Prusa mini extruder noise  

RE: Prusa mini extruder noise

OK  so I finally tried to move the extruder big gear up aboout 0.1 mm. At the start was a huge succes no more noise while loading the filament but then  the gear backlash came to say hi. Well it was a nice trry. I thought I`ll post the results any way so that no one has to try. I might try moving it down and see what happens.

Before:

loading: https://photos.app.goo.gl/RT16zUmWaKgCayx48  

backlash: https://photos.app.goo.gl/HJGHKxnHjLs8pqF38

After:

loading: https://photos.app.goo.gl/AJ4xuUPWo664QB7W7

backlash: https://photos.app.goo.gl/zCvQDx3spEp9i8hn9

RE: Prusa mini extruder noise

I tried to move it down 0.12 mm. The sound is there, I am pretty sure the backlash is gone so that cannot be the issue. I want this printer to be nearly silent but with that retraction noise... imposible.

video with the gear moved 0.12mm: https://photos.app.goo.gl/PvZGUADhf21YZXVX9

RE: Prusa mini extruder noise

@luison44

Hi there, did either of these fixes work or is there any further development? 🙂

Just before I start hassling the Prusa Chat! Thread has been very insightful, thanks for sharing 🙂

RE: Prusa mini extruder noise

@polyphant

I am afraid not. After a lot of thinking I cannot find a way to stop that noise. I tried lube, moving the gears, oil, placing my finger on top,... Nothing stops that sound.😭😭 I ended up moving the printer to the furthest room. Happy to help friend.

RE: Prusa mini extruder noise

@polyphant

Try this:

Saw this somewhere: I opened the extruder, loosened the servo screws and re-tightened it after pushing the motor towards the pinion: before it was a click-click noise, now it is a gentle humm.

RE: Prusa mini extruder noise

Posted by: @luison44

@polyphant

 I ended up moving the printer to the furthest room. 

That is a simple solution if you have enough room.  My wife is banishing my printers to our new workshop.  

RE: Prusa mini extruder noise

Is there an actual fix for this, and or, has there been any official word from Prusa re. this issue?   I have this issue with a brand new, out of the box one.  

RE: Prusa mini extruder noise

I got my assembled Mini+ a couple of weeks ago, and it also makes this noise. I assumed it was normal until I found this thread. I removed the filament sensor as suggested by another post, but the noise remains. 

RE: Prusa mini extruder noise

I think it's safe to say that this comes from the design of the extruder itself.

There are 2 possibilities, the big gear with " backlash ", the big gear without backlash.

With backlash the gears make a characteristic noise when retracting, a rather annoying click-click sound when retracting repeatedly, loading/unloading filament is done without too much noise. On the other hand, if the motor gear is forced too far towards the large gear, the backlash is completely eliminated, but the teeth are too close together and a grinding noise is heard.

I disassembled the extruder dozens of times to find the right compromise, but I could not eliminate the click-click sound when retracting.

I think this problem is not solvable without changing the design of the extruder and maybe switching to the mini bmg with all that it entails (reversing the motor cable, managing the esteps at each restart).

I am very happy with the mini EXCEPT for this noisy extruder, I am not a mechanical specialist for a large plastic gear would surely have been less noisy than a metal one (like on the titan and bmg)

RE: Prusa mini extruder noise

@galvanization

It is probably normal.  Hard top judge without hearing it.  

RE: Prusa mini extruder noise

Here are a couple of videos demonstrating the noise(s). One is normal printing where you can here the "grunting" of the extruder here and there. The other is the filament unload. The noises don't actually bother me as the printer is in another room, I just want to make sure they are normal and not subjecting it to extra wear. 

The microphone makes it sound a lot louder than it is, I guess the fan noise could be used to judge the relative volume level. 

Filament Unload:

Printing:

RE: Prusa mini extruder noise

Posted by: @federico-2

@polyphant

Try this:

Saw this somewhere: I opened the extruder, loosened the servo screws and re-tightened it after pushing the motor towards the pinion: before it was a click-click noise, now it is a gentle humm.

 

This suggestion seems to have resolved the problem.  The cog from the motor to the extruder were not meshed together correctly when turning, hence the noise. By pushing the motor "up", closer to the extruder cog, seems to have fixed it. 

As mine was originally put together by Prusa, maybe there's some quality assurance needed during assembly so new customers don't have this issue in the future, and worried their printer is faulty? 

Other than that, this mini+ is a great little printer! Thanks Prusa.

RE: Prusa mini extruder noise

Good news.  That was a very loud noise on the last unload video.  

RE: Prusa mini extruder noise

Following up - just took apart my extruder and also noticed that the set screw on the motor gear was not facing the flat part of the shaft! Realigned that and now the filament loading is much quieter, as is the "grunting" noise on retraction. 

RE:

I had the same noise during retraction and filament insertion and swap. I've disassembled the extruder and saw a lot of black powder everywhere. Cleaned it and reassembled everything. The clicking/grinding noise is gone. It's now a very quiet machine. 

My theory is that it is the extruder design, it has to be more robust. I've seen a lot of solutions for this issue and they are all different. 

Disassemble, clean, check the screw position on the motor shaft, retighten everything and some say that the filament tension screw is also needed to be adjusted... and finally, pray.

RE: Prusa mini extruder noise

Do you think the black powder is ground up filament?

RE: Prusa mini extruder noise

mmm... I think not. I use only white, orange, and blue since I bought the printer. Unfortunately, I forgot to test the powder with a magnet...silly me. 

RE:

I had a lot of black powder. Got a magnet near it and all the loose particles stuck to the magnet. It isn’t ground up filament but ground up metal (whatever the gears are made of). I don’t know what to do

RE: Prusa mini extruder noise

Black magnetic powder: This can actually only result from the extruder. I would disassemble it and check the gear drives and bearings. You can find a description here:

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

https://help.prusa3d.com/en/article/regular-maintenance-mini_133222

If the problem persists, i would contact the prusachat (Just log in with your Prusa account and select the eshop).

wbr,

Karl