S3 Fan noise when printer is idle

[jeremymorgan 3]

I have a brand new S3. After the printer boots up and is 'ready to print' (idle) I notice quite an annoying high-pitched whine from the front (axial) fan. It's not particularly loud, but is annoying in a quiet room if working near to the printer.

 

When the printer is idle the fan is disabled so the fan blades are not moving - the fan is stalled.  The noise I can hear is coming from the fan motor. I asked my supplier to send a replacement fan, and I have fitted this but it has made no difference. I measured the voltage across the fan in this idle state and it is around 2.3V. I would have expected it to be lower. I think that this is the problem - as the idle voltage is not zero the fan is trying to start but the voltage is too low so it is unable to do so, and it is generating the noise. The fan works OK when printing by the way. Interestingly, if I rotate the fan blade a few degrees with a screwdriver the noise stops, but then returns when the blade springs back to its resting position.

 

Anyone else noticed this? Maybe a firmware update to set the idle voltage lower could fix it? I believe Prusa had a similar issue with a fan driver that was fixed in firmware.

[DemonicYoshi 6]

I have the same exact issue, I've been turning the printer off when its not in use because I have sensitive hearing and the high pitch is very annoying to me. If this can be fixed via a firmware update I would appreciate it very much.  

[gr5 2,173]

If both of you go through this link and request a firmware fix (surely the firmware can disable the fan completely (looking at the schematic) then maybe you can get a fix in the nest release of firmware:  https://support.ultimaker.com/hc/en-us/requests/new

 

[Dim3nsioneer 557]

You guys are sure it's the fan and not the enabled xy stepper motors? There I hear such a noise. But if I perform a homing through the menu, they are disabled and the noise gone.

[gr5 2,173]

circuit diagram for reference.  Fan normally sits with 5V on pin 1 and pin 2 is open (I assume pin 0 is not used).  So both sides of fan should be at 5V when off.  Inside the fan is a fancy circuit (I believe) that detects rpm and pulses the wiring accordingly with circuitry inside a chip inside the fan.  I think the sound is coming from that circuitry trying to get the fan to start up but it can't because the voltage is too low.

 

What seems strange is that the fan is getting any power at all as I would think the firmware would keep Q1 turned off (when Q1 is turned on it grounds pin 2).

 

It could be that the firmware is not at fault and some part is broken (Q1 or D1 most likely) but I suspect it is a firmware thing where it is sending a small amount of power to the fan.

 

[gr5 2,173]

A friend checked and it's 2 wires going to the fan so the ground pin (J1 pin 0) is not used for these fans

[wdwms 2]

Got the same issue here. If you blow on the fan to make it spin you can hear the sound change.  Any word on a firmware fix?

[CarloK 203]

@jeremymorgan @wdwms @DemonicYoshi This forum is for users helping each other. When you want Ultimaker to take action, then use the support link posted by @gr5.
By coincidence I see this topic and created a ticket for you guys.

 

Being curious I also had a look into the problem and I think I found the problem. A led driver chip is used for the LEDs in the print cores and a few spare pins are used for controlling the fans. The LED's brightness can be controlled from 0 to 99.6%. The fan function is inverted and ranges from 0.4% to 100%. This means the fans are always a tiny bit on and that might be what creates the noise.

I'll test a firmware fix this week. No promise on when it will be released.

[wdwms 2]

@CarloK  Many thanks for looking into it. Yes i would have opened up a support ticket if you didn't pick up the thread. Much appreciated that you started it on our behalf.  I need to open another one, my Z axis started making an odd noise when getting ready to print.

 

If it helps, I don't recall having the fan/sound issue prior to v7.

Thank you!

[CarloK 203]

@wdwms Weird that you mention this wasn't noticed prior to v7. We are talking about the fan in front of the printhead, right? Not the two fans on the side of the printhead?
The front fan is driven by a low level routine and hasn't changed in 4 years.

