I think it would be cool to be able to have servos run my x and y axis and steppers for z and other.
But there are so many different varieties of encoders that it sound like a very non-trivial problem. Would you have plug-in hardware modules that talk over SPI and provide translated position information?
The servo interface would have to provide PID control, a different paradigm than what steppers use. i.e. you tell the stepper to move in finite steps-at-a-time. With a servo you tell it to move with ‘N’ amount of force.
