Unwanted/interrupting filament changes during normal print
 
Notifications
Clear all

Unwanted/interrupting filament changes during normal print  

  RSS
Robert4711
(@robert4711)
Active Member
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

 

 

Posted : 06/09/2021 12:19 pm
Neophyl
(@neophyl)
Famed Member

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.

Posted : 06/09/2021 12:54 pm
fuchsr
(@fuchsr)
Noble Member
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. 

Posted : 06/09/2021 7:56 pm
pcweber
(@pcweber)
Estimable Member
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...
Posted : 06/09/2021 8:17 pm
Robert4711
(@robert4711)
Active Member
Topic starter answered:
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

---

Posted : 09/09/2021 1:30 pm
Robert4711
(@robert4711)
Active Member
Topic starter answered:
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.

 

Posted : 09/09/2021 1:39 pm
Diem
 Diem
(@diem)
Noble Member

Check the connectors, a loose plug may vibrate and give a false report.

Cheerio,

Posted : 09/09/2021 2:48 pm
Share: