For a similar project we used the IR sensors off a USB ball mouse along with homemade encoder wheels to provide motor feedback. This method costs next to nothing and is pretty damn accurate.
It was a ball mouse which featured two scroll wheels, meaning we could recieve feedback from 4 DC motors using a standard USB interface & mouse driver.
We used the mouse buttons as triggers to mark the rotation stop points for use in the initialization routine.
The motors we ended up using were high end electric RC car motors. They were the highest torque in the smallest package we could realistically get that still fitted our budget.
It was a ball mouse which featured two scroll wheels, meaning we could recieve feedback from 4 DC motors using a standard USB interface & mouse driver.
We used the mouse buttons as triggers to mark the rotation stop points for use in the initialization routine.
The motors we ended up using were high end electric RC car motors. They were the highest torque in the smallest package we could realistically get that still fitted our budget.