Primitive Archer
Main Discussion Area => Bows => Topic started by: NJWoodsman on October 14, 2010, 12:58:32 pm
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I've been tillering a shagbark hickory selfbow. The dimensions are 66" nock-to-nock, using the layout of the osage flatbow in TBB vol 1., though I made it slightly wider.
I was shooting for 50# @ 28", and with a tiller string I never pulled it beyond 40 (using a cheap fish scale). Though I was careful and not aggressive, I seem to have overdone it. When I braced it and pulled it back the first time, it obviously was well below 50#, more like 40. And, a propeller twist is much more evident though I've tried a heat gun & tillering to minimize it.
I was think of shortening it an inch to raise the draw weight- would this be risky with this design by bending the limbs too much? I tried that with a red oak board bow once and it lasted 20 shots.
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You can definitely get away with shorting it for a 28" draw. You could also try heat treating in some reflex if you haven't already done this.... Sounds like you were on the long string to long. You need to get the bow braced as soon as you can or you'll take off to much every time. The scale will not read correctly with a long string.
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Howdy, Things I've done to raise draw weight: Pike the limbs, steam in recurves, heat treat the belly and add reflex, put on a substantial backing ( like sinew or another layer of hickory.) Not that I've ever over shot my planned draw weight, mind you. I can think of one bow that I did all of these things and raised a 25# draw weight up to 40#. As occasionally is said on this forum, "Fix it 'til it breaks." Ron
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Hickory's tough. You can do any of these things and if you're careful it'll hold fast and last :).
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I wouldn't shorten it. I'd make another. :) Jawge
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Should have listened to Jawge. I heated it and worked out most of the remaining twist. Then I cut in new nocks 1" closer- each, and braced it. It was a bit lop-sided, but I fixed that, too. Pulled it back a few times, not quite to full draw, but it was up to the weight I was looking for. So I pull to full draw, feel it stack- and OH SNAP! Top limb blew at the top third.
I have a couple more staves from the same tree, but for now I put my tools away. I'm going hunting, when it gets too cold & dark this winter maybe I'll try a Holmegaard instead.
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Build a little campfire from the scraps, brew a cuppa strong coffee while you are drawing out the dimensions of the next bow, drink up, and get back to work!
Been there and done that so often there is a path worn in the lawn!
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That's ok, NJ. Make another one. :) BTW you would have gained around 5# loosing an inch from both limbs. What you gain in weight does not necessarily translate to an increase in cast or fps because you may also add some set due to the shorter length. For the record I long string tiller out to 10 inches of string movement and almost always make weight. It's not ditching the long string it's the no. of bows under your belt that help you make weight. That's also one of the reasons I suggested that you just make another. :) Jawge
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How soon after you heat treated the bow did you brace and pull it? After heat treating I always give the bow a few days to rehydrate before stressing it.
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These days i haven't even been using the long string. I pretty much floor tiller it down to brace and THEN get the scale involved. Paying attention to the evenness of the curve is essential at the beginning, more so than the draw weight. Sounds like you did a bunch of work and learned a lot so yeah, make a fire, brew some coffee, make a new bow, as a wise man said above.
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so yeah, make a fire, brew some coffee, make a new bow, as a wise man said above.
Wise guy, wundabred, not wise man. Get it right, sheesh!
NJ, think of it this way. You just made a nice bow for a younger person or someone with a compromised shoulder, they just don't know it yet. And since you were kind enough to build a bow for someone you may not have yet met, it is fair that you make one for yourself. What a perfect act of kindness on your part.
Maybe I should get a job in the gub'ment as a Spin Doctor?