Why does PlasmaCAM use servo motors instead of stepper motors?
It’s true that this machine could be made a lot cheaper if we used stepper motors and drives instead of high-tech servo motor systems. But when it comes to something this critical, quality cannot be compromised. Experienced machine tool users know that servo motors are vastly superior to stepper motors, because newer, high-performance machines (like CNC mills) use servo motors, whereas older, more troublesome machines used stepper motors. Yet the real reason for the performance difference requires some explanation. PlasmaCAM’s servo motors use optically-encoded feedback, so the controlling software always knows the true position of the machine. A simple stepper motor controller must “trust” that the motor has moved exactly as requested each time a step current is made. Without feedback, the controller cannot identify and correct whenever the motor misses a few steps (like during jolts, vibrations, hang-ups, etc). Since a single shape may require millions of steps to trace, errors in po
