[camtunkpa]

Tytus,

If I am reading you right you are concernced about the motors losing index if they are back driven. I would be assuming that you are depending on the motor to only move when it get an input from the operator via a joystick or whatever....the thing you have forgotten to make your crab work flawlessly is a feedback control system.

A feedback control system would use a potentiometer to monitor the travel of your belting or chain or whatever. This potentiometer gets tied into an analog input of the control system on the machine itself.....then you can ask your programmers to make a nice little control loop to allow for a tolerance. This programming will allow the position to be monitored and the robot will adjust itself. If you are worriied about the belt slipping, monitor the shaft that allows each wheel to pivot.

Yeah and I'm normally brief about things, but I just got done taking a final on control systems and everything is really fresh in my mind. Good luck and hope to see the crab up and working!!!!!

Cliff
222 Alum.