How thick is your taper on your middle lamination for a R/D bow

[ccase39]

Just finished my first R/D bow. It came out ok other than the fact is was a little lighter than I wanted but I kind if expected that would happen as I learned to tiller it. Its straight Osage board with a bamboo back. The next one I try I want to do a tri lam with Osage or Golden Heart belly backed with bamboo and a thin lamination between the boo and belly. What thickness do you recommend starting at the handle and tapering out to the tips? Do you know anyone who sells these lams in solid wood that will run the legnth of the bow? I have found some at 36" each but want to avoid having to but them together at the handle because I know I will have a gap.

[Hrothgar]

If you're making a wide flat-limbed composite bow the limbs will be very thin. Youwill probably need to work out taper on the middle lam. Are you adding the middle lam for accent purposes only? That's more work than I normally put into a bow .

[ccase39]

Accent but I imagine it will add a bit of strength. I have been making them for Christmas presents but the problem is they keep getting better and better and prettier and prettier so all of a sudden I dont want to give away the first few because they dont look as good lol. And then of course I need to make a couple for my own use. I really like my R/D but the tillering is a challenge. I dont know if I am lucky or just have a decent eye but with the flatbows I seem to rough it out, floor tiller it and then sand it until it feels right and by the time I put it on the tiller board its pretty much there. The R/D bow was a whoooole different story.

[Del the cat]

For an ELB I work on a thickness taper of at least 1.5mm every 6", that's about 0.06 in 6 so that's 1:100.
But there's not much width taper on an ELB.
That's just a roughing out figure, in a finished bow it's prob' a tad more.
Del

[ccase39]

Do yall find that R/D bows work better longer like at 72 inches or shorter like 66? I built mine 72 this time because I find longer bows are a little more forgiving to tiller.

[Hrothgar]

I've flipped the tips on before, but never really made a R/D bow.What's the purpose, hunting or target bow?

[GB]

I've made mine 66" for my 27" draw.  I adjust the thickness of the core lam depending on how thick the backer and belly lam are.  The Osage belly wood I buy is 5/8" thick.  I rip them in half and wind up with two lams around 1/4" after losing the width of my table saw's blade.  I want about 5/8" or 9/16" total thickness at the center of the bow to start with for the 45# bows I make.  If I use a 1/8" hickory backer, then I'll make my core lam 1/4" to 3/16" thick.  With my 1/4" belly lam, I'm in the ballpark.  I want the tips to be a little over 3/8" thickness, so that means I need to taper the core lam or both the core and backer so I don't end up rasping most of my Osage belly wood away at the tips.  It's not an exact science, but if you have a good idea of the thickness you need at the handle fades and tips for the weight of the bow, you can adjust the thickness of the lams to put you in the ballpark.  I like a mid density wood for the core; red elm, maple, cherry, walnut, etc.
You can just make a skive joint and super glue your half length lams together.  I like Unibond or Smooth On for the glue up.
A guy who has made a lot of this style of bow is doing a build along on TradGang right now:

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=013158