Primitive Archer
Main Discussion Area => Bows => Topic started by: Matt S. on September 14, 2011, 01:00:34 pm
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I'm working on my first backed bow and am excited to be trying something new.
Here's what I have so far:
Hickory backed Maple (board, unknown species, denser and "redder" than 2 previous failed (chrysalled) Maple bows).
Length: (t-t) 64", (n-n) 62-63"
Desired Draw: 50-60#+ @ 28"
Profile: ~1.5" wide out to mid limbs, then taper to 3/8" tips.
Bendy handle
~2.5" Perry Reflex
Tempered Belly
So far I've done some rough shaping and glued the boards up into ~2.5" of Perry reflex. BEFORE gluing up, I heat tempered the belly (but left flat) in the hopes of increasing the Maple's compression strength.
Currently, the hickory backing is a hair over 1/8" thick. I plan on sanding it down to a hair under 1/8" thick.
My Questions
My biggest concern is the Hickory over powering the Maple.
1. Should I trap the back?
2. How thick should the backing be?
3. Will the heat tempering on the belly help balance the compression vs tensions strength?
4. I have no doubt that the Hickory can stand up to a 60# design, but I'm not sure about the Maple. Would you tiller this out to a full compass bend so all the limb is working or do you think I could get away with non-working stiff tips? (Like my Red Oak bow here http://www.primitivearcher.com/smf/index.php/topic,27282.msg364898.html#msg364898 (http://www.primitivearcher.com/smf/index.php/topic,27282.msg364898.html#msg364898) with "Eiffel-tower" taper)
5. And finally, would it be wise to use the Mass Formula to determine goal draw weight? I would really like around 60# but I have no experience with backed or reflexed bows so I'm out of my element.
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I have several other questions but this post is getting long winded as-is so I'll just leave this out there so the wise and experienced can direct me towards bow Enlightenment :D
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I would go wider, maybe 1 3/4" and a touch longer. Hickory is much stronger than maple so Im thinking the backer should be no more than .100" thick. Heat tempering will help the belly hang with the hickory.
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Both pieces of wood are from 1x2 boards, so I'm stuck at 1.5" wide and 64" t-t long tops. If you think 60# would be too much I can always go for a lower weight, say maybe a 50#er. If it were made well and efficient, I would think a 50# with reflex would still be a real arrow screamer.
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My reflexed bows are my fastest of the herd, even at much lighter draw weights. Low 50's would work great at 1 1/2" wide. Maybe try to keep the width out towards the tips a little farther than normal and leave that maple belly dead flat with slight radii on the edges.
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I'm sure it would hold up if you had kept the boards longer.
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I'm sure it would hold up if you had kept the boards longer.
True, but this was a case of "using what I had." The Hickory board had a giant bow-killing knot and I cut a piece off the Maple board for another project. Since the two boards were the same length I decided to go ahead and try a backed bow.
I ripped the Maple board on the table saw and have a 3/16" backer strip from it and I still have 2 backer strips from the Hickory board, so I'll definitely be doing more backed bows in the future ;)
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Make the handle carry a load and that length will be fine and dandy. Or, add some tip overlays and you can generally gain a 1/2" of length each way by filing the grooves in creatively. Lots of options Matt.
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Make the handle carry a load and that length will be fine and dandy. Or, add some tip overlays and you can generally gain a 1/2" of length each way by filing the grooves in creatively. Lots of options Matt.
It'll definitely bend through the handle. I haven't decided yet on tip overlays but that is a good option. I really just want to gain some experience with this since it's my first backed bow and first Perry-reflexed. Most of my experience thus far is with red oak selfbows.