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Maxime L
(@maxime-l)
Active Member
Print fan issue

Good day,

I'm having an issue with my print fan. Well, it's something I haven't noticed before. 

When I set it at around 30%, the setting used for PETG (I set it with M106 S76), the fan makes a lot of noise, but also every 5 seconds, it blows faster for a fraction of a second, then slows down again, making a "whoosh" sound every 5 seconds. I tried to record it as best as I can, the file is attached.

Oh, also, I detached it from the extruder, it's hanging freely, so the screws being too tight is not the issue.

Any idea ? A PWM problem ? Broken fan ?

Thank you.

Attachment removed
Posted : 25/10/2020 10:16 am
Maxime L
(@maxime-l)
Active Member
Topic starter answered:
RE: Print fan issue

Sorry for the double post but I can't edit my post anymore.

When I measure the red and black wire on the voltmeter, I read 2v, with a peak at 3v when I hear the whoosh sound. Isn't that supposed to be a constant 5v with the yellow wire for PWM ?? When I put the fan at 100% then it works ok and I read 5v.

I'm on firmware 3.8.1

Posted : 25/10/2020 10:30 am
Neophyl
(@neophyl)
Illustrious Member
RE: Print fan issue

Pwm will give you different average readings on a normal meter rather than the actual voltage so the change from 2-3 volts is what I would expect if the pwm value is changing. The yellow wire is the sense wire that allows the board to monitor the fan. 

Posted : 25/10/2020 11:17 am
karl-herbert
(@karl-herbert)
Illustrious Member
RE: Print fan issue
Posted by: @maximel

Good day,

I'm having an issue with my print fan. Well, it's something I haven't noticed before. 

When I set it at around 30%, the setting used for PETG (I set it with M106 S76), the fan makes a lot of noise, but also every 5 seconds, it blows faster for a fraction of a second, then slows down again, making a "whoosh" sound every 5 seconds. I tried to record it as best as I can, the file is attached.

Oh, also, I detached it from the extruder, it's hanging freely, so the screws being too tight is not the issue.

Any idea ? A PWM problem ? Broken fan ?

Thank you.

Attachment removed

The fan PWM control is not the most precise. In addition, the fan bearings can sometimes become damaged. Maybe you remove the adhesive label and put a drop of oil on the bearing. If it doesn't get better, I would replace the fan.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 25/10/2020 5:42 pm
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(@)
Illustrious Member
RE: Print fan issue

Some fans have a minimum speed; 30% may be below that threshold for that specific fan. Try using 40% to check if that setting is whooshing on you. If 40% is whooshing, try manually setting the fan to 30% and 50% without printing. If it whooshing in a static condition, probably the fan is failing.

Posted : 25/10/2020 6:16 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE: Print fan issue

I made a comparison table of the theoretical and practical values of fanspeed:

From 0 to 30% the speed curve is relatively linear, afterwards slightly irregular.

 

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 25/10/2020 8:11 pm
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(@)
Illustrious Member
RE: Print fan issue

Entschuldigung, ich spreche kein Deutsch. Was ist die x- und y-Achse?  RPM oder U / min?

This post was modified 3 years ago by --
Posted : 25/10/2020 11:41 pm
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(@)
Illustrious Member
RE: Print fan issue

Dusenlufter == Dust Lifter ... about right.

 

In any case, in I read the chart right, setting the fan to 30 is iffy at best.  M106 S50 looks to be a safe minimum with that particular fan. Important to note not all fans operate the same.

This post was modified 3 years ago by --
Posted : 25/10/2020 11:43 pm
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