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Main Boards => The Bowyer's Bench => Topic started by: ProArcher on July 17, 2009, 09:29:00 AM
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:banghead: I want to try a lam bow.
I have walnut 1 ¾ x 4/4 x 70
I have cherry 1 ¾ x4/4 x 70
I have curly maple 1 ¾ x 4/4 x 85
I have Purple Heart 1 ¾ x 7/8 x 36
I have Bocote 1 ¾ x 4/4 x 38
The walnut has the best end grain. How do I need to cut, plane, and taper. I would like to get between 50# and 60#. How many pieces do I need for each stack? :confused:
I have read so many o/f the post here that my neck is killing me from tilting my head back to look through my bottom lens of my glasses.
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For a trilam bow the cherry or the walnut will work well as a core. The bocote should work fine for the belly but you will need hickory, boo or maple(not curly) for the backing.
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Thanks Pat
I was begining to wonder if I had ticked everyone off in here.
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Is this a fiberglass bow, ProArcher?
Otherwise, Pat said it right. Predicting weight on wood lam bows is tough. I just finished an elm sapling deflex recurve and a boo backed black locust deflex recurve. The first is nearly 5/8" thick, and the second is under 1/2" thick and they pull about the same...
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Hi Springbuck thanks for the reply.
at this point it is only wood. But I am not opposed to getting glass and going that rout. I did a red oak with bamboo back and belly, but was unable to get the target weight. So that is why I ask the question about cutting and tapering. I would love to do a takedown. As my buddy wants me to go to Texas in January to hunt. I just finished gluing up the handle, but have done nothing else. I would appreciate any help and advise. I have the Bingham Project DVD and have watched it about 10 times so far. My buddy has it now watching it.
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Pro Archer, While I am not an expert, I think I might point you in a direction further along the path. My experience is with building glass lamb bows. Binghams catalog in the back has a limb stack thickness chart for their bows. For example a 60 " take down recurve which is 1 3/4 inches wide for 50lbs draw weight should be .241 inches thick about one inch in from the thickest end. A similar bow with 2" wide limbs at 50 lbs would be .234 inches thick. This is a combination of all the wood and glass in the stack. (normally 2 glass, one back and one belly, and one parallel lamb and one tapered lamb)
For instance if the glass were .05 inches each that would leave .134 inches for the remaining two wood lambs. The tapered lamb either a .001 per running inch or .002 per running inch allows the limbs to bend evenly from the fades to the tips.
For me I have been buying the limb lamination sets (tapers and parallels plus the glass) to get me close to my target weights. (no major screw ups and loss of material which translates to expense) As the learning curve decreases I may try and grind a few lambs myself.
Best Regards and good luck, Also it would be my hope one of the more experienced guys would chime in here with more info.
Mike
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Thanks Mike I will check out the chart
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The fiberglass stack chart will be off for a wood bow, but really good for a fiberglass bow.
Dimensions are very different for glass and wood bows.
None of what you have makes a great backing, that I know of. If the grain really is straight on the walnut, you might get a board bow out of it as is. Otherwise, the bocote is your best compression wood, assuming straightish grain. The cherry is light but compression strong for it's weight. Walnut is heavier than cherry, but pretty good in compression.
See if you can round up saome white oak or maple for a backing and start with a 70" bow, 1/8" backing, 1/2" core of whatever you choose, glue up with mild reflex and SLOWLY scrape out the bow you want. Ask more questions as they come up.
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Thanks again Springbuck
I don't think questions will be scarce. This will be number 3 I’m definitely in the learning curve.
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Saturday I did a little work on the wood for my lam-bow.
This is cherry (on the left) walnut both planed to 1/4"
(http://i704.photobucket.com/albums/ww42/ProArcher/cherry_walnut_edge.jpg)
These are 1 1/2 wide no taper
(http://i704.photobucket.com/albums/ww42/ProArcher/cherry_walnut.jpg)
Two choices of handles
Walnut with Purple Heart and curly maple
(http://i704.photobucket.com/albums/ww42/ProArcher/Purpleheart_handle.jpg)
(http://i704.photobucket.com/albums/ww42/ProArcher/Purpleheart.jpg)
Or cherry & walnut
(http://i704.photobucket.com/albums/ww42/ProArcher/cherry_walnut_handle.jpg)
Any thoughts on the above.
I'm leaning towards clear glass over the walnut then add the cherry and belly it with Bocote 1/8" thick