Unwanted filament changes / false positive filament runout
XL was running ~fine for first couple weeks (some issues but not this one).
Prints on my XL multi-tool now repeatedly pause mid-print and trigger an un-wanted, un-planned filament change (i.e. unloads filaments and prompts for reload).
-- Has anyone encountered this?
-- Is it common for the filament sensor to detect a runout incorrectly (i.e. false positive)?
-- Any tips to resolve?
I see there is an article, "How to clean the side filament sensor (XL)", but I wanted to check in before disassembling.
RE: Unwanted filament changes / false positive filament runout
I am experiencing the same issue. It appears to be a tool head filament sensor issue for me. When loading the toolhead it takes a more than one try to get the filament to be detected.
Note in the tune section when printing (as well as settings) you can turn the filament sensor off, to get through your print.
Anyone else having this issue?
RE: Unwanted filament changes / false positive filament runout
I also had this problem and wrote to support about this.
I should follow this instructions and clean the sensor (only the part where you take out the injection-molded part with the ball and the spring and clean it), which was clean in my case. I should then replace this part with that of another extruder. That worked.
The next option would have been to clean the filament sensor on the side of the printer as the filament diameters are supposedly compared.
You can read the measured values in the printer menu under sensor info. With the problem extruder, the difference between loaded filament and unloaded filament was significantly smaller than with the other extruders. By changing the unit, the difference has increased and it has worked since then.
RE: Unwanted filament changes / false positive filament runout
How did you solve the problem Geoff? I am having this issue currently.
RE: Unwanted filament changes / false positive filament runout
What sensor did you change?
RE: Unwanted filament changes / false positive filament runout
Prusa chat support walked me through a variety of tests, ultimately determining that the filament runout sensor (on the side of the printer, nto in the print head) was at fault.
They shipped a replacement, and for many months the problem was fully resolved.
I do still get the false positives -- which is extremely frustrating given the impact to prints and the cost of the printer -- but much less often.