[wdwms 2]

@CarloK Correct, it's either it wasn't doing it before 7 and a little bit into 7.. and by that I really just noticed it this weekend. So, wondering if all the printing finally wore the fan to a point where it is less tolerant. That is, its now broken in so that little bit of voltage can move the fan ever so slightly, the magnets pull it back.. repeat this over and over at 60hz and you get the buzzing.  The bushings "new" out of the box may prevent this oscillation; but after hours of printing it reaches a point where the issue surfaces.  W/that said, I only got my S3 2-3 months ago, i'll get you total print time if you'd like.

[CarloK 203]

Our intention was to have no voltage on the fan when off. I think we can fix this with software but didn't get to test this yet.

[jeremymorgan 3]

On 11/30/2021 at 8:21 AM, CarloK said:

Our intention was to have no voltage on the fan when off. I think we can fix this with software but didn't get to test this yet.

@CarloK Did you make any progress with this? Do you think it is possible to fix it in firmware?

 

Every time I update my S3 with latest firmware I have had my fingers crossed hoping the fan idling noise will stop!

 

By the way I opened a support ticket for this: #14701 then #23846 to follow up.

[Framar 38]

I have the same issue too my my S3. Hopefully it's going to fix soon.

[CarloK 203]

A firmware fix has been proposed and is high on the backlog, but it has to compete with many other tickets. It's now planned for v8.1, end this year, but don't take this as a promise, it only means it will not arrive earlier than this release.

[mikebuss 1]

Is there any update on what release this will go into? I have had the same issue since buying the S3 a few years ago. Thank you.

[cleverhans 1]

Another owner here, I can't stand having this printer on in my office because of the loud idle fan.

[CarloK 203]

@mikebuss, @cleverhans: I already posted an update on progress, which is more than we normally do: The problem is known and we hope it can be fixed with a software change, this is not going to happen before end of this year.

This forum is for users helping each other. Some Ultimaker employees, like myself, do visit here occasionally but our powers are limited. Priorities for planned work are, amongst others, determined based on the number of user reports.
You can get a bug or feature on a higher priority by reporting to https://support.ultimaker.com

- Choose the 'Support' button on the lower right

- Select ' Get in touch'

- Select 'Leave a message'

- Select ' Hardware enquiry'

- Enter your problem description or feature request

[gr5 2,173]

@CarloK - are you still at UM?  I think you should be able to answer this regardless.  I've seen people who have trouble with active leveling failing due to noise (fails the noise test) and they fix the printer often by changing a side fan!! Which is "off" during leveling.  Now it could be acting as a passive antenna with it's coils and such but is it possible that the side fans are also slightly "on" when they are "off"??

 

If so, then this is extremely important - your simple fix to completely turn off the fans (all 3) should get implemented as soon as possible as it is causing a world of hurt for some people.

[CarloK 203]

@gr5 I'm sorry to say I'm no long part of the UM organization. 😪

I tried to get attention for this ticket but I wasn't part of any of the teams working on the S-line of printers (I was mr. UM2+ Connect). I don't know the current status for the ticket, perhaps @robinmdh can give an update?

[gr5 2,173]

But @CarloK do you happen to remember if this problem was only for the front fan?  Or if it was for the front and also the side fans?

 

[CarloK 203]

@gr5 The front fan is a different type from the side fans but the electronics circuit is identical, so I suspect the side fans to have similar noise problems (electrical and audible) as the front fan. It's just that these problems might be more notable on some batches than on others. For the front fan we know there was one batch with more audible noise than earlier batches, but results will vary per individual printer.

[DemonicYoshi 6]

I already gave up on this ever happening. However, I upgraded my firmware today and afterwards the noise from the printer was gone. 
I then went into panic, I must be experiencing hearing loss as I no longer can hear the hum of my printer's fan noise when idle. To restore my sanity, I checked the firmware update logs and to my surprise "Fixed the situation whereby the print head fans were turned off but still kept making electronic noise" was included in the fixes.  

Therefore, I would like to thank everyone in this thread who helped make this a reality. I appreciate the effort everyone put into making this a reality, our ears can now experience quietness again.

 

[gr5 2,173]

yay!!

[robinmdh 100]

we mostly have @CarloK to thank for this, he made this fix before he left😞 ultimaker !!!!!