Others here with much more experience than I have may comment, but I found it odd that he did not build any up and down adjustment in the Y axis plates. The top and bottom bearings are both fixed. Given that he drilled the holes in the Y axis plates freehand on a drill press, I wonder how accurate his spacing was.
All that said, my entire experience is with one commercial and one hobbyist CNC, so take this in that context.
All that said, my entire experience is with one commercial and one hobbyist CNC, so take this in that context.