Unwanted/interrupting filament changes during normal print
During the print of a simple part with only one filament the printer wants to change the filament in the same manner as it will be done by M600 command. But I did not define any filament changes in slicer. This behavior is anoying, because this requires an interaction on the printer otherwise the print stops - for hours?
I update the FW of the printer from 3.9.3 to 3.10.0 few days before.
Any ideas about the reason?
Printer: MK3S+ with FW 3.10.0 no MMU2S
Slicer: Prusa 2.3.3
No Octoprint involved - printed direct from SD-Card
Its is probably a faulty filament sensor. Turn the filament sensor off in the printers lcd and try again. If it prints fine then its likely the sensor. It gets a incorrect missing filament detection and so prompts to change filament. Its the same bit of firmware the machine goes through when it has a proper change filament gcode command. In which case you are going to have to adjust the sensor until it works properly. The MK3s sensor is finicky that way. There are LOTS of threads on here about the same thing and many with what you have to do to make it reliable.
RE: Unwanted/interrupting filament changes during normal print
Even though I personally haven't had an issue with the filament sensor in ages, it's certainly an option, and it has happened to me before.
I would also double check the GCODE file. Open it in a text editor such as Notepad or Textedit, then search for M600. It's very easy to inadvertently add a filament change in the slicer preview by accidentally clicking on the vertical scroll bar.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
I agree probably an IR sensor error
There are numerous posts regarding this issue, my thoughts would go with the sensor adjustment. If the IR sensor is reporting, even momentarily, end of filament, then it may move the mmu to the next slot. That can be turned off so that you get the error but just refeed the filament. I believe that that the munu item is join filaments yes or no.
Stay safe and healthy, Phil
Checked file for M600 commands
@Neophyl
Thanks a lot for yout hint. I checked it using notepad.
I found one M600 command very close to the end of the file - but the complete line is marked as coment. See below
---
; color_change_gcode = M600
---
IR-Sensor
@fuchsr and @pcweber
I will have a closer look to the IR-Sensor.
Several months ago I attached a MMU2S to the printer but was not statisfied with the results thus is removed the complete MMU2S including all electrical connections. The only thing that remains unchanged is the filement sensor - and yes I also changed to the firmware w/o MMU2S support. But your right the filament sensor seems a little bit tricky.
If this happens again I will have a closer look to the sensor. Thanks a lot for your help.
Check the connectors, a loose plug may vibrate and give a false report.
Cheerio,
RE: Unwanted/interrupting filament changes during normal print
I had the same problem on multiple Prusa MK3S after upgrading the firmaware to 3.12.2.
They worked fine before, after the upgrade all four of them had this same problem. No mechanical changes, no MMU involved, no M600 in the gcode.
It was independent of the slicer, the 3D-model and the SD Card.
RE: Unwanted/interrupting filament changes during normal print
Ditto- I just upgraded to latest FW (6.0.0) on my MK3, started giving filament change commands every minute!! read here disabled Filament Sensor its printing for 5 mins so far no filament changes commanded- Is it the FW or my Sensor is defective!?