[macdowswe]

I'm curious to know how you came into the 150A or 75A current specification since all the PCB software I have access too tells me 30A on 4oz stopped copper is the best you can hope for.

Well, first of all this is peak current, it will for sure not cope with 150A continuous current. Also, I think I can get a fair bit of extra heat dissipation through the heatsink on the mosfets, and down the phase wires. In the end, only testing will show what the capabilities truly are. If it turns out that it is too weak for a number of CNC applications, then it should be fairly easy to increase current capability by just increasing the size of the board and mosfets.