Profile coming out of form?

[nyamazan]

How much does your limb profile differ from your form profile?

What I mean does your glued up limb come out your form the same as the form itself, or is it dependent on weather you use glass or all wood and the amount of deflex/reflex or recurve of your form.

I have only built an all wood laminated bow and it took a less severe profile than my form. Maybe my method was at fault or is this the norm?

Many thanks

[Roy from Pa]

Glass will hold the shape of the form much more than wood. With wood bows, a tri lam will hold more r/d shape than a two lam bow.

[nyamazan]

Good on you Roy from Pa.

I was thinking of copying a unbraced bow to get a form profile, seems I would have to over emphasize the whole design.

There must be a whole lot of trial and error going on to get a decent shooting bow.

I wonder if anyone has designed some kind of computer generated program to get an efficient design, then again maybe that takes the craft of design away from the bowyer.

[LittleBen]

Supertiller is exactly that .... sort of. It's a decent guide.

[bamboo]

look this over----
 http://www.buildyourownbow.com/build-alongs/supertiller/
good luck!

[Crooked Stic]

More lams will spring back less as Roy said. So if you trace a profile you can build your form to compensate for the spring back. Maybe 1/4 in.on a glass bow.

[Roy from Pa]

Wooden Tri lam out of the form, and tillered to 28", you ok with that r/d shape unstrung?.. The more deflex / reflex you put into a wooden bow at glue up, the more it will have when done. Side note, Osage is the best wood for wooden bows:) The thinner your lams are prior to glue up, and the more lams you glue up together, the more the bow will hold the shape of the form. Thinner material bends easier than thicker material. It's the glue joint that holds the bow into the shape you design into your form.

     

[nyamazan]

Bamboo, thanks for the link to that supertiller, looks pretty complicated for a technology challenged person like me but I'll give it a go.

Roy from Pa, that bow looks real good, I'm assuming it's not your first!