Increasing stack thickness

[Mad Max]

 

[Flem]

I believe the 20-25% has been the standard, at least from the 70's on.

[Crooked Stic]

  where is Roy. 

[jess stuart]

Yeah that was the point I was hoping would come to light.  Seems that building bows has several rules that are always brought up.  Not saying they are bad but am saying doing things differently isn't a bad thing. 
Remember when only osage and yew were good bow woods.  Then Paul Comstock  opened our eyes.  If we bend the rules sometimes it can be eye ooening.

[Roy from Pa]

What's yer point stickypops...

[mmattockx]

I wasn't trying to lead anyone to doing 20-25%  , just thought it would be of interest.  Folks can and will do what they want to...

I wasn't dumping on you, just pointing out that these things sometimes hang around so long that their origins get forgotten and that maybe it was only ever a rule of thumb without a hard scientific basis. If it works and the bows perform well then there is no reason not to use it. Hard won experience is very valuable and should be passed on to new guys so they don't keep reinventing the wheel.

Yeah that was the point I was hoping would come to light.  Seems that building bows has several rules that are always brought up.  Not saying they are bad but am saying doing things differently isn't a bad thing. 

Nope, not at all. Sometimes experiments are a good thing. I have been designing my first FG lam bow and am working to keep the strain fairly low on the belly side of the core wood to minimize set. Had never heard of the 25% rule of thumb before and ended up with FG at ~21% of the stack.


Mark

[buckeyebowhunter]

I'm not a math guy so forgive me for my ignorance but where are you guys getting 25%FG in a stack. If I use .040" glass X 2 equaling .080" at 25% that's a stack of .320 thousands.  For a recurve that's pulling some insane weight. Maybe talking long bows 

[buckeyebowhunter]

Never mind I went back and reread. The posts. I had skimmed through them earlier. I understand it's not a hard and fast rule.

Going to use .040 for the 65# limbs and increase taper and parallel 

[Mad Max]

.262 x 25%=.0655--.033
.040 would be what I would use if I were selling bows.
But I might grind .040 to .035 for myself
splitting hairs

[Mad Max]

I think .030 up to 40lbs. .040 40lbs. to mid 50s then .050
For me all my bows are less than 55lbs I use .040.

what stic said