Tri Lam Bow ....HELP

[Stoner]

First off I want to thank everyone who supports this forum and resurrected it. It has been a long minute since I have posted anything and I need all your knowledge to help me with an all wood laminated bow. I have tried 3 1/2 to 4 times now and failed. With 2 of them shooting then for no reason they said nope not today.

Need help with the following:

1) Layout - handle to fades, limb width & length
2) Wood -grain orientation & species
3} Asymmetric or symmetric

Here is the wood and layout that I am trying this time. Layout as follows 4" handle, 2" fades, 29" working limbs. In the past I have divided the limbs into thirds. One third straight & two thirds tapper. Starting with quarter saw osage 0.495 appox. 1/2"thick. I have the grain drawn with a red pencil so you can hopefully see it runs relatively straight. black pencil shows the centerline and 1-3/4" wide straight taper to the nock at 3/4" wide.

Please be blunt and let me know if I'm drinking my bath water again. Thanks John 3:16

[Stoner]

Here is the Hickory backing. Quarter sawn at 0.175 aprox. 3/16 thick. I know hickory performs better under tension than compression. Also wanted another wood for the final backing.

[Stoner]

And finally the finished backing curly maple 0.110 aprox 1/8" thick flat sawn. You will also see the hickory laying naext to it both have no grain run out.

Once again thanks in advance. John3:16

[Hamish]

Not sure that I understand correctly, do you want the curly maple as the backing instead of the hickory? Curly maple is not a good choice for the backing, as the "curly" grain is inherently weaker. Hickory is the absolute best wood for backing. Curly maple is used on fiberglass laminated bows, but it's the glass doing all the tension work.

Grain orientation on the end grain, doesn't tell you much about how the grain is on the sides, and if there is significant run off or not. That information is crucial to the success or failure of the bow. Most important is the straightness of the grain on the sides of the backing

[bjrogg]

Stoner I’m really sorry I don’t have any useful advice but man I’m glad to see you here.

Curious though. What shape of riser? Deflex? Straight?i
Any pictures. You know we love pictures.


Bjrogg

PS I see you got a reply from Hamish and I would tend to agree with him.

I wonder if you could tiller it out a few lbs light hickory backed and then glue the curly maple on the belly. Then re tiller it. I bet that would look really cool.

[Stoner]

Hamish thanks for the reply the curly maple may get thinned down to 1/16 and is strictly for aesthetics. The working bow is osage and hickory. As for run out there is none on the hickory sides or face. The osage has grain running end to end but has some run in & out as it tappers(typical osage) but for the most part its stays true. This is why I tried to show the grain in red in the photo, hope you can see it.

[Hamish]

I'm not saying there is no way the curly maple won't work, but even if thin, it will still be taking all the tension, on the back, and is a weak link. It has the potential for the maple to "pop" like a on a really thin ringed tree stave. The hickory underneath might save it from a break, but it also might continue the break into the hickory. If you want a durable bow, I would leave it out.

3/16" hickory is also a little thick, for a backing if you are making a wide limbed flatbow, in a 40-70lbs bow. I'd go 1/8".

I'd swap out the curly maple, use a strip 1/16"-1/8" of a core wood to sandwich between the back and belly. Walnut or some other contrasting wood looks good.