Prusa mini extruder noise  

RE: Prusa mini extruder noise

I've just received and assembled mine, and I'm having the same issue. It seems to be working fine, and the extruder makes no noise when it's just extruding. It's when it changes directions for retracts it sounds like the gears are rubbing or resonating something. I've taken the extruder apart to double check my assembly and everything seems correct. Playing with the idler tension doesn't change the noise at all either. 

Kind of stumped, maybe it'll work itself out?

RE: Prusa mini extruder noise

have observed same with pre-assembled Mini+ from Nov 2020.  Doesn’t seem to be affecting print quality.  

RE: Prusa mini extruder noise

Maybe  the printer  is just noisy. After a lot of tinkering I cannot get the printer any quieter. I also had quite a lot of problems with it, even though afterwards I was pleased again withh the print quality. The gears noisse has reduced over time. However now I hear the motors. I will just place an  enclossure over it and be done with the noise problem.

RE: Prusa mini extruder noise

The clicking for me is definitely coming from the extruder when the filament is retracted during a print.  Sounds like gear backlash.

RE: Prusa mini extruder noise

I am having the same with my brand new mini +. Retractions sound really strange

RE: Prusa mini extruder noise

@jayke

I would try to reduce the retract value and the speed (retract 2mm, feed 30mm/s).

Possibly deactivate retract...

RE: Prusa mini extruder noise

I am not yet slicing my own models for this printer, I am so far just testing it with the models provided on the USB stick. So I would imagine that's not the problem.

I've made a recording of the sound, perhaps someone can identify if this is normal and if not what can be done about it:

RE: Prusa mini extruder noise

@jayke

Yes that is the same noise I hear - has been there since new ~ 5 months...

RE: Prusa mini extruder noise

@jayke

It sounds like the gears are rubbing against the plastic housing. It is also possible that a bearing is loose. I would disassemble the extruder and check this.

https://help.prusa3d.com/en/guide/how-to-access-and-clean-the-extruder-pulley-mini_126457#126727

RE: Prusa mini extruder noise

@karl-herbert

Karl, I tested your suggestion, the clicking is still present.  There is some slack between the extruder gears and when it switches from extruding to retracting and vice versa, the gears make a click.  Occurs more often on a small object (ie: the tree frog) For me it has never caused any print issues... just a minor nuisance when in the same room.

RE: Prusa mini extruder noise

@karl-herbert

I have taken the extruder assembly apart, the gear spins freely in the bearings with no noise at all. I've also checked that there is no rubbing against any plastic, and it seems to be okay.

Then I took the stepper out and ran it without anything attached. It appears that there is something weird going on there. The stepper actually makes a clicking sound when rotating (in both directions), see the video below. I think the reason it's noticeable during retractions is because it spins faster than during extraction. And in fact, when loading the filament when it fills the ptfe tube towards the hotend, it also makes a lot of noise.

Is it time to contact support about a potentially faulty stepper motor?

RE: Prusa mini extruder noise

Contact Prusa Chat, and give them the URL for this video... 

they should be able to help you!

regards Joan

RE: Prusa mini extruder noise

Check the bolt that supplies tension for the extruder. It will be on the right side, as viewed from the front of the printer. If it is loose, it can be pretty noisy because the filament is slipping. It can also lead to under extrusion.

I had to tighten mine down yesterday, the trick is not too tight. I would check that first.

RE: Prusa mini extruder noise

@jayke

That’s interesting and seems to be different than what I experienced. But, out of curiosity, did you check the tensioner for the extruder?

RE: Prusa mini extruder noise

Had to disassemble the extruder today, a lot of build up of filament shavings inside.  I also found the source of the clicking noise on retraction - as suspected it is the slack between the gears - have a listen to the attached video:

extruder-clicking3

RE: Prusa mini extruder noise

Very interesting - thanks for the feedback!

I would contact Prusa through the chat. You may receive a replacement.

Just login with your Prusa account and select the eshop. After a few seconds the chat window should appear on the lower right corner. If the chat window does not open, disable a possibly activated adblocker or try another browser.

RE: Prusa mini extruder noise

Im new to 3D printing and I’ve run into some problems. When I first got the printer everything was printing fine up until four weeks after when it stopped printing halfway through a print. When I unloaded it the filament had grooves in it from where the extruder chipped away at it. After seeing that I clean the extruder I raised the heat break and also replaced the nozzle and nothing works it can’t even get a first layer down without it getting chewed up. The weird thing is I can load and unload it and also purge and everything seems fine it only happens when I print.

RE: Prusa mini extruder noise

@karl-herbert

Thanks Karl, I chatted with support and they recommended I check the set screw on the extruder.  While it was good and tight it was installed wrong at the factory (this was a pre-assembled Mini+).  You can see in the picture the grub screw is not screwed into the flat part of the extruder shaft.  That would have likely loosened up faster.  After reassembling the clicking is still there.  I think I will print a new housing and perhaps new gears and bearings.

.

RE: Prusa mini extruder noise

@daryl-2

Mine also have these clicking noise. It seems the gears has some "play" between the teeth. I believe there is no quick fix for this.

I will try some other Gears here if i find the same dimensions (or print myself some in nylon)