<p>The problem is that even though the whole feed roller shaft could move freely while assembling it, it shifted at some point so that the coupler (that's only used if you've upgraded from an MMU1 setup) had moved too close to the 3D-printed housing that it sometimes randomly bound up the whole motor. This is easily fixed by loosening the two set screws on the coupler, shifting it slightly towards the motor, aligning the extruder gears again and tightening the set screws.</p>

CC BY-SA 4.0
2024-10-10T08:01:20.143Z
You might want to consider putting a nylon/PTFE washer between the print and the coupler.
0scar
CC BY-SA 4.0
2024-10-09T23:36:15.877Z
2024-10-09T23:36:15.877Z
Stuggi
<p>Sometimes, the MMU2S unit seems to bind up, and the feeder motor just sits there and buzzes when it tries to load or unload filament. I confirmed that the feeder roller with the 5 gears on it doesn't move when this happens, and I can feel the vibration in the motor.</p>

<prusa-i3><prusa-mmu>
Prusa MMU2S Buzzing When Loading/Unloading Filament
Stuggi
# Prusa MMU2S Buzzing When Loading/Unloading Filament

(Asked by: username_0 on 2024-10-09)

Sometimes, the MMU2S unit seems to bind up, and the feeder motor just sits there and buzzes when it tries to load or unload filament. I confirmed that the feeder roller with the 5 gears on it doesn't move when this happens, and I can feel the vibration in the motor.

**Tags:** prusa-i3, prusa-mmu

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## 1 answers

### Answer by username_0 on 2024-10-09. Score: 1

The problem is that even though the whole feed roller shaft could move freely while assembling it, it shifted at some point so that the coupler (that's only used if you've upgraded from an MMU1 setup) had moved too close to the 3D-printed housing that it sometimes randomly bound up the whole motor. This is easily fixed by loosening the two set screws on the coupler, shifting it slightly towards the motor, aligning the extruder gears again and tightening the set screws.

> **Comments:**
> **username_1**: You might want to consider putting a nylon/PTFE washer between the print and the coupler.  

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