Had a lot of work this week so not much time to work on the WEM, but I had a little time today to re-model the Z-stepper holder after my model blunder last weekend. Here's the new design, which will be printed Monday:

Same basic mechanics as the old version, just moved up above the focus knob instead of below. I'll be able to eliminate the clamp (which probably wouldn't have worked too well anyways) and just use 5 screws (2 on the motor side, 3 on the opposite side) to fix the holder against the microscope.