I have an X1C that is about 2 years old. I have replaced the extruder motor once due to it not working at all. Lately I have been having issues with the extruder motor not pulling the filament after it seems to warm. The extruder assembly is perfectly clean and grips the filament fine. I can print something after it has sat for awhile and it will print fine. Load up a second print, it will start fine, then it starts getting gaps in the print, just like the extruder motor isn’t working. I DO NOT hear any clicks like it is getting stuck. I even try to assist the filament from the AMS, but I don’t get any attempt at movement. I have a couple new motors ordered along with the circuit boards. I will try one piece at a time, but just curious if anyone has experienced this before. I have inspected all of the wiring as well, no breaks or loose connections.
I replaced the extruder motor and thought it may have been the issue, then half way through the third print it stopped moving the extruder motor again. On to the boards.
Changed out the TH board set, printed the first print fine, which it usually did. Second print started having the same issues, under extruded filament. Has anyone had issues with an SD card causing this sort of thing, or maybe the AMS is not pushing the filament correctly?
If you replaced the motor and you replaced the driver board and you still have an “overheating” problem, the next thing to change is the power supply feeding the motor+driver.
What type of filament are you printing? What temperatures? Is your second print immediately after the first or much later?
Printing Bambu PLA, different colors, different rolls, just to eliminated the filament as being the issue. It sometimes is much worse than others, just not extruding the right amount of filament, or none at all. I have seen it fail and it isn’t feeding any filament at all. Meaning the extruder motor isn’t turning, or trying to turn where you would here a click noise when it isn’t grabbing the filament.
I don’t see how this could be a filament issue. I think it’s much more likely to be an electrical issue.
Confirm that by cloning the object you’re printing so you have 4, maybe, so the print takes much longer. Do print by object if you can. I bet it still fails sometime after the 1st print completes (or that equivalent amount of time if all are being printed at once).
Symptomatically, this looks like a classic electrical problem. Something in the circuit that makes the extruder stepper do its thing has degraded and become marginal. It’s developed a temperature sensitivity. If the printer runs long enough for that component to get hot enough, it starts working intermittently or stops working completely.
This is exactly what I would to see happen if the stepper or the circuit that drives the stepper motor was failing. Except both were replaced. That only leaves the cabling and the power supply that feeds the steppers.
Cabling rarely exhibits a temperature sensitivity. If it was cabling, I think it would be more susceptible to vibration than temperature. The printer would be flakey as a function of how aggressively the printhead was moving.
But power supplies are a different story. Lots of electronic parts that can start to fail in ways that make the power supply unreliable. The result of which being the power supply can’t deliver the current the motor requires. You might hear a clicking sound as the windings get energized and try to move the rotor, or you might hear nothing depending on exactly how the power supply is flaking out.
Bambu can’t directly diagnose this with logs. If the machine was able to detect the fault, it would be reporting it already. Their only option is to send replacement parts, one at a time based on what they think the most likely fault might be, until the faulty component is replaced.
Given motor and driver board have been replaced, I’m betting the next part will be a power supply.
Thank you very much for the detailed explanation. I knew that it wasn’t a filament issue, figured I would start with another stepper motor and then the boards. I will get a power supply board ordered and report back. Just some background on this printer, it is my first Bambu, had it just over 2 years now.
You don’t have any electronics knowledge/experience, do you?
With an oscilloscope and some test leads, it’d be pretty straightforward to diagnose the problem.
So, replaced the power supply, printed two prints fine, third one once again stops taking filament. At this point I think the only piece left to cause this is the MC board. The AMS is feeding it fine, as I can watch the slack build and release, then you can see it stop taking it, or taking less.
My X1C has the same problem.When printing PAHT-CF or PC material with my X1C, the extruder motor stops working in the later stage of printing. Printing these materials requires the chamber temperature to reach 60°C, which may push the temperature of the extruder motor driver even higher to hit the 150°C overheat protection threshold. Therefore, I believe the root cause is insufficient heat dissipation on the native driver board.To resolve this, I attached a thermal silicone pad to the rear side of the TH Board, allowing the driver board and extruder motor to share heat dissipation. After running this modified setup for a period, I noticed a noticeable improvement in the overheating issue.