Retracting and Clicking  

RE: Retracting and Clicking

Posted by: @turro75

...but if it worked well at the beginning...

My printer have always had this clicking. Even from the very first layer calibration print. Thus, this is not a slack that has evolved over time due to wear.

RE: Retracting and Clicking

Posted by: @loadinglevelone

Here I move the wheel by hand between the two endstops of the slack. No filament loaded.
Sound is a little faint, but if you turn the volume up you can hear the same clicking.

That's definitely enough slack to cause clicking.  The spur shouldn't move at all when moving by finger.  

There isn't any adjustment built into the extruder to actually adjust gear mesh, but the two holes in the PETG for the two screws that secure the stepper motor are large enough that you can loosen the screws and get the motor closer to the gear.  It's a bit of a trial and error process, but play with it a couple times and you'll know what "feels" and "sounds" right.  You don't even need to mount the extruder back onto the X axis mount while you're doing this, just let it hang off on the side so you can have quick access to the screws to take apart the extruder.

However, I recall you also have a shaft that sits loose in a bearing.  That is still a variable and probably hard to eliminate unless you replaced the bearing or the gear in question.

RE: Retracting and Clicking

Posted by: @turro75

I took out from the drawer my old mini extruder to inspect it, in the end we are talking about 2 bearings and 2 gears.

Have You checked the motor shaft gear is in the right place? I attached a picture taken from the clone manual so that quote may be wrong. if You can, check Your current position and ask to prusa support if it is correct or no. May the big gear hitting the locking screw. 

May be one day when the official assembly manual will be released we all know how stuff must be assembled. 

 Schermata-da-2021-02-15-18-21-35.png

The official assembly manual has been out since the release of the Mini+ kit.  There is even a full step by step version on this Prusa website.

RE: Retracting and Clicking

@loadinglevelone

Is it only one bearing that has a larger ID?  Or is it the shaft on the gear that is undersized?  

All three bearings in the extruder (The two the extruder spur gear rides on, and the idler tensioner bearing) are the same size.  If you want to eliminate the bearing, you can rob the tensioner bearing and see if that bearing has a better inner diameter tolerance.  Put the one with the slightly messed up ID on the tensioner, since that bearing doesn't do anything besides put pressure on the filament.

RE: Retracting and Clicking

@boom

thanks I wasn't check the prusa site for weeks

RE: Retracting and Clicking

I decided to order new bearings, gears and 3D-printed parts for the extruder. I will let you know if anything changes with the new parts.

Thank you very much for your help so far!

RE: Retracting and Clicking

Posted by: @rupprupp

I decided to order new bearings, gears and 3D-printed parts for the extruder. I will let you know if anything changes with the new parts.

Thank you very much for your help so far!

I went back and watched your video

It looks like there is still a bit of play in the gear.  That is,  you can still rock it back and forth.  Have you tried to adjust it again so it does not rock at all?  I don't think new parts are going to help unless you take out all the rocking.  Loosen the two screws that secure the motor to the plastic housing, and push it towards the gear.  It might take a couple tries to get it perfect, but that's all I did to get rid of the click.  No software changes, no part replacements.

RE: Retracting and Clicking

@boom

Yep, in this video I loosened the gears again a bit. I also tried many times to force the gears closer together, however then I quickly get a grinding noise like this:

Even though I tried many times to find a good configuration, I was never able to get rid of both grinding and clicking noise.

RE: Retracting and Clicking

@rupprupp

Aw man, that's too bad.  

It sounds like you've tried many combinations already, but just to throw it out there, one thing I noticed was that moving the motor position was very sensitive and a pain because you have to take apart the two extruder halves to access the two screws.  Instead, get the motor close but don't force it up against the gear, then fine tune the position the two halves come together to get a good mesh.  https://help.prusa3d.com/en/guide/3-x-axis-extruder-assembly_199519#201185   Reference Step 42.  Before tightening those three screws, slide the part marked F1 slightly downward to get the two gears to mesh with no slack.

But, if you're saying you are getting clicking AND grinding at the same time, then there is probably something else we've overlooked.

RE: Retracting and Clicking

Posted by: @boom

@rupprupp

Aw man, that's too bad.  

