Fan not spinning

Sorry, another newbie question.

I have noticed on my last couple of prints with pla (temp set to 205) the fan that is directed at the extruded material is not spinning. The fan on the heat sink seem to be working correctly.

Over the last couple of weeks it seemed to be working. However, when I upgraded Cura and the mini v1.04 firmware it no longer seems to spin.

Are there conditions that cause the fan to sometimes spin and sometime not spin?

Are there antagonistic step to determine if the fan hardware is working correctly?

The print quality on my current job seems good so I am not going to cancel the print just to see what happens.

BTW, what are the proper names for the fans? One seems to point at a heat sink on the extruder and the other seems to point to the material that was just laid down.

Kind of a step learning curve to 3d printing! At least I am able to design and print decent enough jigs and simple prototypes to keep me on the learning curve.


The terminology used will kind of vary from person to person and group to group I would imagine but the terms used in our assembly guide are going to be the most reliable I would think and those are the heat sink fan and the extruder fan. (So you were already pretty much spot on! :smiley: ) I also call the extruder fan a part cooling or auxiliary fan sometimes.
There are a few things I can think of that might be causing your fan troubles. I would say a good first test would be using M106 in your Cura Console. This is in the print monitor area. To access the console just click on the console button and a separate page will pop up. Punch in the M106 command along the bottom of that new window and hit enter. If your extruder fan comes on then you know the fan itself and it’s connections are all working. If it doesn’t I would start by clearing the fan out to make sure it isn’t just gunked up with hair or dust then if it still won’t turn on you could test it with an external power supply which would tell you if the fan itself was going to need to be replaced (it is a 5v fan). If it does turn on okay when you use the command the most likely issue will be something settings related. For that you could take a look at your cooling settings in the custom settings in Cura and see if there is anything that looks like it might need to be adjusted. (Or snap some photos and post them here so we can take a look since you are still getting your feet under you.)

Thanks again for the quick feedback.

I was in the middle of a 4 hour print when I noticed. I didn’t want to cancel the print to debug :frowning: The fan worked correctly when manually entering the M106 command.

After running a few more diagnostic prints it seems that the extruder fan runs when when printing a narrow element to cool the filament down and reduce sag. When printing a wide element with many side by side passes,the fan turns off so that the hot filaments remains warm enough to settle into the larger space and bond better. I guess I had just not noticed that behavior before.

As a side note, I set up octoprint this afternoon. Looking forward to moving the printer to the garage workshop yet being able to control and monitor the print from my laptop in the house. Should be able to run some ABS jobs more safely.