Originally Posted by
Norsksea
With my vacuum plate and end mill installed the original lower limit is not available anymore so I set the depth of my cut through Mach 3. I made a manual adjustment to a cut and did not have the right depth limit. I resumed the cut and before I knew it the end mill cut though the rubber seal, part and vacuum plate. Another time had a computer glitch that stalled my Z axis stepper and Mach 3 for a few seconds which sent the end mill lower than it should have. That was due to the charging circuit in my laptop. I removed the battery and no more glitch.
I made an external adjustable lower Z limit switch on the side of my mill so I can control the depth of the mill. The unit free floats on the two brackets and is locked to the spindle when the spindle is close to the desired lower limit.
I found a NOS Brown + Sharp micrometer head and used so I could adjust the lower limit accurately. The switch had a back cover that was removed and direct mounted it to the side of the base to avoid external wiring.
Frank