“Proper” Reflex/Deflex form - best shape

[Tommy D]

I have decided to make a proper form for making reflex/ deflex bamboo backed bows. Mainly ipe. Happy to do trilams. I also have some ash.

I have done a bit of internet research and it seems 1” deflex and 2” of reflex at about 66 inches for a 28 inch draw is a good starting point? And also to concentrate the deflex on the inner third of the limb?

I am open to suggestions before I shape it .... not looking for anything radical just something that will produce a good performer repeatably.

Thanks

[Badger]

     That is real similar to the one I have been using for years. My form has about 1" deflex in the inner third and the tips are glued up at 3 1/2 inches behind the back of the bow. Some of that is lost when I take the bands off and it usually ends up around 2" reflex.

[RyanY]

I would say aesthetically the ones that I think are the most attractive have almost all the deflex in the handle area with a gentle reflexing curve in the limb with the reflex “turning around” (headed towards the back) past mid limb if that makes sense. I’d bet any shape that you can tiller with low set and retain some reflex behind the handle will be a solid performer.

[Tommy D]

I would say aesthetically the ones that I think are the most attractive have almost all the deflex in the handle area with a gentle reflexing curve in the limb with the reflex “turning around” (headed towards the back) past mid limb if that makes sense.

Do you mean the sort of “Shrew bow” look?

     That is real similar to the one I have been using for years. My form has about 1" deflex in the inner third and the tips are glued up at 3 1/2 inches behind the back of the bow. Some of that is lost when I take the bands off and it usually ends up around 2" reflex.

Thanks - interesting that it will lose that much straight out of the form...

Would you do a tri-lam glue up all in one go? Some have suggested gluing deflex in first with a core lam and then pulling in reflex gives better performance?

Also does one do the glue up with a pressure strip? I was going to have bamboo backing first (with back of bow against the form), then a power lam, then my belly lam. Then is it worth putting some pressure strips? I was then going to cut an inner tube in cross sections to make rubber bands and then loop these over dowels spaced every 2 inches

[Badger]

   I don't do many tri lams but when I do I make them very different from my backed bows. They are deflexed through the handle and the bottom lam overlaps the handle block at the fades. I use a pressure block only at the overlapped area.

[Tuomo]

   I don't do many tri lams but when I do I make them very different from my backed bows. They are deflexed through the handle and the bottom lam overlaps the handle block at the fades. I use a pressure block only at the overlapped area.

Steve, could you please clarify? I didn't get, what you mean. What is pressure block? And how bottom (belly?) lam can overlap the handle block?

I have made many tri lams and I am also eager to learn something new!

[Pat B]

This is one of my reflex forms. I use it to temper, reflex and make corrections from twists and lateral bends. This will give me about 3" of reflex just off the form.