We didn’t get very far with a belt drive stepper Z-axis before another candidate emerged. This is the gantry of a CNC router table, with some sort of a spindle holder and two stepper-controlled axis. The Z-axis moving the spindle holder up/down, and one of the linear axis. X or Y I can’t tell. The other axis would roll on rails and controlled via belts missing from this picture.
There’s a name on the spindle holder, and a search for Inventables CNC found their current product called X-Carve which shows some superficial similarity to what we have before us. But this one showed signs of several modifications by its previous owner. We do not have the full history of it, we just knew it was a CNC project that was left behind several months ago when its owner moved to a different city. It was given to another person, who then offered it to us because we were likely to make use of it immediately on our project.
And use it we shall, because that Z-axis looks a lot better than the one we were ready to start exploring. This Z-axis module uses a leadscrew, which we expect to offer superior precision (good) at a loss of top speed (probably less important for Z axis.) It was originally designed to be a CNC Z-axis, built with aluminum extrusion beams far more rigid than the thin folded sheet metal construction of our belt-drive assembly. Our belt-drive sheet metal Z-axis was the X-axis of a Monoprice Mini Select 3D printer, which meant it was not designed to take the kind of loads that would be necessary for CNC cutting anyway.
Let’s mount this modified Inventables Z-axis and make it work instead.