Primitive Archer

Main Discussion Area => Bows => Topic started by: Yeomanbowman on March 05, 2008, 06:54:34 pm

Title: stiffness to weight ratio
Post by: Yeomanbowman on March 05, 2008, 06:54:34 pm

Hello All,
I’m after some information, please.
I didn’t know where to post this as it could relate to shafts or lams but…
What wood has the highest stiffness to weight ratio and what is the unit of measurement?
Cheers,
Jeremy

Title: Re: stiffness to weight ratio
Post by: JackCrafty on March 05, 2008, 08:04:45 pm

Aircraft builders use this information.....and all agree that Sitka spruce has the best strength to weight ratio.
The units for stiffness are lb/in². (modulus of elasticity)
The units for weight are lb/ft³.
If you divide strength by weight, you get some number per inch (or foot).

Other woods that have good ratios:  Douglas fir, White pine, and Western hemlock.

That said......did you want this info so you could build the best bow?  ;)