Core wood for bamboo back and belly ?

[Manolovis]

Hi everyone
What sort of characteristic a core wood  needs to have on a trilam boo back and belly ? Density ? Mor Mor ?
Thanks
Manu

[bownarra]

Hard maple, black walnut or bamboo (natural or lamianted flooring).
If you can get hold of b.walnut I wouldn't use anything else.

[Hamish]

Medium weight, and strength, stable, resistance to shear. Maple, ash, walnut, elm, oak.
Light woods like fir and spruce, pine, are said to make a fast bow, but are the weak link in the chain, because they fail first.

Clear yew would also be a good option, as would flattened bamboo(or bamboo ply commonly used as lam's  in fg bows).

You could also use a heavy tropical wood like purpleheart, for the contrast, looks good.

Lol Bownarra just beat me to the post, very similar

[Manolovis]

Thanks ! I have a board of black walnut, ash and Tasmanian Blackwood...all of them seems to be good candidate then? I wanted oomph the bow performance and get the match boo/wood that will give the most speed  ( providing I nail the tiller damn right😁) . I was thinking of a flatbow design recurve/reflex with the last 6 inches quite stiff. The bow would be 62” 45-50# @ 28”. Thinking of 36 mm max width.
Any insight with wood options and specs for what I want to achieve with minimal set  ?

[Hamish]

 Bamboo laminates are preferred with fg designs for performance.  I've never heard of anyone using really hard dense tropical timber for
core laminations, like is commonly done with elb tri lams. It doesn't need to be incredibly strong in tension, or compression, as the core is under neutral strain, except for shear.

I honestly don't see much if any difference in how well a bow shoots(as long as its tillered properly) depending upon what the core lam is in my tri lams. You would need to do a test with a chrony, and see if any consistent results showed up with a certain combination.

[Manolovis]

So hamish do mean then if i want to take advantage of the wood property of the core the design needs to quite narrow and tend towards elb style?

[Hamish]

Not necessarily with Elb design. That is just the design that I have made the most tri lams from, also made plenty of tri lam flatbows too. Hickory or boo backed, tropical hardwood core(or walnut), lemonwood, or bulletwood belly.

I have never made boo back and natural boo on the belly. I have made some with boo floorboard for the belly. They were really pleasant to shoot, but don't contain maximum power fibers like you get  with natural boo, with the rind and nodes intact, on the belly. Therefore the limb width was wider, to counter set. You can make a narrower bow with natural boo on the belly, because the material is denser, and you can heat temper it to increase the resistance to compression.

The core for the type of bow you want, I suspect the pre tiller taper is more important than the type of wood you chose.

[Manolovis]

Gotcha! I m following closely the tread on tiller vs performance to see what type should I aim for. I don’t know if that the way to do but with the one that I just completed, I roughly taper the core, glued the back with reflex, and tillered to full draw at about 25 lbs. then I added the boo belly and fine tuned the tiller.