I have my MPCNC completely assembled and have begun testing by plugging in the stepper cables that came with the moters about 30" long. Everything works fine at these lengths. I have tried making some extensions to try out longer lengths. The extensions are probably 12ft long. When I add the 12ft extensions the steppers make a lot of noise. My extensions are 22AWG braided cable unshielded. I soldered the mail connectors and crimped the female dupont connectors. I don’t need 12ft extensions probably more like a total of 8ft of wire. My conduit lengths are 30.5 inches. I wanted a 2ft X 2ft working area.
So my questions are there limits to the length of extension? Do I need to use shielded cable instead of unshielded cable? If using shielded cable do I need to tie the shield to ground on my controller board? Does it matter whether you use twisted pairs for the cabling?
I am using a Makerbase MKS 1.5 board. I have adjusted the steps per mm to match my board.
There are some practical limits (like multiple 10’s of feet), but you shouldn’t run into them if you keep the wiring less than 15 feet or so. Unshielded should be fine for most things (excepting plasma cutters). Infrequently, folks have seen some anomalous behavior with end stops due to noise.
When you say the steppers make a lot of noise, is it louder than it was before you added the extensions? I can only suggest you make sure the connections are good and also check the current from the stepper drivers. Ryan’s got some info about how to set the stepper drivers up properly if you haven’t already done so.
My machine is good for a full 22" X 40" (physical size is 4’ X 3’) and I managed with just the extension wires that Ryan shipped with my kit. In fact I could do well to shorten some of them actually. They were relatively inexpensive and I never have trusted my connector making abilities so it was the right choice for me. When I do shorten them I’ll just be cutting and soldering the wires mid-span.
So I cut off the Male ends on my extensions that were just soldered to make pin header segments and replaced them with crimped dupont Male connectors. That seems to have fixed the issue. I have one 12-13ft extension working and one 8ft extension working. I am surprised that this would resolve this.
I am going to have a go at a couple more cables in the next couple of days but I think the crimp on option is going to work well. With this solved I can actually start routing the cables the way I want them to give the machine the finished look.