Thanks Liam for the much in-depth response. My questions was born out of what I have experienced in AUDIO circuits; the noise from LED lighting can make loud buzzing noises that even the best shielded cabling can not resolve. My question was based on that experience and that some people of had issues with EMI on CNC machines. I am happy to report on both my Shapeoko and my Millright machines, I have not experience issues with interference.