Need some help from the "Hill Style Gurus"..

[TX FLY CASTER]

I am wanting to build a Hill style bow ,64" -66". I need riser overall length and also the proper handle length. I have built several of the 68" straight limb LB's from Binghams plans but the riser seems much longer that a typical Hill design. Seem like the right place to ask there are many talented builders on this site. Thanks in advance!!!!

[typical2]

I make my risers between 12 and 15".  I want my handle area around 4-4.25". If you use your current form you will simply need to shim above the air hose to maintain the appropriate gap.

[canopyboy]

Originally posted by typical2:
I make my risers between 12 and 15".  I want my handle area around 4-4.25". If you use your current form you will simply need to shim above the air hose to maintain the appropriate gap.

x2. Well, I haven't gotten down to 12" yet, but I like the results with risers about 13-13.5" for a traditional handle, and closer to 15 for a forward handle. 4-4.25 is right on for handle length.

[TX FLY CASTER]

The plans for Bingham's 68" straight limb design call for an 18" riser. If I shorten it to say 16" or even 15" what needs to change in the lam stack?

[typical2]

You could lose a couple pounds of draw weight.  I don't think it will make a huge difference.

[TX FLY CASTER]

With the handle at 4" it seems like the shelf would be cut @ 2" above center? Seems like the tillering work be a lot of work........lol.

[typical2]

I place the center of the riser 3/4" below center of the bow.  I place the shelf 1.25" above center.  Top limb ends up being a little longer than the bottom and usually gets me the 1/8" positive tiller I look for.

[canopyboy]

A good first order estimate on lam stack with changing riser length is to think of the working part of the limb. If your riser gets two inches shorter, each limb gets one inch longer. Take the ratio of the working limb lengths (fade to string nock) and use it to adjust your stack.

Example - 68" ntn bow, moving from 18" to 15" riser: Average working limb length originally 25". New length is 26.5". Ratio is 26.5/25 or 1.06. If your original stack was 0.500, your new stack to maintain the same weight would be 0.500 * 1.06 or 0.530".

I also offset my riser with the top limb being longer, but not by as much. I cut the shelf at 1-7/8" from riser center, or at the top extent of the handle area. I don't think tillering is any harder than any other bow.

[TX FLY CASTER]

Ok the whole riser below center is throwing me off. Are you placing it in your form below center or marking below center on the layout once it comes out of the press?

[typical2]

I cut my air hose form out so the center of my riser is 3/4" below center.  There are other ways to do it though.  You could just center the riser and then cut the shelf in 2" above center.  Mainly personal preference.

[TX FLY CASTER]

Ok,I see the concept , the actual center of the bow ntn would be above true center (after positive tiller is acquired. Which could be done by shortening the bottom limb.