Primitive Archer
Main Discussion Area => Bows => Topic started by: Kviljo on March 05, 2010, 06:34:49 pm
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This is my first real reflex/deflex, or rather it was.
It was 45# @ 27", and was shooting like no other 45-pound bow I have made to date. It died when I was about to say "done" just after taking the pictures.
The air is very dry right now, and it didn't loose much reflex at all. I tried to see where it lost relfex along the limbs while tillering it, but I do admit it is not easy with this design. It did break 2/3 in from the upper tip, but I can not find any flaw either in the glue lines or in the wood. - so I guess I was simply demanding too much bend out of that area. It should have been bending more in the outer part of the limbs.
As long as there is something to learn, it's all good.
(http://kviljo.no/bue/rd/3.jpg)
(http://kviljo.no/bue/rd/4.jpg)
(http://kviljo.no/bue/rd/5.jpg)
(http://kviljo.no/bue/rd/1.jpg)
(http://kviljo.no/bue/rd/2.jpg)
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What a shame, I love the clean simple uncluttered lines of the grip.
Better luck next time...it's all hard won experience.
Del
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well it was pretty anyhow... :) Hope you keep the next one together! :) Beautiful finish work
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I hate breaking bows, especially finished ones, but it goes with the territory. Nice job (up until the breaking part :P). Maybe too much bending at the fades ???
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Nice style but it looks like all the bend concentrated in the fades.
VB
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Uhh, too bad! - What wood was it??
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Ash, beech, cherry and walnut.
I'll start on a new R/D soon. Quite interesting design.
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Sorry to hear it didn't last.
I like what you did with the grip.
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Yes the grip looks pretty awesome. it looks like you overlayed the a cordage wrap with wood? am i lookin right?? How does that work?
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That's about right, Aries. I wrapped the grip with cordage and soaked it with glue. Then I filed the back and belly flat to be able to glue the extra pieces of walnut onto it. I think I might re-use the grip on the next one.
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bummer, it happens
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Your bow looked real good Kvilo. I've seen super dry air take out plenty of dependable bows. It can be such a fine line between a bow lasting forever and one blowing on the tree.
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Cool looking bow! 8) ...and I agree the R/D design isn't an easy task achieving proper tiller but I think you nailed it. 8) Where was the failure, in the wood or a glue joint?
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It broke about 2/3 in from the right limb. The glue line between the beech and the cherry did fail in the break, but I think the backing went first. I broke the other limb on purpose, and it snapped quite easily. On that limb, the glue line did not fail. The backing was quatersawn ash with no real flaws, and should be pretty safe so I'm a little puzzeled by it.
I think perhaps it was a combination of the low humidity and the choice of woods that led to the breakage. Ash is usually stiffer than beech, so the beech just under the ash backing might have put extra stress onto the ash. It should probably also have been bending more in the outer 1/3.
Perhaps? Any expert tips on the R/D-design is very much appreciated :)
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I personally have a hard time finding proper tiller with a R/D bow so I've only made a few. I've never used ash as a backing either but I know others have. Hickory or elm are two other options for backing if you have them available.
Anyway, cool bow. Looking forward to your next one.
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Kviljo! I always love your bows. Too bad this one didn't last. That design is almost like a less extreme design of adam karpowicz's low stack design. Anyways, great bow. What did you do for that handle? I like it a lot.
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Looks like my first r/d ::)
Work with a powerlam, 40cm long to get the handle area stiffer and don't ad to much deflex 2 -3 cm is normally enough.
The laminations should bend nicely round when you clam / press them into the form. If they not, taper a bit more so they do.
acker
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It broke about 2/3 in from the right limb. The glue line between the beech and the cherry did fail in the break, but I think the backing went first. I broke the other limb on purpose, and it snapped quite easily. On that limb, the glue line did not fail. The backing was quatersawn ash with no real flaws, and should be pretty safe so I'm a little puzzeled by it.
I think perhaps it was a combination of the low humidity and the choice of woods that led to the breakage. Ash is usually stiffer than beech, so the beech just under the ash backing might have put extra stress onto the ash. It should probably also have been bending more in the outer 1/3.
Perhaps? Any expert tips on the R/D-design is very much appreciated :)
My last bow is backed with ash. So far, a verious serious shooter.
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sorry to hear that kviljo - I'm sure your next will be a good one ;)
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I don't know, I would not use beech in a bow I guess; too short fibers I'd say...
Could that be the reason for the frailure??
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The beech might have put more stress onto the ash bacing, but beech alone works nicely as selfbows. I've made 20-30 board selfbows from it - both longbows and flatbows.