RE: Nozzle cleaning consistently fails with PETG
This is exactly what I am talking about and have an open github issue. And retracting the filament is one of the fixes. The term "nozzle cleaning" is inappropriate, hence the confusion. But the issue is exactly that step that can fail.
RE: Nozzle cleaning consistently fails with PETG
I've printed primarily with PLA, PETG, and TPU. Only ever get the 'nozzle cleaning failed' error with TPU, and it's quite regular.
Annoying but just a bug im sure will be resolved.
RE: Nozzle cleaning consistently fails with PETG
I have the same nozzle cleaning issue that I couldn't get past with PETG after the first couple of PETG prints. Almost 100% of the time it couldn't get past the nozzle cleaning stage. I'm using the prusa satin sheet for PETG. I have the logo and text right under the cleaning area. I did as @rob-hills suggested and moved the print sheet towards the door by about 2 cm. After it releveled, nozzle cleaning worked and the print started. I'll try again after my current print finishes to make sure it wasn't a fluke but I spent 20 minutes this morning trying to get it to print until I tried moving the print sheet forward.
I found the same issue before coming here to see if others were having problems. I noted that the nozzle cleaning function occurs over the prusa logo. You can feel the height variation there with your finger. Moving the sheet down a little so that it cleans in a consistently flat portion of the satin sheet fixed my problem.
I have Core1 sheets and they don't have a logo at the cleaning positon. The logo is in the middle of the sheet.
RE: Nozzle cleaning consistently fails with PETG
I don't yet have my core-one conversion kit, so this may not help, but on my Mk4(s) I also only had trouble with TPU while nozzle cleaning. The fix was to drop the probing temp of the nozzle by 10 degrees in the slicer gcode. I haven't had any failures since.
The core one may be a bit more sensitive than the Mk4(s), but it's worth trying if TPU is the only filament still giving you problems.
-J
I've printed primarily with PLA, PETG, and TPU. Only ever get the 'nozzle cleaning failed' error with TPU, and it's quite regular.
Annoying but just a bug im sure will be resolved.
RE: Nozzle cleaning consistently fails with PETG
I don't yet have my core-one conversion kit, so this may not help, but on my Mk4(s) I also only had trouble with TPU while nozzle cleaning. The fix was to drop the probing temp of the nozzle by 10 degrees in the slicer gcode. I haven't had any failures since.
The core one may be a bit more sensitive than the Mk4(s), but it's worth trying if TPU is the only filament still giving you problems.
-J
I've printed primarily with PLA, PETG, and TPU. Only ever get the 'nozzle cleaning failed' error with TPU, and it's quite regular.
Annoying but just a bug im sure will be resolved.
I tried this on my Core One but the 10 degree C difference didn't fix it. The nozzle cleaning still failed. So far the only thing that's worked is @rob-hills suggestion to pull the print sheet forward a bit so the cleaning happens on the non-logoed area. I'm now on my 3rd PETG print in a row and no nozzle cleaning failures since.
RE: Nozzle cleaning consistently fails with PETG
Update to my post. I switched out the black PETG that started printing after I pulled the print sheet slightly forward so it wasn't cleaning on the prusa logo with orange PETG that had been working on the core one. With it, no matter what I did the nozzle cleaning would always fail even moving the print bed.
I also have a Kobra 2 Max bed slinger. So far I'd only printed PLA on it given my past failures with PETG on other printer. I thought what the hell. I removed the organ PLA from my core one, loaded into the Kobra and on the first try to the simple nozzle cleaning it does of a long line along the top, it's been printing PERFECTLY.
After spending $1200 US on the core one and another $200 for fed ex custom charges and waiting 8 weeks for it to arrive, I'm really beginning to doubt my choice.
Don't get me wrong, once I can get the damn machine to actually PRINT, the prints are amazing but when I have to fight with it for 20 minutes or more for nozzle cleaning, failure to clean, a long cycle before it even starts printing or not even getting past that to print and yet my Kobra 2 Max at 1/4 the price has NEVER failed to start printing nor failed a print yet in both PLA and PETG...
I don't yet have my core-one conversion kit, so this may not help, but on my Mk4(s) I also only had trouble with TPU while nozzle cleaning. The fix was to drop the probing temp of the nozzle by 10 degrees in the slicer gcode. I haven't had any failures since.
The core one may be a bit more sensitive than the Mk4(s), but it's worth trying if TPU is the only filament still giving you problems.
