Last year, Cardboard Duck built a wood-glass bendy-handle flatbow, described here:
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=009791#000000
It was 61" long, 1.25" wide tapering out to 3/4" at the tips, had a stack of .570, and came in at about 100# @28".
So I want to build somethings similar, but shorter, and only 30# draw. If I plug CD's bow info into BJansen's Lam stack Calculator, discussed here:
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=007699#000000
I get a new stack of .382 for a 30# draw that is 61" long and 1.25" wide.
Here's where I want the reality check.
If I want the new bow to be 57" instead of 61" (I have some beautiful Kentucky Coffeetree lams from Troy Breeding) that would be the same as piking that 61".382stack/30# bow by 4", or a gain of about 10#s . If I then go to the stack calculator and plug in 20# instead of 30# for the desired new bow weight, I get a new stack height of .333.
Does that sound right and or make sense? Help!
I follow your logic, but if I were doing it I would assume piking it first - making the bow 110# and then sticking that into the stack calculator. Going from 110# down to 30# would suggest reducing the stack from .570 to .370.
I always go with a higher stack estimate which gives me some wiggle room to reduce weight by narrowing the limbs some if need be.
Thanx John. See, that's why I wanted the reality check. Doing it your way also works. But which is "more right"? I was thinking to go lighter and my wiggle room would be to pike the resultant bow if I needed to gain weight (to me shorter is always better)...
If I average the two results I get a stack of .351 !!
0.351 sounds good too.
Just make sure you hit that last one-one thousandth dead on, otherwise you will totally miss weight ;)
Ayup. That .001 will make or break the draw weight, I'm certain. :scared: :eek: :thumbsup: