When showing the machine at Makers Faire and discussing the electrical interference problems a common suggestion is the original electrical enclosure didn't look correct. Too many large holes in the sides. Being made from aluminum probably isn't helping either. So this steel junction box was sourced with a trip to the local Habitat for Humanity ReStore. $10 for a decent used box for further testing. First test shows it does seem to solve the start voltage jumping across the limit switch wires but not the start voltage jumping across the drive motor wires. Next experiment is to add shields to the drive board power feed lines and also to the USB cable connecting the CAM software on the laptop.