-J
I've printed primarily with PLA, PETG, and TPU. Only ever get the 'nozzle cleaning failed' error with TPU, and it's quite regular.
Annoying but just a bug im sure will be resolved.
I tried this on my Core One but the 10 degree C difference didn't fix it. The nozzle cleaning still failed. So far the only thing that's worked is @rob-hills suggestion to pull the print sheet forward a bit so the cleaning happens on the non-logoed area. I'm now on my 3rd PETG print in a row and no nozzle cleaning failures since.
RE: Nozzle cleaning consistently fails with PETG
I also had the nozzle cleaning failing with TPU. Then i noticed that the temp at that stage is slightly over the printing temp. well of course TPU will keep oozing out. So i manually lowered the temp and retried. then raised it before print. It then succcedded through the cleaning step. Mind you i was also cleaning it with a bronze brush, and that still didn't help when the temp was high.
RE: Nozzle cleaning consistently fails with PETG
More just to add to the numbers yet to talk to support but nozzle cleaning always fails with PETG on my old textured plate and using the logo area
My XL and MK4s dont have these issues well the MK4s sometimes but thats definitely because the nozzle "cleaning" routine sucks big time
In contrast to my A1 mini it's embrrceing that thing dose a very good clean and scrub even with damp filmets before a print.
RE:
I think they should specifically make the firmware lower the temp just a few degrees when at the nozzle cleaning and then probe section. to stop petg and flex from oozing. i get that its done so that filament will stick to the plate, but when its too high it just keeps on oozing out.
Is there an open ticket in github for a solution to this?
RE: Nozzle cleaning consistently fails with PETG
I cannot comprehend why Prusa isnt embracing a better approach for nozzle cleaning. This seems to stem from a place of pride and stubbornness rather than actual common sense. The current nozzle cleaning process along with the multiple bed probing failures interrupts immensely with my workload and has robbed me from hours of productivity that I could have spent designing the parts that actually make me money.
Sitting in from of the prusa and baby sitting it, does not make money, in fact, it makes me loose money. The equation is then very simple, at this price point I expect to press print and forget AFTER I set up the printer correctly. I do not have time to wait for chambers to heat up, to nozzles to get clean and bed levelling to fail especially at the price proint these are at.
I am still within the 60 day return period. Prusa is giving me the run around and support has told me 'We will get back to you, as your case is being reviewed". I am VERY close to return this machine, which will have an added cost of both time and money, further interrupting my business. I was expecting more from Prusa and this being my first one, I have to say that I am not impressed and this machine is not ready to be sold. In this current state I would consider it BETA at best.
RE: Nozzle cleaning consistently fails with PETG
I also had the nozzle cleaning failing with TPU. Then i noticed that the temp at that stage is slightly over the printing temp. well of course TPU will keep oozing out. So i manually lowered the temp and retried. then raised it before print. It then succcedded through the cleaning step. Mind you i was also cleaning it with a bronze brush, and that still didn't help when the temp was high.
Yep, I print my TPU at 210, hardly any oozing whatsoever.
RE: Nozzle cleaning consistently fails with PETG
After one successful print I can longer get past the nozzle cleaning stage. Fails every time. Brand new core assembled, petg on a textured sheet. The nozzle is visibly pristine. I tried raising the temp, wire brush and even canceling and retrying. Nothing works.
RE: Nozzle cleaning consistently fails with PETG
I’ve had the same issue, it seems better now though I can’t tell you what I did to change it. I started heating the nozzle to around 200c and cleaning the nozzle, cooling it down to 170 and wiping the bed with isopropyl alcohol in particular where the nozzle cleaning occurs and then start the print.
It seems more reliable now but I still have cleaning failures.
RE: Nozzle cleaning consistently fails with PETG
For what it's worth, since I flashed my Core One firmware to 6.3.3, out of 5 PETG prints since the flash I've had NO further nozzle cleaning issues.
All started with no intervention from me and have printed flawlessly. Other than pulling off the hanging couple cm of filament after a print finishes, I've had no issues starting the prints and this is with PETG filament that has been in the open air, no drying, with humidity between 45 and 60% in the house for the last 6 weeks.
Update to my post. I switched out the black PETG that started printing after I pulled the print sheet slightly forward so it wasn't cleaning on the prusa logo with orange PETG that had been working on the core one. With it, no matter what I did the nozzle cleaning would always fail even moving the print bed.
