Extremely loud whine from part cooling fan
I recently got my mk3 put together, and after several calibration tests and a few prints on PLA for the wife and kids decided to swap out to PET and print a few enclosure parts, spares, etc.
On my first print, I noticed that I get a relatively high-pitched, loud whine/buzzing from the part cooling fan. Is this a normal occurrence? Is it possible that there is a faulty fan bearing at play? I feel like this is significantly beyond my expectations for fan noise, as I can hear it running in the other room.
I am partway through this print at the moment and don't want to manually turn of/on the part cooling fan to test until the print is completed in case I cause issues for the print. Any guidance helpful.
Re: Extremely loud whine from part cooling fan
probably a function of the PWM(pulse width modulation) drive to the fan at reduced speed,
I have never witnessed this, probably because I am old, my hearing has lost the high frequencies, and I have tinnitus...
I understand some folk are trying capacitors in parallel with the fan motor, others are revising the firmware to use higher frequency PWM
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Extremely loud whine from part cooling fan
I sent a video to Prusa Live Chat support and they are sending out a replacement part cooling fan as potentially bearing problem.
Super helpful. I'll update if problem solved.
Thanks for the feedback, joan!
Re: Extremely loud whine from part cooling fan
Any update on whirring/whining noise? I think mine's doing the same thing.
Re: Extremely loud whine from part cooling fan
Any update on whirring/whining noise? I think mine's doing the same thing.
If the problem is new, try just lightly pressing your finger tip on the center of the spinning fan. Mine sometimes starts off oddly or will start making a buzzing noise mid-print and this fixes it. It could be something as simple as dust accumulation. Do blow the fans out once in a while when not pri ting.
and miscellaneous other tech projects
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Re: Extremely loud whine from part cooling fan
I got the same problem, It appears to be louder in low speeds / rpms.
Contacting Prusa Support.
Re: Extremely loud whine from part cooling fan
Print part cooling fan loud whine at low RPM (assuming your bearing are OK) is due to the PWM frequency scheme in the release firmware.
That particular whine is eliminated by changing two lines the the firmware to shift the PWM frequency to a less audible one. The con is slightly higher heating of the fan FET, but at the low energy levels we're dealing with, that is going to be a small effect. I've been enjoying a whine-free fan for a couple months.
see https://github.com/prusa3d/Prusa-Firmware/pull/1193/files
I don't know if Prusa will do similar in official release firmware.
If you can't edit and compile firmware, attached is my patched firmware based on 3.51. with the following changes
- part fan whine PWM fix
- 7 x 7 mesh bed leveling (only if G80 N7 instead of G80 in custom start G-code. Otherwise does standard 3 x 3 mesh)
- Fast single touch mesh bed sampling
- Corrected a slight error in Prusa Trinamic stepper wave table initialization
- Implemented experimental G-codes for Trinamic stepper tuning (M919, M920, M921, M922, M923)
These are NOT official G-codes and should not be used by most people
My patch defaults to standard values. So, should be OK unless someone tries to use these codes.
I would avoid using the experimental codes unless you understand Trinamic toff, hstr, hend, tbl and wave table scheme
That is being covered in my advanced topic
https://shop.prusa3d.com/forum/user-mods-octoprint-enclosures-nozzles--f65/fine-vertical-artifacts-trinamic-chop-tuning-any-e-t27265.html
- Indicates custom firmware is running by identifying printer as Bunny Science Mk3 or Bear Printer
Most people will only be interested in the quieter fan, N7 mesh, and faster mesh.
You will have to unzip the file to obtain the firmware hex file.
Flash as usual via USB cable and Slic3r
Most settings should survive the flash operation, just like on a normal firmware flash.
Flashing a printer is ALWAYS a risky undertaking. One could break a printer with a bad flash operation or firmware. The works well on my Mk3, but I neither guarantee safety nor usability.
Bail out is flashing back to standard firmware.