well I'm not the greatest wiz with software. The cheaper machines look like they have a simple protocol that I could talk with a micro controller or if it comes to it cannibalise the manual controller to simulate button presses. The more expensive machine looks like it is much more solid. Ultimately I need an XYZ table which is what any router/engraver/miller is once you toss off the head. If I try to make the same mechanism it will quickly becomes at least as expensive. With these things I just need to toss off whatever tool there is on them and put my own on the already convenient mount holes.

The more expensive one talks about MACH3 control. I thought that was a CNC program not the communication protocol. So the MACH3 controller has a USB socket so has to be driven by a computer unless there is a USB/serial driver in there so that I bypass the USB and go straight to serial with a micro controller. But as ultimately I want to computer control this as that saves me making the keypad and the display not to mention bridging with a computer anyway if I can control that USB from a VB program that is practically my solution out of the box minus the PnP head.