Author Topic: Best design for 38-40" draw length?  (Read 10630 times)

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Offline EdwardS

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Best design for 38-40" draw length?
« on: November 15, 2016, 08:03:03 pm »
Yeah, that's DL, not OL.  I was born with Marfan syndrome, a genetic disorder that makes you excessively tall and skinny normally, as well as making your arms and legs oversized for even your height (I stand 6' 7" in my leg braces, but have an armspan of 7' 4".)  It causes a lot of other serious problems as well, like multiple organ failure in my case (under control at the moment, though) but I've been an ardent archer and bowhunter since about four or five.  I've made my own bows before, and I've even been able to make one cable-backed red oak that would draw to 36" but I took too much wood off as it was my first bow and it got overstressed.  Still draws, still shoots but has no cast.

I own a horn bow that handles my 36" arrows just fine, I have an osage longbow that draws 34" and a bow of materials that shall not be named that can do 36".  But even that feels short and unnatural.  I use thumb draw, as my fingers were mangled in a wreck and while I can shoot three under, I have some trouble with a clean release.  I can honestly draw to 42" but every inch makes getting shafts harder and harder to do.  I studied kyudo and Manchu archery, so long draws are something I'm very accustomed to.

At this point, I have roughly one limitation on what I will do-I am allergic to osage, to a point that requires hospital intervention.  So I can't use it.  Other than that, I will take advice, listen, accept that people here have forgotten more about bowbuilding than I ever knew, and generally just be thankful for the help.

I have here privet (ligustrum sinense,) crepe myrtle, possibly some straight maples, silver birch, a 100 year old chunk of red oak, and I can buy 8 foot boards of ERC.  I have enough sinew to make a few bows, plenty of hide glue, and enough rawhide for at least one backing.  Toolwise I have various files, a farrier's rasp, a 9" bandsaw, and lots of knives.  Most wood would have to be felled and worked green to be put up to dry (though I have plenty of dry space to do so) but it's cooler weather, so that's OK.

Anything else I would have to hunt pretty hard for, but I should have tree of heaven (ailanthus) and hackberry that I can cut, and there used to be a few hop-hornbeam and hickory saplings.  All depends on how well I get around on my new hip.

Thanks in advance, even if all you got is "I got no idea."

Oh, and if you're interested in learning more, you can visit www marfan.org to learn more about my condition.   

Offline willie

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Re: Best design for 38-40" draw length?
« Reply #1 on: November 15, 2016, 09:01:58 pm »


With a new hip, maybe a board bow? just curious what poundage you prefer, and do you take a liking to bows made from lighter wood or simple designs?

and welcome

Offline EdwardS

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Re: Best design for 38-40" draw length?
« Reply #2 on: November 15, 2016, 09:12:00 pm »
I'm shooting for around 45 pounds, and I like Native American styles, but I own an Assyrian hornbow, a modern materials hockey stick style static, the osage longbow, and I made a hickory spliced static as my most recent.  That's been a while, as I spent most of this year laid up.  I'm enjoying being up on my feet again, but I'm unable to get any boards but red oak and ERC, so I'm not sure exactly how useful that will be.

Offline willie

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Re: Best design for 38-40" draw length?
« Reply #3 on: November 15, 2016, 09:55:17 pm »
I was asking about preferred styles to see what kind of materials seem to shoots well for you so far.  If you have to scale up a design to accommodate longer draws, 45# could be considered light for what longer limbs are capable of.

Offline George Tsoukalas

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Re: Best design for 38-40" draw length?
« Reply #4 on: November 15, 2016, 10:12:33 pm »
Edward,

Red oak is a fine bow wood in board or stave form. I think you said you had access to it.

For a length for a selfbow double your draw and add at least 20%. If backed you can go shorter

Choose  straight grained boards.

There's a buildalong on my site and you can use 1 3/8" for 45#.

You have a 100 year old piece of red oak? Interesting. Not sure if that would work though I've used 30 year old red oak boards.

Maple is a fine bow wood also. I have no experience with the others you mentioned.

http://traditionalarchery101.com/boardbowbuildalong.html

Jawge
Set Happens!
If you ain't breakin' you ain't makin!

