Filament Sensor Issue
Hi all, I finished assembly of my Mk4S yesterday. The first couple of prints went through without issues. After a handful of shorter and longer prints I started to encounter problem that I'm attributing to the filament sensor having some kind of issue. The printer tries to change the filament every odd minutes for no apparent reason. There is no changing colours and the spool of filament is a brand new 1kg spool that is far from running out. After disabling the filament sensor I was able to finish the print without any issues.
I've read some things about the Mk4 filament sensor and how to clean it with pressurised air, but from my understanding this is not necessarily applicable to the Mk4S as it has a different sensor assembly(?)
I'd appreciate any help or pointers since having the sensor turned off seems to be more of a band aid than an actual solution.
RE: Filament Sensor Issue
Hi, did your sensor pass the calibration step ? Are you sure everything is really assembled correctly ?
Try to clean it, calibrate it again and if it doesnt work try to reassemble it by triple checking the instructions
RE: Filament Sensor Issue
Hi, yes the sensor passed both initial calibration and a few additional calibration steps. I'll try cleaning it with plessureised air.
As for the assembly, I'm fairly sure that it's been assembled correctly. The printer works well apart from this issue and with the Mk4s, there is no separate assembly of the sensor required anymore, so I'm not sure what I would disassemble to double check.
RE:
Ok, for the MK4S the assembly for the filament sensor is factory pre made
Following this guide, which is for the MK4 non S, try to disassemble your sensor. Just to check that everything is fine inside
RE: Filament Sensor Issue
I was hoping this issue would have been resolved with the MK4s!......
--> MK4 - MK4S - MINI+ - MMU3 - Accelerometer Guide - BambuLab A1 Combo <--
RE: Filament Sensor Issue
I had the same issue and was able to solve it. The hall sensor PCB position seemed to matter.
I disassembled everything, untightene the screw fixating the hall sensor PCB, moved it all to the left (image below) and tightened the fixating screw again.
After assembling everything, it worked properly.
RE:
Also be aware that there are two magnets inserted in the box. Only one magnet belongs to the ball and spring assembly. The second is a spare.
RE: Filament Sensor Issue
My solution described above only worked when testing via load filament function. It ceased to work the other day.
I'm going to check weather there are 2 magnets in the assembly as I did not assemble the printer by myself. If that's not the error, I guess i need to contact Prusa support because the hall sensor or the print is faulty.