Primitive Archer
Main Discussion Area => Bows => Topic started by: Siyah Later on April 30, 2016, 01:08:31 pm
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I'm starting out on my first selfbow (I've made three board bows to this point), and I wanted to ask for some advice. The stave I have is half of a roughly 4 inch diameter yellow birch tree, which I cut down, split, and debarked about 8 months ago. I realize that this probably isn't adequate drying time, so I was hoping to bring it floor tiller and then give it a month or two more to dry.
The stave veers off to one side a bit at one end, and has lots of knots at the other side. In order to get 66"-70" of length I'll have to use either the crooked end or the end with the knots. My inclination would be to avoid the knots, but I wanted a second opinion.
Also, I was thinking of doing a straight forward flatbow (correct me if that's the wrong term), 66"-70" in length, perhaps 2" (or maybe 1 3/4") wide out to mid limb and then tapering to 1/2" nocks, with a stiff handle. I'd like to get a 28" draw and hopefully around 40# of draw weight. Is this a good design for yellow birch, or would something else be better?
Here are a few pictures of the stave. Note that I've already done a bit of narrowing and cleaning up, it was originally a bit wider.
(https://www.dropbox.com/s/mprgvxbukiq7cw0/stave%20bow%20log%20pics.jpg?dl=1)
Note that the stave is flipped end to end from the first picture:
(https://www.dropbox.com/s/vaoyhzfyxzzbl0v/stave%20bow%20log%20pics-5.jpg?dl=1)
End with knots:
(https://www.dropbox.com/s/63u43gp4frifu1b/stave%20bow%20log%20pics-3.jpg?dl=1)
End with bend:
(https://www.dropbox.com/s/ijnshw5grtcfxxp/stave%20bow%20log%20pics-4.jpg?dl=1)
Thanks.
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My knowledge of working birch into a bow lands exactly halfway between diddly and squat. I just wanted to welcome you here and say that your username is one of the absolute best to ever show up in here!!!
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Thanks for the welcome. Glad you like the name; I just can't resist making puns.
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Thanks for the welcome. Glad you like the name; I just can't resist making puns.
They are always trying to "pun"ish me for my humor around here...be careful.
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My knowledge of birch is even less than JW but wanted to say welcome aboard , I dont think you would have much of a problem steaming out that laterale bend !
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Yellow Birch heat bends well. It also has a tendency to warp as it dries so be careful. The dimensions you posted would work well, just make sure you don't stress the wood too much as it can chrysal.
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Thanks for the advice. It does seem to have warped a bit as it dried, so maybe next time I'll tie them down. This one doesn't seem too bad, but it'll need to be bent about an inch to bring the string to center. It's also a little bit twisted. Today I took it down to two inches wide and about 3/4 of an inch thick. I suppose I'll give it a little while to finish drying now.
Would it be better to use steam or dry heat? It'd be nice and easy to use a heat gun, but if steam is better I could manage.
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Birch can be rather brittle. I would avoid knots at all costs. I would do no heat treatment until after the floor tiller. Never pull the bow more than your intended draw weight minus five pounds, to be safe. Go slow and post what you got after it bends several inches, please.
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The damn shame about Birch, is that it grows straight and fast. I've tried to make a couple bows out of the tress in my back lot, but they always break right when I think I have them tillered. If you're successful, let us know how you did it.
Welcome to the PA knowledge trust.
Tillstave.
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With my limited exsperience bending wood , for green wood you probably would be better off steam bending as oposed to dry heat , theres a great read on bending in TBB !
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Thanks for the tips. It sounds like I'm in for a bit of a challenge! I'll go really slow on this one and keep posting as I make progress.
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I brought the stave down to rough size and left it to dry for about a week, and now I've begun to tiller it. I've basically just floor tillered it at this point and it's bending quite a bit now so I thought I'd check in and post some progress (or should I say bowgress) shots. Now that the bow is pretty well down to dimensions, the string isn't off center by very much, maybe about half and inch, so I think I'll just leave it and avoid any heat bending.
(https://www.dropbox.com/s/4pi84v9oyab9pnt/Birch%20Bow%20early%20tiller-3.jpg?dl=1)
(https://www.dropbox.com/s/h5ayarkjafyvilc/Birch%20Bow%20early%20tiller.jpg?dl=1)
The tiller looks pretty good to me at this point, although it certainly has some room for improvement. The limb on the right in the picture is bending more but it has more natural deflex so maybe that's a good thing?
Any advice is welcome.
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So far so good IMHO.
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I've got it braced and bending a bit more. It's going pretty well so far; the bow hasn't take much set at all. It's pretty far from straight when looking from tip to tip, but the string lines up properly at the handle, so hopefully it will be okay.
(https://www.dropbox.com/s/h1l967afs4219uk/Tiller%20part%202-2.jpg?dl=1)
(https://www.dropbox.com/s/98mgw6ceusv26py/Tiller%20part%202.jpg?dl=1)
It seems a bit stiff at the very edge of the right fade, and the fade itself seems long compared to the left fade, so I'll try to shorten it up a bit.
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Looks like your on track Siyah...Shape that fade and go sloooow... ;) Keep us posted
Don
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Will do!
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I think I can tentatively call this bow a success. I tillered it to full draw today and took about 50 shots and had no issues. It ended up around 40# at 28", which I'm happy with. It's probably just my excitement but it seemed to shoot quite fast. It has some hand shock but it's not so bad considering that the tips are pretty wide. I'll put the finishing touches on it and post it in a new thread soon.
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Take some mass from the tips, whatever you can afford, and that will reduce your hand shock. Tiller is looking real nice.