Stepper Driver to CIM

[Chris is me]

Originally Posted by eli2410

Reason why I was avoiding stepper motors was that the design I want to do is less of a CNC machine and more of a Roomba that only does certain paths instead of covering every spot of the area. Want to make it easily programmable, so I figured making it act like CNC machine would make that easier. Steppers, as far as I knew, wouldn't be able to drive something like a robot.

This is definitely an application for closed loop speed control, and not a stepper motor + stepper motor driver. Stepper motors and drivers allow for open-loop position control when there is no chance of the motor stalling (skipping steps) or slipping. In a Roomba like scenario, the robot is driving on carpet indoors, and could potentially find itself running into solid objects that would either stall the drive motors or spin the robot's wheels in place. With a stepper here you wouldn't be able to maintain reasonably precise positioning in these scenarios.

As others have said, you can't drive a CIM with a stepper motor controller, nor can you recreate the accurate open-loop positioning of a stepper motor with a CIM.

I think the simplest way to accurately do something like this would be to use undriven follower wheels hooked up to encoders for position feedback. Properly done, these will allow for decently precise position information across a variety of different floors, and if your drive wheels slip (e.g. hung up on a small object, driving into a wall) you won't lose any precision since the follower wheels would not be moving.