I'm curious, how does one add a powered rotary table to the controls. I'm toying with adding it to my new router mill to do engravings on round objects with a salvaged printer motor. Help.

What type of drives sre you using? If your set-up allows(hardware and software) you to have a 4th axis, then it is simply a case of add the hardware, tell the software it has 4 axis, oh yes and of-course all the necessary building/wiring ....integrating is always fun...;)

Could'nt I use y axis as a control on Mach2. ? Isn't it just a different way of looking at y axis. Like rolling it up instead of spreading it out flat?

If you are using Mach2 is already has axis' a, b and c which can be programmed as rotary axis. I think it would be much easier to use on of the rotary axis and just not use you y if you don't actually need the 4th axis.

Mike