Re: Loss of absolute position. Add encoders? Re-homing?
The only problem with adding encoders (incremental or absolute) is that with your system, and especially Mach3, there is no where to connect the encoder. Mach3 is an open loop system only.
You could replace your existing axis motors with closed loop steppers/drives or small servo motors/drives. Most modern servos will take a step & direction input and close the loop at the drive. DMM Tech servos would be my first choice.
Jim Dawson
Sandy, Oregon, USA