Hi Steve

I obtained a CNEST3040T from an EBay second user which seems to have some of the components that are being used on the KX1. I have found the 3040 adequate for PCB milling at 5k rpm and have also run PCBs on my Tormach 440 at similar speeds.

You might want to consider adding limit switches to allow auto homing and also to give protection from overrun within the table and Z limits. I made some modifications to Mach3 that I found on the web to accommodate this and also for a Z height setter.

I use FlatCam to convert the CAD files into G Code.

The biggest issues in running the PCBs are the type of cutter you use and how flat you can grip the board to the mill table so as to avoid variations in depth of cut.

I have done some write ups here on my findings and there are various follow up pages. If you want some more info let me know.

Kind regards

Alan