So I’m walk into my office to another printer that just failed. I assume it’s the nozzle that’s broken again so I start taking apart and putting it back together as usual. But when I try to load up new filament… To my surprise it’s actually the motor that’s brokenBecause instead of spinning clockwise it’s twitching in place. Cool so I’ll just order a new motor… The new motor had the same problem, twitching in place. I thought it might be the extension cord so I took it out and plugged the motor directly into the printer… and like a cartoon it started to work perfectly but in the opposite direction. I believe it’s the extension cord but I couldn’t find one online and I wanted the experts opinion on it before I buy another thing.
[F I X E D] I switched the wires and the motor started spinning in the right direction. Thank you so much for helping me fix my printer: Cobalt Griffin, Fix3r and Jim. Once again seriously… THANK YOU
Are the connecters in the wrong place?
Chances are it's actually one of the crimp connectors at one end of the extension wire, the twitching thing is usually caused by a couple cables being flipped in the pinout. Stepper motor plugs have open secret that not all motors use the same pin-out, so plugging the cable from one motor into a different one has a 50/50 chance of working. Fix is to look closely at the extender, if two of the cables cross at any point, that'll be the culpret and you'll need to remove that cross-over to get it working.
Why would he need to swap crossed over motor leads?
Are we not assuming that the printer was operational before this?
The motor leads were either un-twisted or twisted when the print was started, but when he got back to the office they had magically swapped... i don't think so! (unless a poltergeist did it)
He already said that the motor turned the wrong way when connected direct to the board without the lead, so on this occasion we can deduce that the lead has a twisted pair and that untwisting has the effect of changing motor direction!
But i do concur given the limited useful info from OP that the most likely issue is damage or poor connection of the motor lead!
Is it even the factory extruder?
A twitching motor is either insufficient torque (driver current),
Intermittent connection (damaged lead or headers)
Filament path blockage (and the motor doesn't have enough torque to break friction on the filament and start grinding!)
Failing stepper driver (reducing current supply to stepper giving appearance of under torque)
Heck, could be the hobbed gear grub screw come loose and the 'twitch' could be as it just snags on the flat spot of the motor shaft whilst spinning!
Swapping the motor to a known good cable is to check that it is the wire and not the motor.
Any suggestions on how to remove that cross point. Like do I need to twist it in certain way or do I need to cut one of the wires?
Just looked at my Ender 3. My wires are twisted (looking at my E0) and the machine is running fine. I like CobaltGriffon's suggestion. Plug another motor into the cable and see what happens. And go from there. I had my E0 motor go bad and just plugging in my replacement resulted in the described twitching. It resolved when I correctly rewired the connector. There are plenty of tutorials that describe how to do this.
Haven't done it myself but supposedly it's possible to back the pins out with a push-pin or something equally pointy. Personally I use the dupont male to female jumper lines you can get for bread-boards to create a mini-patch cable that swaps it back at one end, much easier to do and won't damage anything :)