Weird hissing sound at print pause

[NBull 14]

Hi, I had to pause a print for some hours today, I know it's not advised to do print quality wise. and its a really long time since I have don it last, so don't remember if it's normal. 

 

After pausing the the print, the head moves to the front side cools and shut down the fan. normally. 

After the fan have shout down theres still this weird hissing sound coming from the printer, that I can't locate wheres coming from.

 

It doesn't sound like a fan, its more like a hissing / humming sound.
but still quite loud.s5 sound video.mp4.zip

 

It is possible that the sound is there all the time when printing, but that it just cannot be heard for the fans.

Is this something I should be worried about and why doesn't it go away when the printer is paused?

 

ps. bed temp is set to 0c printing on tape.

[Smithy 1,144]

Maybe I am wrong, because I don't do it often, but normally when you pause a print, the print core remains at temperature, or not? And if it remains on the temperature, then also the front fan runs. And for me it sounds like a fan, but that could also be caused by the video.

 

BTW: You should clean your Z-screw 😜

[NBull 14]

The print core do cool down and all three fans in the head shuts off (min do anyway, can't say if its normal?)

As fare as I can tell the fan from the electronics down next to the power cord also goes into idle. don't know if there are other fans on the printer.

 

 

(fan bracket is only open to show that the fan have stopped when paused. also the two on the sides has stopped, can't take a photo of that though 😉)

 

I wouldn't say that the z-screw is decidedly dirty?, maybe it's the video quality. if you are referring to the dark color it has always ben that way.

[Smithy 1,144]

OK, then I was wrong, thought that the print core remains on temperature.

So when all fans are off, the sound can only come from the steppers. I guess they are still powered to keep the position.

 

Because of your Z-screw I take everything back again, on the video it looked very dirty, but on the photo it looks good.

[NBull 14]

okay it seems that there is power on the steppers, the print head can't be moved when on pause.

 

So if the sound is from the steppers, (still hard to tell if the sound is from the stepper or not) is that "healthy" I don't know that much about how a stepper is different from a normal motor.

 

But to me it doesn't sound that good. again only with reference to normal electric motor.

 

I know it's probably a question for a developer. but why keep the stepper on power at all. why not just let the print head "home" befor starts up.

[Smithy 1,144]

The sound from a stepper sounds not healthy, but I haven't heard it yet on the S5. I can check it in the evening if my S5 makes a similar sound when I pause a print.

 

18 minutes ago, NBull said:

I know it's probably a question for a developer. but why keep the stepper on power at all. why not just let the print head "home" befor starts up.

 

I guess homing the head is not so accurate to get then back to the correct position. The home switches are only normal microswitches and they have some tolerances. So it is safer to keep the head in place to guarantee the next layer starts exactly where it should.

[NBull 14]

38 minutes ago, Smithy said:

The sound from a stepper sounds not healthy, but I haven't heard it yet on the S5. I can check it in the evening if my S5 makes a similar sound when I pause a print.

 

Thank you, that would be appreciated 🙂 please note that it takes some time before the print head fans shut off.

 

41 minutes ago, Smithy said:

I guess homing the head is not so accurate to get then back to the correct position. The home switches are only normal microswitches and they have some tolerances. So it is safer to keep the head in place to guarantee the next layer starts exactly where it should.

 

Agreed that would be a plausible explanation. But again pausing a print is in general not ideal for the print quality. 
And pausing a print is mostly don (at least in my case) because you have to leve the printer for some reason, when it can't be running.

And in this case I would rather risk a mismatch in the layer then a stepper burning out do to standing still. or at least that they had a timer so they would shut off after and hour or two.

[Smithy 1,144]

6 hours ago, NBull said:

Thank you, that would be appreciated 🙂 please note that it takes some time before the print head fans shut off.

 

So, I have tried now to start a print and paused it after some layers.

The head goes in a parking position in left front corner and the print core cools down. After some time the hotend fan in the middle of the head stops (this is when the temperature of the core is < 40°)

 

The noise I hear after that is in my opinion a mix between the two back fans and the stepper motors, but I have the feeling that the bass or the "body" of this noise (I hoper you understand what I mean, I have no idea how to explain it better in English) comes from the fans on the rear of the printer. I mean I can hear also the steppers but when then they are very silent compared to the two fans. 

 

Maybe the two fans also stop after some time, but I haven't tested it.

 

The sound itself, I would say it is unusual, but not alarming, so I have not the feeling it sounds unhealthy or something like that. It may sound like someone has the engine running from their car, but this car is relatively far away. Somehow it has something of a dull engine noise.

 

I hope it helps a little bit.

[NBull 14]

Thanks again for doing the test.

 

The two back fans, do you actually hear them as "fan/rotating blades" noise. or is that the engine humming sound also.  

 

After the head fan shouts off i have no fan noise. only the. engine sound, or more like sitting in an airplane with you fingers in the ears, background all around humming. 

 

I'm only asking to clarify, because I can't hear any difference from the stepper or back fans. (will not say my hearing is unusually) But the sound is all around and not specific to on part.

 

But it is comforting that you also have an "unusual" sound. Then it's not only me anyway, if thats good or bad time will tell 😉 

[Smithy 1,144]

It is more like the engine humming sound and thought that this sound cannot be the steppers. Then I checked the back fans and they were on full speed. After I aborted the print, the fans went back to normal speed and were not noticeable anymore. I could just feel the airflow.

 

I wouldn't worry about that anymore, the sound is unusual, but certainly nothing to worry about.