"Nozzle Cleaning Failed." Error  

RISPONDI: "Nozzle Cleaning Failed." Error

This just happened for the first time for me using TPU. It took few tries. I lowered the temp a bit thinking perhaps the TPU was oozing a little too much. 

RE: "Nozzle Cleaning Failed." Error

Hi there,

I just started using the MK4 yesterday and I see the same issue.

I print in PC Blend. In my case, every other print was a "nozzle cleaning failure".

Thanks,

gabriel

RE: "Nozzle Cleaning Failed." Error

Does it seem even remotely 'true'? Any oozing? 

RE: "Nozzle Cleaning Failed." Error

Hey there Dean, yeah I see molten plastic sticking to the bed every time the nozzle taps into it.

The cleaning process forms two rows of dots on the heated bed before it gives up.

But I also see filament sticking out of the nozzle when cleaning succeeds so I am not sure what's going on.

With the MK3S+ I would just clean it myself with a pair of tweezers.

The fact that I have to take the steel sheet out, wait for it to cool off and then clean it is pretty annoying.

We must get to the bottom of this.

RE: "Nozzle Cleaning Failed." Error

Hi. bringing 2cts. I observed cleaning nozzle failures with an old PLA spool that has a very low melting temperature. Since I noticed the nozzle cleaning would set 170℃ for a PLA with a 215℃ , I manually lowered the temp to 150℃ during that phase for my PLA. this solved the problem. Not sure where this procedure is described in extra gcode from prusa slicer or in the firmware direclty, but it seems it should derive the nozzle cleaning temp from the first layer temp, or something more clever than a fixed value.

Cheers!

RISPONDI: "Nozzle Cleaning Failed." Error

I'm also getting this problem and the nozzle never seems to be blocked usually after a a print is done and i reprint... Is this a bug?

RE: "Nozzle Cleaning Failed." Error

I'm getting this especially with PCCF, it oozes particularly bad at 260c. I'm going to try reducing the temps until it stops oozing.

RE: "Nozzle Cleaning Failed." Error

I've found that making sure that the previously deposited filament is cleaned off in the front nozzle cleaning test area helps avoid this. Restarting fixes it, as well, it seems.

RE: "Nozzle Cleaning Failed." Error

I had good success with setting the the extruder temp to -50 from -25 for bed leveling in the Custom G-Code section for the Start G-Code.

M104 S{first_layer_temperature[initial_tool]-50} ; set extruder temp for bed leveling

M109 R{first_layer_temperature[initial_tool]-50} ; wait for temp

RE: "Nozzle Cleaning Failed." Error

Tony, will using -50 show 145⁰ as the temp for nozzle cleaning and bed probe?

I tried this, and it's still showing 170⁰.

I haven't been able to print anything since going to firmware 4.7.  going back to Alpha LC.

Chris.

Prusa Chat Support isn't responsive.... I got on this morning with a 6 minute wait, 10 minutes later a still had a 5 minute wait.  At that rate I have a 1 hour wait, not 6 minutes.  Glad I overpaid for the great support.

RE:

I did a full factory reset with firmware and it's still failing.  Using the Prusament that came with the MK4.

I took the nozzle out yesterday and everything seems fine with it... Prints still failing.

Chris

RE: "Nozzle Cleaning Failed." Error

I have the same problem. But fortunately it only shows me this error occasionally. I just take isoprophyl alcohol and clean the bed properly and take the nozzles with a brush. And then the next print goes through just fine for me.

RE: "Nozzle Cleaning Failed." Error

I had the same issue. I was printing with an older roll of generic PLA and printing the buggy parts that came on the thumb drive. It did it twice. I cleaned the dots off the sheet each time. After the first nozzle clean failure, I set the nozzle temp to 275 and waited a few, then cleaned the nozzle with the felt nozzle brush I use for the mini. That didn't work so I went to the knowledge base and figured out that if it fails I should recalibrate the load sensor in the extruder. The way I found to do that is do the self test. Did that and I haven't seen it since. That being said, I have only printed 2-3 times since.

RE: "Nozzle Cleaning Failed." Error

Problem solved 😄

Need change part: heatsink with loadcell

After change this part loadcell value fix and print agian perfect. Prusa service send me new part and now everyting perfect.

RE: "Nozzle Cleaning Failed." Error

I have the same error.
Checked the different threads and tried what was advised (reduce the temperature during that phase for exemple).
Chatted a few times with the support

We tried the firmwares :

• 4.7.0 (can't make the printer work)
• 4.7.1 (can't make the printer work)
• 4.7.2 (can't make the printer work)
• 5.0.0 RC (can't make the printer work)
• 5.0.0-alpha4 (get the nozzle cleaning failed but when retrying it sometimes work)

We checked the belt tension, re-did the self-test. Factory reset.
We changed the loadcell.
We tried on a smooth sheet and a satin sheet.

I did 2 cold pull to be sure the nozzle was clean (it went ok and as expected the nozzle was really clean).
I use Prusament PLA (some is old but got dried, all the other were brand new).

Nothing works.
I had a few spare time so I dismantled and rebuild the printer last week-end (X and Y axis). I have the exact same error.
self-test passes ok but I just can't print (5.0.0 RC).
Nozzle cleaning failed.
bed cleaning with 99.9% IPA.

I can't read the gcode but can someone enlight me about what does the printer do exactly during the nozzle cleaning phase and what feedback it expects (basically the inputs and the outputs)?

Support told me my case will be reviewed by one of their specialist but I'm yet to get some news from them.

At this point if someone has any idea, i'm taking everything as I've been struggling with that error for a month already.

RE: "Nozzle Cleaning Failed." Error

I had the same issue printing PCCF with the stock settings. There seems to be a significant amount of oozing. I went back to PLA, and it worked fine. Changed to PCCF again and the same problem occurred again.

After reading your comments, I lowered the temp to 240 during the nozzle cleaning and calibration, and it seems to solve the issue. I could not find a separate setting in the slicer for the cleaning temp, so it really must be some kind of calculation based on the normal printing temperature. 😐

With this solution it still collects a small ball of filament on the nozzle until the calibration finishes, which I removed with tweezers...

RE: "Nozzle Cleaning Failed." Error

I ran into this with PLA+CF. Lowering the nozzle temperature from 170 to 150 seemed to fix the problem.

We need some way to control nozzle temps when cleaning.

RE:

I have had the same issue and after a lot of back and forth with prusa support we found out, that the sledge carrying the heatbed hits the caps on top of the z-axis, so the heatbed can never touch the nozzle. 

After unscrewing one of the z-axis caps I can now use most of the printer and they will get back to me next week. 

I suppose the solution in my case is to print new, slightly altered z-axis caps.

I'm still baffled as to how this could be happening.

RE: "Nozzle Cleaning Failed." Error

I'm being hit with this too. So far the only fix I've found is to unload and load the filament, then everything works.

Can some kind soul explain what this step is meant to do and why it does it at 170c. Naively I'd expect it to wipe it's nose at a temperature that would melt the filament.