It sounds like you've tried many combinations already, but just to throw it out there, one thing I noticed was that moving the motor position was very sensitive and a pain because you have to take apart the two extruder halves to access the two screws.  Instead, get the motor close but don't force it up against the gear, then fine tune the position the two halves come together to get a good mesh.  https://help.prusa3d.com/en/guide/3-x-axis-extruder-assembly_199519#201185   Reference Step 42.  Before tightening those three screws, slide the part marked F1 slightly downward to get the two gears to mesh with no slack.

But, if you're saying you are getting clicking AND grinding at the same time, then there is probably something else we've overlooked.

That's a good one. Indeed, it's very sensitive, so that might be a good approach. I'll give it a try!

Actually, it was so far a continuous transition between grinding and clicking. If the gears are loose, the clicking strongly dominates. The closer the gears, the louder the grinding and quieter the clicking.

RE: Retracting and Clicking

I changed both gears with new ones in my Mini and the click is still there. There is still a bit of play in the gear, nothing changed.

RE: Retracting and Clicking

Just a question for everyone with the clicking what brand of filament are you using and type?

Im trying to decide if less issues are seen with Prusament, I tend to use Hatchbox but it still screws up with that also 😩 

Im thinking of getting some Prusament PLA just to see if the problems are less.

RE: Retracting and Clicking

@raymate

Brand doesn't matter. It's the same for all brands. Must have used the mini with about 15 brands by now, prusament included and it's just as bad.
Same with both PLA and PETG.

RE: Retracting and Clicking

Most of the clicking I have is with generic filaments.  

RE: Retracting and Clicking

I just built and finished a brand new Prusa Mini +.  Put me in the camp that has the clicking retraction noise.  My prints are PERFECT but the clicking is annoying.  Watching this thread in the hopes of a resolution.

I suspect the resolution will be Prusa offering up new Extruder STL's and instructions.  Anybody know if they are aware of this?

RE: Retracting and Clicking

I'm tearing into this a little bit.  I tried removing the extruder and positioning the motor tighter to the pulley gear as someone suggested.  Did not clear up the click.   Everyone mentions the retract as the source of the noise, and maybe it is, but there is a Z lift going on as well.   The retract is about 3.2mm on my slicer with a speed of 70 and a lift of 0.2.

With 2 retract, 50 retract speed and no z lift it is a tiny click but not as pronounced but still there. 

With my print quality as good as it is I'm going to live with the click.  At some point Prusa will address this with some revision I'd be willing to bet.

RE: Retracting and Clicking

Sorry to post > post > post.  Did a chat with support about this issue this morning.   Not to complain about it but just to see if they were aware.  I sent a video in of my retract click and the two techs I was talking with said that was a normal noise.

I know some of you have had different experiences with support (don't shoot the messenger 😀 , just relating what I was told).

They did tell me to check the motor gear for tightness and to put one dollop of the bearing grease on the gears.

I inspected my extruder and while my hobbed gear was tight, I uber tightened it, and put the grease on.  I still get the click however it is greatly reduced and the backlash (retract to filament sensor) seems kind of greatly reduced.

But it does still click.  I get perfect prints, no extrusion issues.  I'm calling it "good, but slightly annoying".  I've had Prusa's since 2016 and one thing I know is for sure that they'll make revisions on their parts eventually, especially on current production stuff. 

Your mileage may vary but I think the retract click is okay.

All that being said, I ran a compact Bowden for years on a RepRap (and I still use it) and it has never clicked once.

That's where I'm at.  But if they ever change it and fix the click I'll be one of the first guys printing off the rev stuff. 

RE: Retracting and Clicking

Does anyone know if the Bondtech extruder upgrade has the same annoying sound ? Just got my Mini 2 weeks ago, and have been printing like crazy, no problems with the print quality, but the clicking is annoying when having the printer in the same room.

RE: Retracting and Clicking

I was having this problem too.

The print even stopped building, there was no extruding.

I heated the hot end up to max, pushed some different filament thru, changes the print to a different filalament.

NO PROBLEMS - I changed nothing else. Either the nozzle was plugged or the filament is the problem.

Maybe moisture ( I dont store mine in dry boxes - until now )

RE: Retracting and Clicking

@justme

It could be either the filament or a plugged nozzle.  Congrats on the fix.  I would keep a tungsten rod around to push past those clogs.