I also have a Kobra 2 Max bed slinger. So far I'd only printed PLA on it given my past failures with PETG on other printer. I thought what the hell. I removed the organ PLA from my core one, loaded into the Kobra and on the first try to the simple nozzle cleaning it does of a long line along the top, it's been printing PERFECTLY.
After spending $1200 US on the core one and another $200 for fed ex custom charges and waiting 8 weeks for it to arrive, I'm really beginning to doubt my choice.
Don't get me wrong, once I can get the damn machine to actually PRINT, the prints are amazing but when I have to fight with it for 20 minutes or more for nozzle cleaning, failure to clean, a long cycle before it even starts printing or not even getting past that to print and yet my Kobra 2 Max at 1/4 the price has NEVER failed to start printing nor failed a print yet in both PLA and PETG...
I don't yet have my core-one conversion kit, so this may not help, but on my Mk4(s) I also only had trouble with TPU while nozzle cleaning. The fix was to drop the probing temp of the nozzle by 10 degrees in the slicer gcode. I haven't had any failures since.
The core one may be a bit more sensitive than the Mk4(s), but it's worth trying if TPU is the only filament still giving you problems.
-J
I've printed primarily with PLA, PETG, and TPU. Only ever get the 'nozzle cleaning failed' error with TPU, and it's quite regular.
Annoying but just a bug im sure will be resolved.
I tried this on my Core One but the 10 degree C difference didn't fix it. The nozzle cleaning still failed. So far the only thing that's worked is @rob-hills suggestion to pull the print sheet forward a bit so the cleaning happens on the non-logoed area. I'm now on my 3rd PETG print in a row and no nozzle cleaning failures since.
RE: Nozzle cleaning consistently fails with PETG
With 6.3.3 I don't seem to have any nozzle cleaning problems EXCEPT with TPU, with TPU it is a total mess, fails almost every time. But I did notice one thing...
Has anyone else noticed that if you power down the printer and power it back on the nozzle cleaning works? For me it never fails after a power cycle...
Same with the bang bang bang over and over again x/y homing - that also seems to be eliminated after a power cycle... hmmm....
RE: Nozzle cleaning consistently fails with PETG
The "Nozzle cleaning" is just a mesh bed level probing in a small rectangle. If it "fails", it doesn't mean, that the nozzle couldn't be cleaned. It means, that the MBL probing failed due to loadcell signals being out of the defined range.
During Homing, it seems that the firmware doesn't just use the stall detection via the motors, but also registers the bang via the loadcell.
So for me, disabling the hotend heating via M104 S0 in the Start G-Code (search for it here), solves the banging and the nozzle cleaning issues.
Did you try this?
RE: Nozzle cleaning consistently fails with PETG
Thanks for responding.
I did not try disabling the hotend heating. But why would I prefer "mesh bed level probing" over a small sample of the bed instead of actual probing over the entire bed?
RE:
But why would I prefer "mesh bed level probing" over a small sample of the bed instead of actual probing over the entire bed?
The real MBL probing happens, when the display says "Probing". But when you look into the Start G-Code in Prusa Slicer in "Expert Mode", you'll see the MBL command for the nozzle cleaning step.
The display says it's "nozzle cleaning", but it's just a mesh bed level commands, that doesn't apply the result. It only does the MBL movement to clean the nozzle.
After that, the real MBL starts.
RE: Nozzle cleaning consistently fails with PETG
Thanks for explaining.
So the problematic code that I removed is to clean the nozzle. I can live with that. I clean the nozzle before I print.
RE: Nozzle cleaning consistently fails with PETG
Thanks for explaining.
So the problematic code that I removed is to clean the nozzle. I can live with that. I clean the nozzle before I print.
Mhh, yes and no. While you can be able to clean it sufficiently, you really need have the contact surface of the nozzle against the bed completely clear of filament, otherwise the nozzle can leave little dots during probing and even make the probing inaccurate.
What I did and would suggest instead: put the G29 command above the MBL section back into the Start G-Code, but put M104 S0 right before it.
The nozzle cleaning will 100% success without the hotend heating active and the probing will also be a lot quicker.
I did some full bed tests and I really can't see the supposed offset from the shrinking nozzle during probing (about 170°C to 120°C for me, PLA, 49 probing points).
The first layer looks completely the same across the whole bed.