It has been a while since my last update, but work on the machine has been ticking along slowly. Family and work commitments mean that I can only get the odd hour here or there to work on it. The gantry is the largest moving part in the machine. It rides back and forth on the longest axis and moves the z-axis carriage from side to side. At this stage I decided to paint the MDF using a semi-gloss paint; the machine was still in pieces at this point and I figured I wouldn't want break it up when it was finished just to paint it.

The plans are not very clear how the leadscrew should be supported or connected to the motors. I have decided to use the same skateboard bearings for the leadscrew bearing. These bearings are really designed to take forces perpendicular to the axis of rotation, but can deal with some force along the axis of rotation (like thrust bearings). The bearings are mounted in a square of HDPE plastic. The holes in the bearing mount are spaced using the NEMA 23 motor specification to allow the stepper motors to be attached eventually.