I have had my Ender 3 Pro for about 2 years now and it has been working amazingly!

Since November it's struggling very much while printing. I am quite sure the problem lives on the extruder motor.

About 1 of 5 prints come out ok. The main problem is that the first 2-3 first layers are all good. But as the prints develop, under-extrusion problems come. It's not a clog, because I can push the filament and it flows smoothly. It's like the motor cannot push the filament to the feeding line.

Thing's I tried so far:

  • Upgrading the extruder from plastic to aluminum (verified the tension, not too loose, not too tight)
  • Changed hotend (PTFE, nozzle, block, etc)
  • E-steps calibrated
  • Tried switching MicroSD
  • 3 different brands of filament

I noticed that the motor is getting pretty hot. I mean, you can't have your hand in there for more than a second. My theory is that this overheating softens the filament and it cannot feed. Is this possible? The aluminum extruder also gets pretty hot. There is no clicking sound or anything weird while printing, the first layers come out perfectly ok.

  • $\begingroup$ What print speed, layer height, nozzle size, temperature, etc. are you using? $\endgroup$ Jan 4, 2022 at 18:10
  • $\begingroup$ Heat affecting the filament in the extruder gear sounds like a possible cause. The E motor should not be hot to the touch, much less making the extruder hot. If this is the problem, you need to figure out why it's happening. $\endgroup$ Jan 4, 2022 at 18:12
  • $\begingroup$ Hi @R..GitHubSTOPHELPINGICE I'm using 45 mm/s, 0.2 layer height on a 0.4 nozzle, and 200/60 °C. I have been using Octopi, people says that it can make weird stuff related to the voltage. I'm investigating that right now $\endgroup$ Jan 4, 2022 at 19:09

2 Answers 2


There are a few probable causes I can think of based on your description. That it only starts happening after the printer has been running for a bit makes me think it's a heat issue.

The first problem I'd check out is that extruder motor getting that hot. It should be warm, but not so hot it's uncomfortable to hold. Either the stepper is defective, or you have the current to it set too high. There is a small screw on the motherboard beside each motor driver that allows you to adjust the current to each stepper. Find a guide for your printer to adjust it properly. You'll likely need a multimeter to do it right.

The current being too high on the extruder could also cause the stepper driver (a chip on the mainboard) to overheat. When those overheat they go into thermal shutdown and will stop driving the extruder for a moment until they cool off enough to resume. If your printer has a fan for the mainboard, make sure that is functioning properly as well. Those chips do normally get hot enough they are uncomfortable to touch, so to check if that's the problem you'd need a thermometer and to check what model they are to see what their maximum operating temperature is.

If fixing that doesn't solve it, it could be the heatsink on your hotend is getting hot enough that filament starts melting there, you can get a clog that stops the extruder from pushing filament out properly, but still feels like it can be extruded by hand. Make sure the heatsink on the hotend has sufficient cooling. After a bit of printing try touching the top of the heatsink - if it's uncomfortable to touch, you have a problem there.


  • $\begingroup$ @FedericoPerezDiduch did you get it working? I'm curious what fixed it. $\endgroup$
    – Grant
    Jan 8, 2022 at 19:55

I noticed that the motor is getting pretty hot.

That's not normal. Replacement motors are cheap and easy to find, so I'd swap out the motor before doing anything else. If the new one also heats up the same way, there might be a problem with the main board, but I'll bet a new motor will solve the problem.


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