Belly "lam"

[DC]

I'm running out of Yew. In order to make the most of what I've got I want to make a riser insert out of knotty, sappy junk Yew and then glue a steamed to shape belly piece on following the curves. I'm sure this has been done before. Once they are glued together I'll just treat it like any billet. This allows me to cut my remaining yew into about 3/8" or even less thick strips. It also eliminates any danger of riser pop off. My question is does the strip have to go right under the riser like "A" or can I shorten it and end it on the fades like "B". This also allows me to use about 2" shorter wood.

[simk]

i'm gettin away with b. not tested over 45# though. make the fades a little longer maybe.

[DC]

Good! The curves will be flatter. That was the biggest paint can I had to trace around

[mmattockx]

My question is does the strip have to go right under the riser like "A" or can I shorten it and end it on the fades like "B". This also allows me to use about 2" shorter wood.

Since fibreglass lams stay attached to a riser when glued like B with the strain levels they see, you should have no issues doing that with a wood lam. By the time the stack height going up the fades is twice the limb thickness stresses have dropped to 25% of what they are right at the end of the fades and you really don't need the belly lam any longer to carry the loads.

If you use a maple core to bulk up the stack you could use much thinner yew lams without compromising the performance much, if any, and make your stash of yew last even longer.


Mark

[DC]

If I use a core then I'm into the laminated bow world. If I do it this way I can still pretend that it's a backed selfbow

[bownarra]

B - no problems.
The issue with doing it this way is preparing the end of the riser to a true feather edge for an inch.

[Tommy D]

If I use a core then I'm into the laminated bow world. If I do it this way I can still pretend that it's a backed selfbow

Is this why you don’t put a “power lam” between the bamboo and belly? Surely it would serve the same function to stop the handle popping off!

[DC]

B - no problems.
The issue with doing it this way is preparing the end of the riser to a true feather edge for an inch.

I'll roughly shape the pieces, glue them together, sand the back flat and then glue on the backing

Is this why you don’t put a “power lam” between the bamboo and belly? Surely it would serve the same function to stop the handle popping off!

With the Yew strip only being 3/8 or so thick I just wasn't sure that a power lam would accomplish much. In this case the riser is sort of a really thick power lam.

[mmattockx]

Is this why you don’t put a “power lam” between the bamboo and belly? Surely it would serve the same function to stop the handle popping off!

Lots of guys use a power lam in the stack to help prevent the handle popping off. What DC is proposing would have no issues with the handle popping off because the compression forces ride the surface of the belly up onto the handle riser, instead of underneath it.

I'll roughly shape the pieces, glue them together, sand the back flat and then glue on the backing

That's an interesting approach. As long as you are careful with your belt sander you would get a really nice, smooth transition off the riser into the limb.


Mark

[DC]

I'm trying this out with scrap wood. I've steamed and clamped the belly and cut out a pattern tor the riser. I used an old 2x4 scrap for the riser pattern and as I was making it the thought crossed my mind that I could almost use this as a riser. It's only going to go to the end of the raiser at the most. The limb will probably thin out more as I tiller. So how good does the wood have to be? Does it have to be bow wood?