Retracting and Clicking  

RE: Retracting and Clicking

I just found the Prusa article about Extruder clicking and it said that when the motor is retracting like this, its because of a blocking or inability to push the filament through..

https://help.prusa3d.com/article/e6tym5n457-clicking-extruder-mini

Its printing lovely.. 2/3 of the benchy is done and its perfect.. So I don't think its a clog.. But I do need to do some tests to see if the filament path is clear.

So I think that the 'retraction' as I called it is NOT normal.. But the clicking is normal, but a side effect of another problem..

I am not entirly impressed by this.. Its a new printer and its not like its a kit that I built and therefore I could have made a mistake.. It came like this from the factory.. So what ever is wrong was like it when they made it and not when I built it...

RE: Retracting and Clicking

Mine does that too... if you gently grip the filament you can feel it doing it on retraction and deretraciton 

Currently does not seem to be effecting my print quality - but I am having other problems.

RE: Retracting and Clicking

My Benchy has just finished and its perfect.> no sign of any kind of blockage... If I grab the filament, I can't feel the "mini retractions", but when the big rewinds come (and the click) its obvious as the Filament moves back 10mm or so.

Everything seems normal.. And I am not worried about the "retractions" if thats what they are.. But the clicking makes it unusable in the place that it was destined to live.. I have seen loads of videos of it printing, and I don't recal ever hearing the constant clicking.

RE: Retracting and Clicking

Hi Jon,

have You tried to disassemble the extruder and see if ther eare any loose parts?
From the video I assume there is something loose, that doesn't sound like a electromechanic problem for me.

As for the retractions, I had a similar problem but my retractions were super fast and it didn't reretract.

Here is the Link if you are interested:

https://forum.prusa3d.com/forum/general-discussion-announcements-and-releases/sudden-fast-backspin-of-the-extruder-unable-to-print/

RE: Retracting and Clicking

Thanks Jan
I read about your problem and did think mine could be similar.. But I am not getting poor print quality..

I put a little visualizer on the motor and you can easily see the motor backspinning.

RE: Retracting and Clicking

Yep, had the clicking on my Mini.

Early on had had the 'hot end' issues, once they had been sorted (moving heatsink up etc etc), then the clicking was all down to the idoler in the bowden.

As suggested the head of tension idoler screw should be set flush with plastic housing (with no filament loaded), back it out half a turn when using TPU (Flex) or 'fill' (woodfill etc) filaments.

Had no issues or clicking since 😉 

S

RE: Retracting and Clicking

Posted by: @steve-4

Yep, had the clicking on my Mini.

Early on had had the 'hot end' issues, once they had been sorted (moving heatsink up etc etc), then the clicking was all down to the idoler in the bowden.

As suggested the head of tension idoler screw should be set flush with plastic housing (with no filament loaded), back it out half a turn when using TPU (Flex) or 'fill' (woodfill etc) filaments.

Had no issues or clicking since 😉 

S

I did look at the tension screw and its way back inside.. I started to wind it out until it got quite slopped, but the clicking remained.. As I was mid print, I decided to wait until it finishes to look at this again.. But based on what I saw, the tension did not help with the clicking.

RE: Retracting and Clicking

I'm just experiencing this for the first time. Ten hour print at .15 with gyroid infill. The infill is producing massive amounts of retracts and every layer is 90% ClickClunkClickClunk.

Five hours left and its driving me nuts. I need to find out the cause as soon as this print finishes.

RE: Retracting and Clicking

My problems have got worse this morning.. Came down to start to look at this and wanted to remove the filament.. The unload failed and the printer stopped trying to load or unload.

I removed the PTFE tube between the hotend and extruder and the filament was jammed solid.

I finally got it out and then pushed a bit through just check that there was no resistance and it seems OK, but its a bit tight around the olive which may or may not be right.

Whilst like this I tried to load filament just so spin the motor freely and it clicks as it goes round. Exactly like this to be honest:

https://forum.prusa3d.com/forum/hardware-firmware-and-software-help/y-axis-stepper-motor-clicking/

So I don't know whats going on now... I am not enjoying the experience at the moment, as compared to my MK3 which has given me ZERO trouble, this is becoming a pain in the arse already.

RE: Retracting and Clicking

I have found one thing.. I have taken out the PTFE tube in the hotend and measured it and its 43mm.. The instructions clearly state that it should be 43.4mm (+/- 0.1mm).. The spare you get in the bag is 43.5

So the on installed is 0.5mm shorter.. Could this matter?

RE: Retracting and Clicking

Posted by: @jweaver

I have found one thing.. I have taken out the PTFE tube in the hotend and measured it and its 43mm.. The instructions clearly state that it should be 43.4mm (+/- 0.1mm).. The spare you get in the bag is 43.5

So the on installed is 0.5mm shorter.. Could this matter?

 

Your original may have been 43.5 when originally fitted.

As part of the 'hot end' fixing process you loosen the top brass fixing 1/2 a turn, release the 3 grub screws and push up the hot end, then tighten the 3 grub screws. This process has pushed the hot end etc up against the PTFE tube.

Then you retighten the top fixing 1/2 a turn. This compresses the PTFE tube (to ensure not gaps that cause jams.

