lamination specs for a longbow

[rkmnt2]

I want to build my daughter a longbow. I have a model that I want to copy but it's much heavier than the one I want to make for her. So how do I come up with the lam thickness's and taper rates other than just trial and error? Could get a little costly. If there isn't a formula or chart that I could get my hands on....how bout your best guess?
   60" with a slight R/D. About 35-40# @ 27".

[kennym]

60" with a slight R/D off my form-

15" riser,1.5" wide at fades to 9/16" wide at nock ,.002"taper is   52# @ 28" at 340".  60# is .350"

My guess without seein your form is .315"!! LOL

[sulphur]

binghams catalog has a pretty decent chart in the back of it.  You'll have to pay a few bucks to get it but its been a decent reference.  Also kenny has been just as good for lam specs.  two sources couldn't hurt.   kennys spec seem to my limited experience to be pretty close.

[kennym]

Here is their chart,its hidden in the FAQ section!! LOL

Don't think they have a one-pc r/d tho......

 http://www.binghamprojects.com/drawweight.htm

[rkmnt2]

I think I've got a pretty good idea of where I'm going with this. The first one is going to need a little fine tuning to get it close but eventually it'll be a piece o cake....right? lol

[onemississipp]

I would try something around .334”  
That is 2 pcs. .040” glass
3 parallels @ .050”
and 1 taper @ .104” (.002)


I came up with those numbers after a lot of thought and research...

62" Delfex/Reflex one piece longbow
18" riser

shooting for 45# @ 28"

Good luck, I plan to build this bow when other things slow down...

[onemississipp]

As you can see my numbers and Kenny's are pretty close even with his bow being 2" shorter and the riser being 3" shorter.

[rkmnt2]

Nice! Now that brings me to another question. You both spec out .002 taper. Why....or why not?
  Dustin. Is the width of yours similar to Kenny's too?

[onemississipp]

Width would be the same...I think a .002 taper will make for a smoother arc in the limbs. Smooth arc = less stress.

On the width you can start wide and then decrease if poundage needs to be dropped.

Remember these glass bows are tillered from the sides..

[onemississipp]

I have a chart I was building, I'll have to find it. But it had pics of bows with the specs and the final poundage of said bows.

If I come across it I'll send you a copy.

[rkmnt2]

That would be cool. Thanks.
   And congratulations on winning Kenny's lams. That makes another project a little easier to start!
   Don

[onemississipp]

Thanks, it sure does..I have a Possibles bag build along I need to post..will be starting a plains style quiver on Monday...Have to build another bow can't let Kenny's lams sit around..and a million other things.

[Asafan]

It is possible to make bow more longly on 4-6 " and trimming to receive the necessary force for lady. For 27 " she should be... big length.