Replace 18/4 Stepper Motor Wire

Hello all,

I am going to replace the original stepper motor cable wire because I need it a little longer. Probably adding about 5 ft to each run. I am wondering how important the “shielded” wire is and should I stick to 18ga. Would there be any reason to move up to 16ga?

Any recommendations would be great and if I can get the wire from amazon that would be even better.

thank you


Using Shielded wire is very important to prevent electrical interference, especially when adding length. Having wiring of this use running together in confined areas such as a drag chain will introduce electrical “crosstalk” on to adjacent wires by induction, causing unwanted “ghost” movement of stepper motors. The shield on the wire helps to prevent this by providing a path to ground for these unwanted signals. Make sure to connect the “drain” or shield to ground on only one end of the wire, though, normally on the controller side.

As far as using 16ga vs. 18ga wire goes, if you have plans in the future of upgrading to a higher current stepper motor system, this would make sense to do 16ga wiring now so you won’t have to do it in the future.
Otherwise, for the present current draw, 18ga wiring is plenty big enough for use when adding only 5 to 10 ft of length.

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Thank you very much! Sounds like 18ga wire is going to be fine then. Do you have any suggestions on where to get the wire? I noticed inventables isnt currently stocking it online. Would this 18/4 wire I found on Amazon work well?

Yes, that will work fine. Watch for the wiring colors, though, as they will be different than normal (red, black, white, green)

If you need to get it quickly, you can check Home Depot. They do sell 18 and 16 gauge shielded wire as well by the foot.

when you talk about connecting the drain to ground on one side, where are you referring to grounding that? I do not have the X-controller, I have the previous version of the x-carve controller.

When you connect the wire to the driver side (motor driver or controller, not the motor itself), you connect the shield or drain wire to ground.
Leave the motor end of the shield disconnected. This way, it will act as an antenna, allowing extraneous signals to be captured by the shield and taken to ground.

If you connect both ends of the shield to ground, your shield drain will not operate properly.


You want to connect the shield or “drain” wire directly to an electrical ground. Do NOT connect it to the stepper motor wires in any way.

It’s purpose is to carry any extraneous signals away from the stepper motors in a harmless manner. This requires the drain wire (or shield if you prefer that term) to be connected on the ORIGIN side (closest to the controller) directly to an electrical ground. The DELIVERY end (or end of the wire closest to the stepper motor) is to remain free floating, and not be connected in any way. This allows the shield to act as an antenna, and carry those unwanted signals away from the motors and the controller.

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