Thickness t handle before adding handle

[Badger]

  Here is something that comes up a lot. This thread is not about the glue only the thickness. I think smooth on and unibond are the preffered glues but if plenty of thickness is available tightbond works fine also.

   I don't have a strict rule on this but if I were to describe it the best I could it might go like this. I want enough thickness so my handle area will not flex and pop off the handle. I want most of my fade to be made from the belly lam and not the glue on handle. I usually glue on a 8" handle piece and it usually finishes at about 6" including the partial fades.

  These are all for 50# bows. Add a minimum of 1/16" for every 10# additional weight.

 56" bow 11/16    62" bow   3/4"      66"bow 7/8"      72" bow  1".    These are minimums I use. A stronger glue may allow you to cheat a little on this.

[bubbles]

What about the minimum width of the handle at the narrowest point? I always wonder just how narrow to make my handle.

[mikekeswick]

Exactly right.
Like most things in bow making it comes down to correct design, understanding the principles involved and then executing your well designed bow correctly - not relying on this or that glue, after all most modern glues are more than up to the job of sticking a handle piece on and keeping it there.
I also read about joint creep with TBB glues and after a lot of experimenting I think it's more to do with the different shrinkage rates of different woods and/or them not being dry enough in the first place. I've tested the m.c. in enough pieces of tropicals that in the past I would have said were 'dry enough to use' now I know better but it took a while for this one to sink in! The amount some woods can shrink whilst losing those last few % is really quite impressive and also destructive in risers etc where we often glue different woods together for a certain look. I now keep my tropicals in a controlled r.h. and temp for at least a few years before using them to try and minimize these effects.

[mikekeswick]

What about the minimum width of the handle at the narrowest point? I always wonder just how narrow to make my handle.

There are quite a few variables to do with this one! Just make it comfortable  I've done 3/4 wide handles with no problems for a starting point.

[Chadwick]

And I'm seeing that these are all for stiff-handled bows. Would a slightly bendy-handled bow, with a glue-on handle area, 1) not work, 2) need one helluva glue, 3) need it to actually be a belly 'power lam' which would extend into the bending portions of the limb?

[KS51]

Funny this should come up since I was playing with some numbers on friday.  Based upon a working limb dimension of 1-1/4 x .70 inches just past the fade, if I want a handle 4x as stiff it should be 3/4 x 1-1/8, if 2x as stiff then 3/4 x 1.00, if 1.5x as stiff then 3/4 x 7/8.  Basically, the ratio of the moments will decide the relative stiffness. (these are all approximates)

B1 x H1^3 x R = B2 x H2^3    ( R is the stifness ratio, B is width, H is thickness, 1 is limb, 2 is handle)

For bendy handles, my bows work out to R = 2, stiff handles are R >= 4.

Ken

[Pat B]

Chadwick, no rigid handle will stay on a bendy handled bow no matter what glue you use. most glues we use are stronger than the wood anyway. You can use leather, cork or other bendy materials. You can also use wood on a slightly bendy handle bow if you laminate thin lams of graduated lengths that fade smoothly into the limbs.