With a few heat cycles the PTFE tube may now be about 0.4 - 0.5 mm shorter 😉 

S

RE: Retracting and Clicking

So I removed the jam.. It was just filament stuck in the PTFE tube and easily fixed.

I checked the hotend and replaced the PTFE just in case.. I can easily push filament through with no resistance... But I put it back together and its still printing beautifully but clicking like there is no tomorrow.

I still can't work out whether the fast rewinds I am seeing are intentional retractions, or the motor backing off due to resistance.. And i don't like the sound the extruder is making when its free spinning (i.e loading and unloading), so I will have to get in touch with Prusa.

I have a colleague who got his Mini a few days before me so I can speak to him tomorrow and compare notes.

RE: Retracting and Clicking

Could someone do me a favour.. With no filament installed, could they do an "unload" (this will cause the extruder to go through its unload cycle without any load..

Do you hear any odd noises.. My has a background rattle which I think is the cogs engaging.. But also a regular "click"....

RE: Retracting and Clicking

Is the prusa mini filament drive similar to the MK3/s where two gears are meshed together to drive the filament between them and are one of these grub screwed to a drive shaft, because if so the regular click may be the grub screw not in enough and once per revolution of the gear, it hits the other gear as it comes round. If this is the case, you need to make sure the grub screw is aligned with the flat on the shaft and it should then screw in fully.

RE: Retracting and Clicking

I have today tried every setting on the tension screw, loose, tight and in between - it doesn't make any difference to my clicking.

RE: Retracting and Clicking

Posted by: @jweaver

Today I finally built my mini and immediately noticed something I don't like.

As soon as it started printing I noticed and odd clicking from the extruder.. it didn't sound like something slipping and clunking like when you have a jam... There was a kind of resonance to it.. Almost like something was 'bouncing'.. I don't know why but it sounds "intentional"..

The printer is printing its first benchy and its looking lovely.. But this clicking is getting on my nerves.. Its seems to happen during retraction.. Which brings me onto my 2nd point.

The Mini seems to do tiny little retractions (like the MK3) as it prints, but regularly does a larger, very fast reverse.. And its durign this change of direction that I get the click.

I am not sure why its doing these large retractions, but again, it just seems normal and I wonder if its to do with the bowden setup?

So I have 2 questions..

1. Is it normal for the Mini to do these minute and then larger retractions

2. Has anyone else got the clicking

 

I have recorded a video.. Sorry that its out of focus, but I wanted to capture the noise, rather the movemement of the extruder.

I look forwards to your thoughts

 

Jon

 

Hi Jon,

tldr; Disassemble extruder at make distance between gears a tiny bit bigger so reduce clicking noise.

I also had the clicking, I took apart the extruder and found the noise is due to the gears in the extruder assembly were to tightly forced together, I gave it a bit of slack and that helped on the noise, but I don't think it will ever go away completely. Perhaps if they shifted to helical gears instead of spur gears. But that would also be quite a bit more expensive if it is even possible to get them that small.

RE: Retracting and Clicking

Posted by: @superkirky

Posted by: @jweaver

Today I finally built my mini and immediately noticed something I don't like.

As soon as it started printing I noticed and odd clicking from the extruder.. it didn't sound like something slipping and clunking like when you have a jam... There was a kind of resonance to it.. Almost like something was 'bouncing'.. I don't know why but it sounds "intentional"..

The printer is printing its first benchy and its looking lovely.. But this clicking is getting on my nerves.. Its seems to happen during retraction.. Which brings me onto my 2nd point.

The Mini seems to do tiny little retractions (like the MK3) as it prints, but regularly does a larger, very fast reverse.. And its durign this change of direction that I get the click.

I am not sure why its doing these large retractions, but again, it just seems normal and I wonder if its to do with the bowden setup?

So I have 2 questions..

1. Is it normal for the Mini to do these minute and then larger retractions

2. Has anyone else got the clicking

 

I have recorded a video.. Sorry that its out of focus, but I wanted to capture the noise, rather the movemement of the extruder.

I look forwards to your thoughts

 

Jon

 

Hi Jon,

tldr; Disassemble extruder at make distance between gears a tiny bit bigger so reduce clicking noise.

I also had the clicking, I took apart the extruder and found the noise is due to the gears in the extruder assembly were to tightly forced together, I gave it a bit of slack and that helped on the noise, but I don't think it will ever go away completely. Perhaps if they shifted to helical gears instead of spur gears. But that would also be quite a bit more expensive if it is even possible to get them that small.

Cheers for that.. Whats still not clear to me is whether the back-spinning of the motor is normal.. Forget the clicking.. Should the printer be constantly retracting like mine does? My colleague got his mini a few days before me and his does NOT do this... So i am not sure I need to be solving the clicking, but the backspinning...

RE: Retracting and Clicking

I took the extruder apart today and there is no obvious source of the "clicking".. I am starting to think its more of a "rattle" than a click.

But I still can't get to the bottom of the 'retraction' that I see.. Even with the extruder appart and the motor running in thin air, I still get the large retractions (reverse rotations of the motor)

Everyone tells me this is not normal but I can't be 100% sure.. Could someone keep an eye on the big cog during the print, or hold onto the filament... I just need to be sure that the constant reversals/retractions that I am getting are not normal..

RE: Retracting and Clicking

Couple of videos showing the issue

Printer off - using finger to slightly move extruder cog creates clicking

and Printing