the eccentric rod and constant length rotations thereabout, are hard coded in the shape sheet cells.
So far I am using sheet references that lead all the way back to the main drive wheel's angular rotation.
Then coded in VB to rotate the main drive wheel.
I found the expression for calculating angular movement within a scalene triangle -> Cos(theta) =( A^2 + B^2-C^2)/(2 x A x B)
to be helpful for the minute.
(work in progress).
on menu press "forward"."reverse" "stop"
;)
cheers
Cliff