Part Cooling Fan, does not work while Printing

What is the problem?
Octoprint fails to start the part cooling fan while printing.
If the printer is Idle, it starts from Terminal (using M106 S255)
If I print from SDCard the fan works just fine.
The problem started two days ago. Before that, the part cooling fan worked like a charm.

What did you already try to solve it?

  • rebooted Octoprint
  • printed in Octoprint Safemode
  • rebooted printer
  • used different slicers / models / gcodes
  • used terminal to send M106 S255 while printing

Logs (octoprint.log, serial.log or output on terminal tab, ...)
octoprint.log (53.2 KB)

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, ...)
OctoPrint 1.3.11
OctoPi 0.16.0
Raspi 1 B+
Anycubic Chiron, V1.3.0

As you have discovered, the part cooling fan is controlled by the GCode commands M106 and M107. OctoPrint can control the fan when you are not printing, but once you start a print, the GCode commands will take precedence. There are plugins that can alter this behavior but it doesn't look like you have any installed.

Using a text editor, you can search the GCode file you are uploading for M106 and M107 commands. As a test, upload the following through OctoPrint and print it. You can also put it on the SD card and print it from there as well. Results should be identical.

fanspeedtest.gcode (187 Bytes)

Hey there

thanks for your replay b-morgan and thanks for that speedtest.
It did the same errors as before with that script but since I tested all day I found out it sometimes also occurs while printing from SD-Card, so it seems like a non-octoprint problem.

But thanks for helping!

Have you checked for loose fan wire(s)?

1 Like

Yes, I checked for continuity from the FAN0 Connector on the board to the fanpins of the mainconnector at the hotend aswell as the connectorboard in the Hotend.

Connectionwise everything is fine.

After contacting anycubic support, they told me it's possibly a bad mainboard, hope they'll send a new one :slight_smile:

Thanks for your help!

Good afternoon marco3993
Did you ever resolve this issue? I have recently purchased the Chiron and am having exactly the same issue. I can't figure out why as the fan GCODE is present but it just seems to ignore it.
Strangely i also can't print from the SD card as it randomly stops.
I've got a case open with Anycubic but wasn't sure if you managed to fix this.

Do you have some example gcode from your manufacturer? Just to rule out any other errors. If you got a example gcode try to print it via sd card. If it still not works I would contact the manufacturer.