Primitive Archer

Main Discussion Area => Bows => Topic started by: CTBowyer on June 11, 2007, 12:24:10 pm

Title: need help with composite dimensions...
Post by: CTBowyer on June 11, 2007, 12:24:10 pm
Hi all,

I've been making bows for a couple years now.  I've made selfbows and backed ones a plenty but now I want to try a sinew/horn Turkish style composite.  Anyone know roughly what the dimensions should be? (thickness of core, thickness of horn, #layers of sinew, angle of siyahs, etc...)  I'm aiming at making a 50-55" bow that pulls about 50# @ 28".  Any help in figuring this out would be great.
Title: Re: need help with composite dimensions...
Post by: a finnish native on June 11, 2007, 12:31:49 pm
this might help.  http://198.170.108.27/phpBB2/index.php
Title: Re: need help with composite dimensions...
Post by: tom sawyer on June 11, 2007, 04:15:19 pm
Here's a bow I made not too long ago.  I think there's enough info with the pics to give you some idea of the dimensions.  It has settled in at closer to 62lb@28" now.

http://s96.photobucket.com/albums/l200/62tomsawyer/Asiatic%20Composite%20Bow/

http://groups.msn.com/LenniesBowPage/abcwannabes.msnw?Page=1

I can tell you that its kind of tough to predict exactly what weight you are going to have as far as poundage.  There are a lot of variables.  Limb length, limb width, amount of reflex, angle of siyahs, thickness of core, thickness of sinew, thickness of horn.  Leave the horn belly over 1/8" thick if you can, because you can tiller with the thickness that way.  It works very nicely with a scraper.

I was surprised I didn't get more reflex when I sinewed the bow, but I'm kind of glad it came out this way.  It was stout enough as it was.  If I do another, I'll probably use a slightly thinner core and slightly more sinew and horn.

One other tip, one of my siyahs is slightly crooked.  Pay special attention to lining things up when you do your v-splices, it doesn't take much to get it crooked.  The splice cuts weren't crooked, there's just a little play in them so you can get a "leaner" if you aren't careful.

The whole time I was making this bow, I really figured it was jut going to blow up.  Amazingly, it has survived and even shoots pretty darn good.   
Title: Re: need help with composite dimensions...
Post by: waterlogged on June 11, 2007, 04:34:35 pm
http://198.170.108.27/phpBB2/viewtopic.php?t=716&start=15

(sorry about that... took the url from the wrong window, lol)

Someone posted some good dementions for a beginners hornbow, it's the first download (needs acrobat reader, which is free). Those dementions should at least give you a starting point.  should at least give you a starting point.

Good luck.
Title: Re: need help with composite dimensions...
Post by: CTBowyer on June 17, 2007, 01:45:02 am
Thanks guys, really big help.  (Now I just need to wait for the horn to get here so I can begin!)
Title: Re: need help with composite dimensions...
Post by: tom sawyer on June 18, 2007, 01:01:14 pm
Lots to be done while you wait.  Core prep, sinew prep, siyah prep, handle piece prep.

If you haven't seen it, Thomas Duvernay's DVD on making Korean bows is a good instructional video.  You don't have to make a Korean bow to get something out of it.