Posted by lbmakem on January 21, 2006 at 13:54:24:
In Reply to: Re: Odd teeth over pin measurement posted by Steve Chen on January 21, 2006 at 01:55:17:
hi steve
my formula for helicals:
A=inv function of tvpa + (tv tooth thickness / pcd) + ((pin / base dia) x secant of base angle) - (pi / teeth).
find the angle of this involute function (A)
for even teeth meas: (base dia / cos (A)) + pin dia.
for odd teeth meas: (base dia / cos (A)) x (cos (90 / teeth)) + pin dia.
its a bit long winded but it works