bow wood calculation

[inksoup]

i would like to share the information about the bow wood selection calculation that i have found recently.

as you know woods have many specifications.
1 of them is moe = modulus of elasticity (higher number, stiffer wood)
2 of them is mor = modulus of rupture (higher number, harder wood)

bow wood should be low number of moe and high number of mor.

if you know those values and want to find out if this wood make a bow, then
the calculation:
the index = ( MOR / MOE ) * 1000
so for example europian yew is:
mor 15.200
moe 1.320.000
then
( 15.200 / 1.320.000 ) * 1000 = 11.515

so
if your result is between 7 - 10 then makes a bow but will not be very strong. so do not forget to make good backing. (also supporting belly with something will (may) help).
if your result is over 10 then there you go. make a bow and do not hesitate to bend it  

for eucalyptus (which i can find here easily)
17,110 / 2,049,000 * 1000 = 8.35  
and sweetgum:
12,500 / 1,640,000 *1000 = 7.62 that's fine as well.

go for it... make some calculation and start making a bows.

i hope this helps someone.

best.

note that: this calculations is just for wood it self. not laminated bow.

info from :
 http://www.wood-database.com/wood-articles/bow-woods/

[rmorris]

Good stuff Ink.

[So-Mo Archer]

Thanks for sharing, Ink. May use this as another reference when trying out new/different woods. Cheers!

[bigbob2]

great stuff. sure to be a great help to me