Stepper motor wire causing interference
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I think I saw a review on YT when this (or similar) problem was shown. In most extruders stepper is isolated from other parts. With hemera all is ALU, so there is a connection between motor and the thermistor housing. I would try to grounding hemera.
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I suggest using shielded cable for the MFM if it will be running next to a stepper motor cable. Alternatively, use 4 core shielded cable for the stepper motor.
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@Phaedrux forgive my ignorance, but you are literally just doing a braid of the existing wires like you would long hair?
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@Walternate thats how i braid mine
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I do mine as two twisted pairs, twisted together. So the two wires for each coil are twisted together and then those two sets are twisted together. No idea if this is any better/worse than braiding them all together though.
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@gloomyandy I've done both. It's easier and faster to twist the two wires of a phase then it is to braid. I haven't had problems with either way.
The physics of it all is pretty complex and interesting. I had a good link for it a while ago, but can't find it now. But here's one that covers most of it. https://www.dataforth.com/protecting-signal-lines-against-electromagnetic-interference.aspx
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Man, thank you everyone so much. I appreciate your responses and the time you took to do so. I am going to first try the braid/twisting, then will go to shielded if I have no luck there. Thank you again!
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Okay coming on back for anyone reading this with possibly the same issue. The suggestion of twisting the wire pairs looks like it has fixed the issue so far. I have a 6-wire stepper cable that adapts on down to four to the Duet. I took an extension out since I really didn't need it, then popped the wires out of the molex connector two at a time. I then twisted those, putting them back into the ends when done. I ended up with 3 twisted pairs.
Hooked everything back up, have run 3-straight days of prints and am back to boring flat temp lines and the MFM hasn't errored once. A HUGE thank you to the people who gave suggestions, they were right on. Thank you all!!
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I've run into a similar problem, came here looking for answers. I'm converting a cheap xvico printer to a duet 3 board. (yes, the board costs more than the entire printer, but it'll work!)
I only have the X and Z steppers connected so far, and the X limit switch. It already wont home properly. I found the limit switch is bouncing erratically when the stepper turns on.
I thought I'd try twisting the stepper wires together, as suggested here, but I look at my printer and find it's using a 6 conductor cord to each stepper. 4 wires for the stepper and 2 more for the limit switch, bundled nicely in a black cord.
I'll replace these wires. A few alligator jumpers to the limit switch and it works properly now.
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@lorenzop said in Stepper motor wire causing interference:
I found the limit switch is bouncing erratically when the stepper turns on.
see this marlin page about hardware solutions for that.
https://marlinfw.org/docs/hardware/endstops.html