The next project seizes upon the opportunity to work with a piece of industrial equipment whose price tag is far too high for me to justify spending on a hobbyist project. It is a combination of two linear stages bolted together at right angles to each other, allowing precise motion control along two axis. A configuration like this usually ends up handling the X and Y axis, so I'm going to call this the XY Stage project.

It formerly controlled the movement in some sort of inspection machine. The machine is decades old and, when the ancient DOS PC running everything died, the machine was retired rather than repaired. The old computer, associated software, and camera system were not interesting: the world has long since moved beyond their capabilities. The XY stage, however, is still perfectly functional and was salvaged for potential use in a project. Its capabilities has not been entirely outdistanced by its modern counterparts.

The control logic entry point for the system are these Parker ZETA4 Drive Compumotor modules. The design has long since been retired. However, machines built on them are still running and there's still a market for those modules. Available new for around two thousand US dollars, they are also available used for several hundred dollars. On the side of this module is an imposing looking chart detailing all the ways it can be configured. But if we can temporarily set them aside, we see the method of control are two pins: one for direction, and another for step.

ZETA4 step dir

That makes it a lot less intimidating! Control protocol for this big box is basically the same as the A4988 stepper motor driver boards popular in hobbyist 3D printers. From a system architecture perspective, this is "merely" a larger, more expensive, more durable, more precise, and more powerful cousin to the little fingernail-sized circuit boards in my 3D printer control box. It is completely within our capabilities to command such a device.

I don't know what we might be able to do with a XY stage, but I know it is too good to be gathering dust. I want to see if I can get it to do my bidding, and once I have a better understanding of its strengths and weaknesses, I'm confident a suitable project will arise.