Primitive Archer

Main Discussion Area => Bows => Topic started by: david w. on May 11, 2008, 05:08:43 pm

Title: osage bow dimensions
Post by: david w. on May 11, 2008, 05:08:43 pm

i am going to start whittling down my osage pile now :)

How does this sound 64" ntn with a 8" riser pulling 55-60# @ 26" and hickory backed  with 3" of reflex glued in

Title: Re: osage bow dimensions
Post by: david w. on May 11, 2008, 05:10:21 pm

o and 1 1/2 at the fades

Title: Re: osage bow dimensions
Post by: shamus on May 11, 2008, 05:14:46 pm

sounds good.

I'd make the limbs with a gradual width taper. 1.5" at the widest point (where the width flares out at the handle) and from there it should taper gradually to just under .5" at the tips. I strongly advise a gradual width taper. Imagine a very gently pyramid shape. It makes for a snappy bow with osage.

details here: http://analogperiphery.blogspot.com/2007/03/selfbow-handle-dimensions.html

Title: Re: osage bow dimensions
Post by: Pat B on May 11, 2008, 06:47:18 pm

David, that sounds fine although you could go a bit shorter if you wanted to...60" to62" for 26" draw. Pre tiller the belly so you get a nice even bend on your form. This will give you a nice even bend after. If you just pull it into reflex without per tillering most of the bend will be at the handle.  Keep us posted.     Pat 

Title: Re: osage bow dimensions
Post by: david w. on May 11, 2008, 07:07:22 pm

ok but these are boards so how far would i need to pre tiller it?  I am starting on one of my lesser boards first because its dry, but this is still a very nice board

ok i may go a little shorter. i dint know i could make it that short with a stiff handle

Title: Re: osage bow dimensions
Post by: david w. on May 11, 2008, 11:46:48 pm

if the belly takes any set wouldnt it be hard to glue on the backing?

Title: Re: osage bow dimensions
Post by: Pat B on May 12, 2008, 12:35:22 am

David, Basically you will floor tiller it. Not enough to cause stress or set but enough to get a nice even bend when put on the form. Pat

Title: Re: osage bow dimensions
Post by: david w. on May 12, 2008, 12:38:37 am

thanks Pat that explains it now

Title: Re: osage bow dimensions
Post by: radius on May 12, 2008, 04:04:06 am

david, look at my bamboo backed osage:  non-bending handle only 4 inches, no problem

I was going to pretiller my boards, too, but Gordon asked me "why tiller it twice?" so i just glued on the backing and then tillered it.  On the other hand, i didn't put any reflex in it...

I am working on a reflexed osage/hickory right now with a built up riser, and what i;ve found is that the limbs bend in sort of a gullwing shape as they come off the handle.  I didn't pre-tiller.  Just glued a 9/16 piece of osage to a 3/16 piece of hickory in deep reflex.  I am finding that the thicker the backing strip, the more reflex a bow will hold after tillering.

radius

Title: Re: osage bow dimensions
Post by: david w. on May 24, 2008, 08:27:41 pm

thanks radius that helps.

pat since my other bolong board had a crack i am going to try my 61" board.  IF there is a 5-6" stiff handle can i still get 26" draw?

thanks
david

Title: Re: osage bow dimensions
Post by: david w. on May 24, 2008, 08:33:37 pm

I remeasured it i can maybe make a 62" ntn or 63" ntn bow

i think i will get a bow :)

Title: Re: osage bow dimensions
Post by: radius on May 24, 2008, 09:24:19 pm

i see you're offline right now:  i presume that means you're off scratching wood?

Title: Re: osage bow dimensions
Post by: FlintWalker on May 25, 2008, 02:38:24 am

David, if tillered carefully, you can easily get 26"-28" of draw from a 60" piece of osage. ;)  Saw Filer

Title: Re: osage bow dimensions
Post by: wytetale on May 25, 2008, 04:45:39 pm

Dave, put a power strip in. make it 4" longoer than your riser. 1/4- 3/8 thick in the center and taper it to a knife edge on each side. center it so it extends 2" on each side of your riser. I have made alot of 58" bbo bows like this that draw 28" and 50- 60lbs.

Title: Re: osage bow dimensions
Post by: david w. on May 25, 2008, 06:26:46 pm

thank you very much.  I amnot sure what a knife edge is.

Title: Re: osage bow dimensions
Post by: david w. on May 25, 2008, 06:36:02 pm

my board is 1 1/8" thick i was just going to leave it the full thickness there and bring it 1/2 past the fade out.  then i was going to glue on a 1/2 piece of cherry on top of that to make it 1 5/8.

this handle is 1" wide so it pretty narrow but since it thick i think it will hold up

Title: Re: osage bow dimensions
Post by: CutNShoot on May 26, 2008, 11:32:47 am

knife edge is Very Very thin on the end edges of the piece after sanding where it fades out. You can see light through them.