Offline bubby

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Re: Best design for 38-40" draw length?
« Reply #5 on: November 15, 2016, 10:15:01 pm »
I have built bows from tree o heaven and privet and while they will make a decent bow i don't feel that they will work for that draw length. Now i am thinking a maple or a hickory core with bamboo back and belly with a bendy d bow design and static recurves. Make it at least 72" long and maybe a little more like 76" ttt. Come to think of it you probably don't need the boo belly
and maybe yellow heart would make a good belly wood in that case
failure is an option, everyone fails, it's how you handle it that matters.
The few the proud the 27🏹

Offline loon

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Re: Best design for 38-40" draw length?
« Reply #6 on: November 16, 2016, 12:13:40 am »
Would asymmetry help? Maybe deflex recurve?
I want to make a 50" bamboo nylon cable backed bow with a 33" draw length... and static recurves, and setback handle
Dowels from the hardware store get pretty long sometimes
Ali bow sells arrows up to a meter long I think (39"). There's also the bamboo shafts on ebay. I have some 4' bamboo sticks that are all crooked ... ...
Good luck
« Last Edit: November 16, 2016, 12:18:39 am by loon »

mikekeswick

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Re: Best design for 38-40" draw length?
« Reply #7 on: November 16, 2016, 03:41:22 am »
Bamboo arrows are available - look for a fella named sventiger on atarn.net - that is where everybody else who is selling long boo shafts gets them from.
At the end of the day any bow wood will work. It is simply a case of scaling everything up to your drawlength.
40 inch draw compared to a 28 inch draw - 40/28 = 1.4286      so take the figures that work for a 28 inch draw bow and multiply width and length by 1.4268.
The key is going to be getting your tiller correct. Too much bend inner limb and you will get handshock. Make a parallel width bow that tapers to the tips about 10 inch from the nocks. Elliptical tiller. There shouldn't be any problems.
You can get boards through the mail. Maybe try trading with somebody on here?

Offline Selfbowman

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Re: Best design for 38-40" draw length?
« Reply #8 on: November 17, 2016, 11:22:06 am »
I don't know. I will guess. 84" 1 3/4 at fades. Using Osage . Ten inch handle.  Get the ends narrow. Arvin
Well I'll say!!  Osage is king!!

Offline Parnell

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Re: Best design for 38-40" draw length?
« Reply #9 on: November 17, 2016, 12:03:11 pm »
Hello Edward, very interesting about your condition.  I've learned some about that over the years.  I hope things continue to go well for you.
I'm sure its all very doable but the trick will just be to find staves cut to what you'll need...
Years ago I tought a young fella and he made a hickory stave flatbow that we took out to about 33".  He is 6'11". 

Wish you the best in your pursuit.

Steve Parnell
1’—>1’

Offline Marc St Louis

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Re: Best design for 38-40" draw length?
« Reply #10 on: November 17, 2016, 12:48:40 pm »
It's a bit of a challenge but I see no reason why it can't be done.  Could possibly get the bow length down into the low 70" with the right materials and the right design.
Home of heat-treating, Corbeil, On.  Canada

Marc@Ironwoodbowyer.com

Offline Urufu_Shinjiro

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Re: Best design for 38-40" draw length?
« Reply #11 on: November 17, 2016, 01:34:55 pm »
I don't know if it's something you want to try yourself but I would honestly look at the Japanese Yumi, a tried and true design for a long long draw, and Ya, or yumi arrows are up to 43" or so. Just thinking out loud.

Offline make-n-break

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Re: Best design for 38-40" draw length?
« Reply #12 on: November 17, 2016, 02:13:15 pm »
I can make quality split lumber, machine-spun, non-tapered shafts of any length. Im currently set up for 21/64, 11/32 and 23/64. I'm very picky about grain orientation and use only the most carefully selected dimensional lumber. If you'd like, I would be happy to send you a dozen as a Christmas gift, if you're inside CONUS. Douglas Fir maybe?
"When making a bow from board staves you are freeing a thing of dignity from the humiliation of static servitude." -TBB1

Offline EdwardS

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Re: Best design for 38-40" draw length?
« Reply #13 on: November 17, 2016, 08:49:56 pm »
I would absolutely love that!

I'm leaning toward a Manchu style bow right now.  I can hit at roughly 72" what would take 76-80" to hit otherwise.  Plus, it would be easier for me to find the wood or bamboo necessary since longer staves are harder to find.

At 45 pounds, do I absolutely need horn or will a heavy backing of sinew work?  Any resources you guys can point me at will help.  I have Karpowicz's book, and follow Peter Dekker's Manchu Archery FB page, and I may still have an ATARN account lying around.  Even so, studying is not doing, and I would be very appreciative of any experiences you guys want to share.

Offline Badger

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Re: Best design for 38-40" draw length?
« Reply #14 on: November 17, 2016, 09:24:05 pm »
     This is a challenging project to come up with a good shooter. Simply scaling up would suggest a bow of heavier draw weight. I would try a light wood like poplar or soft maple. I built a 40" draw poplar bow once but it was too short and took excessive set. At 80" I think you would be fine. As you already know arrows will be a challenge, you will need well over 100# spine measured at 26" centers. Most likely this will require at least a 13/32 shaft. You will have a lot of stored energy so you should be able to tolerate heavier arrows like maybe 650 grains and not sacrifice too much speed, lighter would be better of course but I would look for lighter arrow woods. Some of your straight grained pines might work well here.