Retracting and Clicking  

RE: Retracting and Clicking

Just got a brand new prusa mini - and get the exact same clicking. Quality of the prints are excellent, but this clicking does not sound normal. The only thing I noticed was that the tensioner screw was set way tight from the factory - like all the way in - but unfortunately loosening it did not remote the clicking.

Did anyone ever find a proper fix for this? 

RE: Retracting and Clicking

Do a cold pull and post a photo.  

RE: Retracting and Clicking

The cold pull looks just perfect.  But remember that this is on a brand new printer, straight out of the box, on its very first layer ever.

• There is no clog. 
• The machine works flawlessly
• Perfect layers and perfect prints (even better than my trusty old MK3s)

It just clicks. And only on retractions.

No, it's not a clogged-kind-of-clicking like I'm used to on my MK3s when that jams. It's like in the OP's original video. A tinny, metallic click that kinda sounds like something is loose or backlash in the gears or motor or bearing or....

But again - the machine prints beautiful prints without any problems whatsoever!

RE: Retracting and Clicking

@loadinglevelone

Then, I try to isolate it.  If you can’t, don’t worry about it.   

RE: Retracting and Clicking

@loadinglevelone

The fix it to check and reduce the gear mesh between the two extruder gears.  The distance between the two gears is theoretically fixed, but tolerance stack up in assembly and parts can cause the gears to sit far enough that the gear mesh becomes too loose.  A loose gear mesh allows the gear on the motor to slap the extruder gear during fast restrictions causing an audible click sound.  Take apart the extruder and try to push the motor and the extruder gear closer together while tightening the screws down.  Just be careful not to over do it or the motor will have a hard time turning the gears with the gear mesh too tight. 

RE: Retracting and Clicking

@boom

I tried this. Did not solve the clicking. Gears were pretty tight against each other from the manufacturing. Tried forcing them together to the point of where the motor was struggling to turn, but the clicking was still there.

RE: Retracting and Clicking

@loadinglevelone

That's a bummer.  At least it's printing well.  Care to make a video of your clicking?   A while back I recall a post where the set screw securing the gear to the stepper came loose from the factory.  I don't think your filament feed is skipping because that kind of click is much louder and you will get shavings.  

RE: Retracting and Clicking

I guess I have the same problem as discussed before. So here's a video of the extruder clicking:

RE: Retracting and Clicking

Have You checked the locking screw in the motor shaft gear? if loose You get exactly this sound, since the motor shaft has a plain area where the screw pushes it keeps traction as needed (so print quality is ok) and You get a tick during direction change.

RE: Retracting and Clicking

@turro75

yep, I have checked it. (Unfortunately) that's not the problem :/

RE: Retracting and Clicking

try putting grease among gears and replacing the bearing.

RE: Retracting and Clicking

Posted by: @rupprupp

I guess I have the same problem as discussed before. So here's a video of the extruder clicking:

That is the 100% exact same sound that I have. No question about it. 
Tensioning or lubricating the gears does not help. Checked the grub screw and its ok. Small gear is firmly attached to the motor shaft. No play there.

the only thing I noticed when taking the extruder apart was that the inner diameter of the bearings was smaller than the gear shaft, thus there is some play in that. Replacing the gears would not do anything - I would have to find bearings with larger inner diameter or gears with larger shaft. 

RE: Retracting and Clicking

*stupid forum edit timeout*

... should be smaller inner bearing diameter. I will have take some calipers to the diameters and measure them. It most certainly is not a press fit as they are now. As a guess I would say at least 0.2mm difference between the gear shaft and bearing inner diameter, if not more.

RE: Retracting and Clicking

@turro75

Just put some grease on the gear --> does not help :/
but new bearings might be good idea

RE: Retracting and Clicking

@loadinglevelone

Interesting find on the bearing ID.  My shafts fit pretty well inside their bearing races.  Not to the point of friction fit, but an easy slip fit.  

The tolerance you found could be enough to be generating sounds, at this point I can't really think of anything else.  When I first received my printer last year , it clicked like all the videos in this thread and I was able to completely dial the sound out by reducing the gear mesh.  

RE: Retracting and Clicking

@boom:  Out of interest, do you notice any sound when you rotate the gear with your finger tip?

RE: Retracting and Clicking

@rupprupp

As of now, no.  I cannot even rock the gear right now because I have the mesh set to no lash.  When I first had the clicking issue, I could rock the gear back and forth and if I did it fast enough it would make a tapping sound.  

The two metal gears are machined pretty well, so there isn't much run-out in each of them.  Even with a closer mesh, the stepper doesn't work much harder to turn them, especially at normal extruding speeds.  If anything, the gear whine you hear when the motor spools to load/unload the filament is a little louder when running a tighter gear mesh, but not to the point that they are grinding or causing the motor the load up.

RE: Retracting and Clicking

Here's a video clip showing how it sounded when I first got the printer versus how it sounds now.

RE: Retracting and Clicking

RE: Retracting and Clicking

Do You have the filament sensor? have You checked the noise isn't actually coming from it?