Author Topic: Potential flight bow  (Read 5981 times)

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Offline PatM

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Potential flight bow
« on: October 27, 2013, 11:25:39 pm »
Ipe/bamboo/sinew with spliced in Elm recurves. 50 inches t-t.
I just applied the sinew yesterday so it it will be a while before any bending takes place. You can faintly see the v splice under the fairly clear glue/sinew matrix. Other photos show handle area and mid-limb



« Last Edit: October 27, 2013, 11:40:11 pm by PatM »

Offline adb

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Re: Potential flight bow
« Reply #1 on: October 28, 2013, 12:30:58 am »
Will sinew do anything over bamboo?

Offline PatM

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Re: Potential flight bow
« Reply #2 on: October 28, 2013, 12:33:54 am »
What do you mean by "do"?

Offline adb

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Re: Potential flight bow
« Reply #3 on: October 28, 2013, 12:41:14 am »
I mean will it add performance and hold together?
« Last Edit: October 28, 2013, 11:20:36 am by adb »

Offline wood_bandit99

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Re: Potential flight bow
« Reply #4 on: October 28, 2013, 12:51:05 am »
It would pull it into reflex and if applied very thin like he did it would add very little weight to the limbs
Yew and osage, BEST. WOODS. EVER! Shoot straight my friends!!!

Offline PatM

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Re: Potential flight bow
« Reply #5 on: October 28, 2013, 01:07:49 am »
I want to maximize drawlength which is why I used bamboo plus sinew. The sinew is actually thicker than it appears although it will shrink down quite a bit.
 The bamboo already reflexes the bow and the sinew protects the bamboo and adds further reflex.  I'm trying to store energy through the whole thickness.
 Al of these materials are very heavy but the bow is very narrow so the strength of the materials should make them be efficient due to a thick cross section having greater potential energy storage IF the materials can take the strain.
 The sinew is very thick over the handle and then tapers out to the base of the recurves.
 Here's the handle/fade area.
« Last Edit: October 28, 2013, 01:15:16 am by PatM »

Offline Joec123able

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Re: Potential flight bow
« Reply #6 on: October 28, 2013, 02:05:04 am »
Ohh wow should have a gorgeous profile when complete
I like osage

Offline J05H

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Re: Potential flight bow
« Reply #7 on: October 28, 2013, 02:24:49 am »
I really like the look of this bow. Can't wait to see her finished. Gonna have a great full draw profile.
If you never have time to do it right, you'll always have time to do it over.

Offline Lukasz Nawalny

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Re: Potential flight bow
« Reply #8 on: October 28, 2013, 04:24:15 am »
Looks realy great. Ipe belly and sinew give great performance.Ipe is some horn substitute for me. Last time I make similar bow, but with bending recurve ipe/maple sinew.  Only 38 lb at 28" shoot 270 yards with flight arrow. You can expect great results with 50 lb + draw weight. In classic composite with horn core wood  is almost out of work. I experiment with ipe composite and I see that thickness of ipe should be not big , best results give 2-3 mm . It is strange but Ipe thickness have not big influence on draw weight, but give a lot of extra mass. I regulate draw weight in such coposite by middle layer wood thicknes and shape of bow
« Last Edit: October 28, 2013, 04:46:15 am by Lukasz Nawalny »

mikekeswick

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Re: Potential flight bow
« Reply #9 on: October 28, 2013, 04:57:27 am »
Looks realy great. Ipe belly and sinew give great performance.Ipe is some horn substitute for me. Last time I make similar bow, but with bending recurve ipe/maple sinew.  Only 38 lb at 28" shoot 270 yards with flight arrow. You can expect great results with 50 lb + draw weight. In classic composite with horn core wood  is almost out of work. I experiment with ipe composite and I see that thickness of ipe should be not big , best results give 2-3 mm . It is strange but Ipe thickness have not big influence on draw weight, but give a lot of extra mass. I regulate draw weight in such coposite by middle layer wood thicknes and shape of bow

You should use maple for the core of composites, certainly nothing much more dense. Ipe has horrendous gluing properties for natural glues.....The Turks had it all figured out  :)

PatM - yes the thicker the limb (all things being equal) the faster it will virbrate. Thick/narrow will outshoot wide/thin even if the cross sections are optimal for each wood. Frequency of vibration.

Offline Badger

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Re: Potential flight bow
« Reply #10 on: October 28, 2013, 08:25:15 am »
  I like the design very well, the only problem that might occur is adding sinew over bamboo, did you scuff up the bamboo? things don't like to stck to the surface. The fibers on bamboo are very sensitive to being violated by things like heavy sanding. Maybe th sinew will hold it all together. Looking forward to the results, should do well if it stays together.

Offline SLIMBOB

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Re: Potential flight bow
« Reply #11 on: October 28, 2013, 08:39:09 am »
Interested in the results.  Keep us posted.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.

Offline ssgtchad

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Re: Potential flight bow
« Reply #12 on: October 28, 2013, 10:27:01 am »
That's a really nice sinew job. I haven't any experience with sinew,  in the picture it looks like the sinew is  overlapping the joint between the ipe and bamboo, which I would protect the bamboo from splintering if it had been sanded.  How thick is the sinew, did you make your glue,  and what type did you use  sinew, hide, or fish bladder. Can't wait to see the results thanks for sharing.
Always learning something new.

Offline PatM

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Re: Potential flight bow
« Reply #13 on: October 28, 2013, 10:47:54 am »
The bamboo is sanded and scored longitudinally and acts as little more than a core that is holding some reflex. It should be well protected by the sinew. The sinew does just cover the edges but doesn't actually go around onto the Ipe.
 The bamboo is also in two pieces with an overlay at the handle to cover the joint and then feathered out.
 The Koreans use a bamboo core but they do flip it so the inside of the bamboo is on the back.
 The glue is just Knox and the sinew was all put on in one go. Can't tell for sure the thickness at this point but I would say about 3/16 at the handle tapering out to the tips.
 
« Last Edit: October 28, 2013, 10:52:52 am by PatM »

Offline PatM

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Re: Potential flight bow
« Reply #14 on: October 30, 2013, 12:05:03 am »
Slightly better view of the v splice through the drying sinew/glue. Bamboo underlay on belly of v splice.

« Last Edit: October 30, 2013, 12:12:34 am by PatM »