Notifications
Clear all

filament issues  

  RSS
Jason W
(@jason-w-2)
Member
filament issues

My son has the MK3 model and mid print it will just stop and the filament will unload. He is also having the same problem when loading the filament. It just stops and unloads. Any suggestions as to why or what I can do about this? Thanks.

Posted : 11/01/2026 8:58 pm
vhubbard
(@vhubbard)
Reputable Member
RE: filament issues

When the filament sensor singnals it ran out of filament it goes into unload/reload mode. This is the behavior when the printer thinks the filament has eneded. It may may have debris in the IR sensor area, IR sensor loose, bad wire to IR sensor, bad IR sensor connection and so on. See the PRUSA MK3S online assembly instructions for the E-Axis to see the assembly. If there is an MMU involved, there is a filament sensor on it also that may need to be calibrated.

Posted : 12/01/2026 11:20 pm
Diem
 Diem
(@diem)
Illustrious Member

If this is happening with all prints then first check that the filament sensor connection to the Einsy board has not come loose - in fact pull and reseat all the connections there to ensure good, clean, connections.

Come back if the problems persist.

Cheerio,

Posted : 13/01/2026 2:03 pm
Share: