Hello,

i want to set up a smath sheet for gear calculation and i need the involute fuction for an angle. How can i implement the involute function in the sheet?

invαwt1=2*(X1+X2)/{Z1+Z2}*tg(α1)+ inv αt1
a12=ad12*cos(αt1)/cos(αwt1)

X1 and X1: addendum modification coef.
Z1 and Z1: Number of theets
α1: normal pressure angle
αt1: real pressure angle
a12: gear distance


Temporary solution:
invαwt1=2*(X1+X2)/{Z1+Z2}*tg(α1)+((tg(αt1))-αt1*π/{180*'°})=0.06294
and then choose for 0.06294 the angle value from a printet "paper" table


Regards Alex

Hi Alex -

I just posted a snippet I use for inverse involute calculation, you can find it at the below link:
http://en.smath.info/forum/yaf_postst7534_Involute-Function.aspx

It's an iterative method that finds the inverse out to 10 decimal places.

Hope it helps.

Dan