Yes I am not planning to use FR4 at the moment due to the extra wear it puts on the tools. All the stuff so far has been SRBP. I will use a vacuum cleaner close by the miller if I plan on using fibre glass board.
Thanks
Development on the miller has temporally stopped because I am now on with the project that I built the miller for. When that is done I will finish off the design and put it on line.
Are these compatible with the code for cool drivers you used (step and dir pins?)
Yes most stepping motor controllers have step and direction pins.
how were you planning on implementing limit switches
Limit switches and motor control are on a MSP23S17 port expander.