Here's a more detailed photo of the Y and Z axis components, not attached to the base:
For the electronics, I'm using:
Motors:
Software:
After a little bit of testing with this version of the machine, I found there was too much play on the various axes, especially the Z-axis.
I redesigned the Z and Y axes, and used poplar wood for the various components that needed more rigidity, so that the (possibly) final version came out like this:
To test it, I uploaded a small engraving (about 10cm wide by 6cm high) and ran the job using a piece of scrap MDF, and it seemed to turn out OK:
Hopefully this will help others out there working on their own machines. I'll post some more details later - thanks for reading!