I would like to use a feature similar to the "Belts and Chains" feature to create an open ended eccentric pulley system. The input shaft will be constant speed and will only turn 90 degrees. I would like to spin the output shaft with the variable speed and accurate rotation that's driven through the eccentric pulley. The output shaft will be use to drive another gear set and needs to rotate accurately. I included a simplified image that should explain the issue. I tried using "belt and chain" put couldn't use the eccentric pulley. Does anyone know any shortcuts that would give the same output? If I have to go through equations I will probably get lost! If anyone could point me in the right direction I would very much appreciate the help? Thanks guys.