Extruder not working properly (no clogging, no blocking)
 

Extruder not working properly (no clogging, no blocking)  

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BravoZulu
(@bravozulu)
Active Member

Hi,

I have a problem with the extruder of my Mini. It stopped extruding at all, suddenly in midprint and made strange noises.
Unload filament did not work, same strange noises. So I thought of a clogged nozzle or blocked extruder gear. After cutting the filament I could unload the filament by turning the extruder gear manually.
After disassemling I found no clogging at the hotend and no debris in the gear. It was clean.
Attempt to load filament failed, same strange noises. Extruder motor and gear just vibrated, no rotation.
I contacted Prusa via chat, explaining the problem illustrated by videos. Prusas chat partner suspected the motor to be defect. Next day a new motor was on it's way to me. Nice!

Now, Motor is replaced. Self test was succesful - But:
Same Problem, no change. Same behavior. :/

Any Idea here, before I move to the chat again?

Here the videos:

Loading attempt:

Motor not turning:

Gear and Motor manually moving:

Attempt to move via Axis Menu:

Stefan

Best Answer by bobcousins:

I'm not sure we can rule out hot end blocking, can you push the filament through by hand?

However, if a stepper vibrates like that, then it is possibly because one of the wires is disconnected. If you have a new motor, you should also have a new cable, so that probably eliminates the motor and cable. That would leave a fault on the PCB, e.g the connector is not soldered properly, or the driver chip is faulty. I would diagnose it by swapping steppers, e.g. E and Y. Note, you should only unplug/plug steppers when the power to the board is off!

 

Posted : 03/06/2020 8:59 pm
bobcousins
(@bobcousins)
Estimable Member

I'm not sure we can rule out hot end blocking, can you push the filament through by hand?

However, if a stepper vibrates like that, then it is possibly because one of the wires is disconnected. If you have a new motor, you should also have a new cable, so that probably eliminates the motor and cable. That would leave a fault on the PCB, e.g the connector is not soldered properly, or the driver chip is faulty. I would diagnose it by swapping steppers, e.g. E and Y. Note, you should only unplug/plug steppers when the power to the board is off!

 

Posted : 04/06/2020 7:58 am
BravoZulu liked
BravoZulu
(@bravozulu)
Active Member

@bobcousins

Hi.

Yes, Motor inclusive cable is new.
Swapping Stepper cables is a great idea! I will do this immediately this evening when I‘m back home. Yes, PCB is the last one, all other can be ruled out.

I will report here this evening (CEST).

Stefan

Posted : 04/06/2020 11:33 am
crawlerin
(@crawlerin)
Honorable Member

Have you tried to disassemble the whole extruder assembly? You probably did when you replaced motor. Is there anything that could block gear movement - i.e. piece of filament stuck somewhere inside or such. Do gears move freely if you turn them by hand? If there is no mechanical issue and motor is replaced, it can really be electronics.

Posted : 04/06/2020 1:45 pm
BravoZulu
(@bravozulu)
Active Member

@crawlerin

Yes, of course I disassembled all components. As I wrote above, there where no clogging and no blocking in the extruder gear. There is no filament at all in the tubes now.

So, I swapped the cable of the extruder port with the cable of the Y-port and used the „Move Axis“ in the menu to check, as suggested above. Now the failure occurs on the Y axis motor via the extruder port, and the extruder motor is working fine on the Y-port.

Video:

Conclusion: Buddy Control Board / extruder port faulty. Right?

Stefan

 

Posted : 04/06/2020 6:52 pm
BravoZulu
(@bravozulu)
Active Member

So, had a nice chat. After briefly stating the problem, results of research and presenting the videos a new Buddy Control Board should be on it’s way tomorrow.

Thumbs up for Prusas help chat!

Stefan

Posted : 04/06/2020 9:32 pm
crawlerin liked
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