First off thank you again for taking your time to help me work things out and it is greatly appreciated!
Got a response from SM support but they are not understanding my explanation, odd because my wife is Chinese and I work on Nuclear power plants in China, just joking! Hehe.
They think I’m talking about the noise you hear with physical interaction between the nut and linear screw and not EMI.
Thank you for reaching out to us.
This noise is caused by the relative movement between the screw and the nut and the sound is amplified in the linear module cavity. Here I offer two videos that show you the noise, which cannot be avoided.
We have innovatively adopted the CAN (Controlled Area Network) bus expansion solution, which was widely used in car automation. Rather than adding more ports and make a bigger control board with tangled cables, we’ve upgraded our controller to expand your creativity by providing universal ports, multiport adapters, and a CAN Hub for adding additional CAN-bus ports.
In conclusion that the noise will not affect the print quality and it will not appear when you are printing.
If you have any other questions, please feel free to contact us.
While CAN Bus is nice you still have to account for EMI so unless their employing some super duper filter in the CAN or compensating for it in software it will be present and have affect on the mother board. As for your question about the metal casing not unless you had a drain wire from shielding using it as a grounding point which the motor does not.
My files are my own I designed it fusion 360, what files would you need to look at stl or gcode and how do I get it to you?