Primitive Archer
Main Discussion Area => Bows => Topic started by: Wooden Spring on August 09, 2015, 06:43:48 pm
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I'm glueing up a hard maple backed ipe bow. My goal is for another simple one similar to my recent hard maple backed white oak. That bow was a bit long at 70", it was 1.5" wide up to midlimb, then tapered to .5" nocks. It came in at around 45# @ 28".
OK, for my ipe glue-up, I want my hunting bow for black bear this year. I'm going back to 68" long for my 27" draw, but what width should I use for about a 55 to 60 pounds? My glue-up is currently 1.75" wide, but I doubt I'll need that whole width....
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Assuming the backing is super clean, and that it won't be the weak link (never used hard maple backing so can't help there)
The ipe you could basically make as narrow as you dare. I build a 68" BBI years ago for a friend and it was about 65# @28", 8" stiff handle, and just about 1.125-1.25" wide at the fades tapering to ~3/8" tips. I've heard stories of ipe bows being made more narrow than that too.
If you go too narrow you're problem will be in preventing limb twist when tillering. That's really gonna be you're limiting factor.
I think I glued in around 1-2" reflex and the bow ended up pipe straight once shot in.
The main thing is that the tips really should be dangerously thin and narrow to keep e weight down.
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I agree with Ben on the dimensions. Tomorrow I will be tillering out a white oak back ipe 62" long, 70#@26". Width is 1 1 /16 wide. You want the outer limb narrow but no so narrow that you loose lateral stability when it is braced. If you keep the working portion of the limb shorter ( stiff outer limbs, it will tolerate a little more width without handshock or loss of speed.
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Ipe is very strong in compression, so much so that it could, potentially, overpower the maple backing.
I'm not an ipe expert by any means but just going on density 1 1/8 of and inch at the handle tapering to 3/8 or less tips should be plenty, I might even suggest rounding the belly a little bit to bring ipe's insane compression strength into balance with maple's relatively strong tension strength. I've seen a #60 ipe self bow that was a mere 3/4 inch wide at the handle so that should say something about the woods qualities.
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Yeah x2 with ben on dimensions, ben hard maple is a great backer wood
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Ipe is very strong but it will fret if overstressed. I know from experience. ;)
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Ipe is very strong but it will fret if overstressed. I know from experience. ;)
It sure can!! Watch those naughty pin knots......I will not use any ipe that has a pin knot because it will fail there.
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If you decide to finish your bow at 1 1/4" wide, or more. Id suggest a very thin backing with very rounded edges, or you wont have any ipe left on the belly. I'd lean towards 1 1/8" max for your desired end product.
http://www.primitivearcher.com/smf/index.php/topic,47203.msg644724.html#msg644724
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If you decide to finish your bow at 1 1/4" wide, or more. Id suggest a very thin backing with very rounded edges, or you wont have any ipe left on the belly. I'd lean towards 1 1/8" max for your desired end product.
http://www.primitivearcher.com/smf/index.php/topic,47203.msg644724.html#msg644724
Awesome bow. Yeah that's pretty much the route I'm taking... Last night I marked and cut out the width. I'm leaving it just a tad wide, and I can always take off wood if it's too much. Here's where we are so far:
68" NTN (27-28" draw)
4" handle, 2" fades
1-1/8" wide limbs, parallel for 14", then taper for 16" to 3/8" nocks. It will have 3" long tip overlays of ipe.
I've never made a top nock like you showed - I've always used pin nocks at 1/2" wide, so this will be a bit of a different approach for me.
I have marked off to make the belly a consistent 5/8" thick, which usually places the bow at floor tiller, and I'll shape it on the tillering tree from there. I'll start the belly shaping tonight. Maybe then I'll have something worth a picture... Right now it just looks like a cane fishing pole with a 2" reflex.