventually breaking or outright break. Its just a fair warning and I'm not saying it will happen,but you are taking chances if not done right. IMO I would've chose a different design with that board to reach the specs you want,and especially for such a big young man which hasn't gotten used to his large frame yet. Just my two cents of wisdom.

Offline George Tsoukalas

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Re: Limb thickness question.
« Reply #7 on: November 26, 2012, 10:50:54 am »
Caution. When working with 1/4 sawn boards the grain must be completely straight from tip to tip, unlike the other 2 cuts which tolerate a few run outs, or your stave may break. Jawge
Set Happens!
If you ain't breakin' you ain't makin!

Offline autologus

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Re: Limb thickness question.
« Reply #8 on: November 26, 2012, 12:21:19 pm »
I will be very careful and tiller slowly to get it right.  If it comes in under weight that is OK I just want to make sure that I get it tillered to that draw length because you know how young boys can be and want to test their manhood.  I may still back it with linen just to be on the safe side but I will probably make that decision after tillering to see how it is.  I appreciate the words of wisdom and caution they will all be heeded.

Grady
Proud Hillbilly from Arkansas.