Author Topic: bamboo backed hickory  (Read 713 times)

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Offline Bayou Ben

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Re: bamboo backed hickory
« Reply #15 on: July 11, 2018, 02:27:25 pm »
There's a lot of things that can affect dimensional requirements on laminated bows, but I usually require a little more thickness than what Ed has seen with his bows.  I've made a couple 60#'ers and they need to have a total thickness of about .6".  So .125" bamboo and .475" core.  And this doesn't leave you much room to play around with the tiller.  But those bows were a couple inches longer.
I agree with Pat.  That's about the only way to do it unless you are duplicating a design. 
   

Offline Mafort

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Re: bamboo backed hickory
« Reply #16 on: July 11, 2018, 04:14:00 pm »
 
When I did BBO's and BBH's I start out with a 3/8" thick core with 1/8" thick bamboo on a 64" long bow.At that time it's easily 65 pounds right off the form.Those were D/R bows 1 and 3/8" wide @ fades.Straight Line taper to 1/2" wide tips with a moderate reflex of a couple of inches induced past the back of the handle into the outer half of the limbs.

so i should clarify a few things so i can possibly narrow down the information needed. this is what this bow is but its a flat bow. its not a D/R.

Offline BowEd

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Re: bamboo backed hickory
« Reply #17 on: July 11, 2018, 05:00:54 pm »
That'll still be close to the same D/R or not when it comes to estimating thickness's for poundage.It's not hard to nail down close within 5 to 10 pounds the poundage during glue up you want without much tillering afterwards after you make enough of them.Perry reflexed bows are not deflexed any either.I just gave you parameters of what is gotten from a certain length/thickness/and width.I would'nt tiller it down to 40#'s though prior to glueing on bamboo to get 70 #'s.You did'nt state the width you've got now.
If I remember right I think my bamboo was tappered in thickness from 3/16" at fades to 1/8" thick or less at the tips.Thus making the initial fade thickness at 9/16" thick with a 3/8" thick core at fades and 1 and 3/8" wide @ fades.From that a 55# bow can easily be gotten.
To get 70 pounds I would start out a 1.5" wide with those thicknesses' stated on a 64" long bow.
« Last Edit: July 12, 2018, 01:11:57 am by BowEd »
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline Pat B

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Re: bamboo backed hickory
« Reply #18 on: July 11, 2018, 05:56:59 pm »
For the boo to be thin enough your bow will probably be no more than 1 1/2" wide to 1 3/8" wide. I think I'd take that width at least half way out the limbs before tapering to the tips at that weight.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Stick Bender

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Re: bamboo backed hickory
« Reply #19 on: July 12, 2018, 12:05:49 am »
When I made my BBH I pretty much followed BowEds recipe but my bow is 68'' parallel 1 3/8 wide ,I pre tapered the core lam and I would bet I only spent 20 minutes tillering the bow every body does it different but my belief is 90% of the tiller is done in the detail work before glue up !
« Last Edit: July 12, 2018, 02:23:01 am by Stick Bender »
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Offline Ryan Jacob

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Re: bamboo backed hickory
« Reply #20 on: July 12, 2018, 01:30:56 am »
Then again, thereís always a chance to screw up while tillering and end up losing more poundage (well, atleast for me). Iíd just save the strip for another bow and keep the finshed bow finished.
You donít know desperation till youíve split a stave with screw drivers.

Offline Stick Bender

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Re: bamboo backed hickory
« Reply #21 on: July 12, 2018, 02:37:23 am »
Here is another thought that we over looked he basicly is converting a already floor tillered self bow so Im assuming a handle/fade area of 8-10'', shorter riser then most BB backed bow so he needs to add thickness ?
« Last Edit: July 12, 2018, 02:44:51 am by Stick Bender »
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Offline Ryan Jacob

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Re: bamboo backed hickory
« Reply #22 on: July 12, 2018, 05:28:33 am »
Oh shoot I read floor as fully tillered. Well if weight gains the question, maybe 10 to 15 pounds, though Iím assuming that after flattening, tempering, and retillering, itís gonna be around the same weight, maybe a bit higher.
You donít know desperation till youíve split a stave with screw drivers.

Offline Bayou Ben

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Re: bamboo backed hickory
« Reply #23 on: July 12, 2018, 05:54:32 am »
Yeah Ritchie, a shorter handle means more working limb, essentially a longer bow as far as the limb thickness is concerned.

I'm a little confused as to what stage the hickory bow is in right now.  So it's floor tillered and you are assuming the finished weight is around 55 #'s? 
If so flatten the back and glue the bamboo on (add reflex if you want).  I don't think it will end up at 75 lbs after you flatten the back and tiller it out, but you have what you have. 

Offline Stick Bender

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Re: bamboo backed hickory
« Reply #24 on: July 12, 2018, 10:43:11 pm »
 There is a excellent DVD out on this topic by Dean Torges Hunting the bamboo backed bow it covers these type bows A to Z , I found it real helpful , some times with these laminate bows you just have to take your ideas and build them using the Wasg (Wild ass scientific guess) system and see where your at  unless your replicating a exsiting bow like was said ,if you come in heavy you have a lot more options , I enjoy trying to get as close as possible off the form as I can , but others enjoy scraping the bow to get there ! These guys around here have saved me a lot of time with there advice its good to pay attention to the details they offer it will save you a lot of time to ! Good luck with your bow look forward to seeing your post !
If you fear failure you will never Try !

Offline Mafort

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Re: bamboo backed hickory
« Reply #25 on: July 18, 2018, 04:45:36 pm »
so i am looking to out some recurve into this bow. how would i do so? do i recurve it and then back it? or do i back it and recurve it then? also would i use steam? or should i use heat? heat and oil? sorry for the questions i just want to make sure its done right. its for my friend and i dont want him to get hurt should it blow up. the back is flattened and ready for glue up as is the bamboo backing.

As for the stage the bow is in, its floor tillered right now. tiller is looking good and im assuming its around 55-60 lbs as of now.

Offline Stick Bender

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Re: bamboo backed hickory
« Reply #26 on: July 19, 2018, 12:02:20 am »
If your bow is floor tillered as a self bow its more then likely to thick to recurve or even reflex that much , you will need to get closer to Boweds & Bens recipe typically the recurves are done at glue up using reverse wedges, I have used and curently using reverse wedges on a bow same concept , the tip limb lams need to be thin enough to bend well, especially if your going for steep curves , typically there done in more of a slower reflexed fashion on this type bow , steep curves on laminate bows are hard to do unless using multiple thin lams in the tip areas , but you can get some fair reflex if the single core is thinned down ! With the more reflex or recurve form alignment becomes more critical at least for me ! If you have room to leave your front profile wide it helps with string alignment later ! You could also curf cut the tips to create thinner lams and insert wedges I have never did it that way but guys here have !
« Last Edit: July 19, 2018, 01:24:32 am by Stick Bender »
If you fear failure you will never Try !

Offline Stick Bender

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Re: bamboo backed hickory
« Reply #27 on: July 20, 2018, 04:19:39 am »
I had to cut some lams today so based on your recurve question I did some hill billy exsperments in the first pic the osage lam is at 0.110 a little under 1/8 '' and with heavy thumb pressure trying to get a tight bend thats the radius I got, the other pic is at 0.055 a little under 1/16 '' and getting tighter but to get any tighter I think you would need to go 0.040 for glue up curfed recurves  , Bubby just posted a bow with glue on recurves that might work for you !
« Last Edit: July 20, 2018, 04:52:35 am by Stick Bender »
If you fear failure you will never Try !