stack calculator? (lamination stack/recipe)

[bsv]

How is a stack calculated? is there some kind of spread sheet or something? thanks Burt

[bsv]

sorry, I should have said Hill style bow.

[**DONOTDELETE**]

If you do a draw force curve chart on a bow measuring each inch of the draw exactly you'll see the PPI Pounds per inch varies... at then end of the draw you see the PPI start increasing. if it's jumping from 2.5 to 3" that is pretty normal. when it jumps up to 4-5 PPI that will show you se's stacking.  it makes no differece what kind of bow either.

another sure sign of a bows staking point is when the string angle coming off the limb hits 90 degrees. once it hits 90 degrees it will increase the PPI dramatically.

the stacking point on this bow was 30"
 

[fujimo]

BSV,is that to calculate the thiuckness of the stack- so you can grind your lams, in order to make a bow?
just looking at your previous posts!

[bsv]

Thanks Kirk, I think what I meant was how does one know what to use for lam thicknesses and quantity for a particular target weight/bow length, tapered or not,or combined,ect. Burt

[bsv]

Fujimo,what posts are you referring to?

[jsweka]

bsv - The short answer is experience.  The total stack of the lams and glass will depend on the design of the bow and lots of things, even in a simple Hill style bow, will dictate the stack you'll need to hit a desired draw weight. Bow length, riser length, length of working limb, limb width and how/when it tapers, amount of taper to the laminations, and weather the bow has a reflexed, straight, or string follow profile.  It's always good to take detailed notes on a bow you build that way for the next one you can keep everything the same and the only thing to change to hit a desired draw weight is the total stack of the lams and glass.

[JRHunter]

I am interested in the stack up required to build a hill style bow as well.

[jsweka]

Here's a couple builds alongs I did a while back that have what I used for stack in them. These are specific for my design and modifying that design will change the stack you need.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=004759;p=1#000000

 http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=009131;p=1#000000

[bsv]

Thank-you John

[fujimo]

hey Burt, i was referring to the awesome form build that you did- was following that- shoulda been called a drool-a-long!!
just figured your next steps when referring to stack for a hill bow, was the stack thickness to work for your new hill bow form!!