Hi All,
I have searched the forum for help on this but did not see much advice. I am seeing repeated clogging during prints. All my printing has been with Snapmaker-supplied PLA so far. I used one reel of black with no clogging issues. I have started a reel of white and printed a temperature tower successfully. I started a bigger print (about 40 hours I think) and the nozzle clogged about halfway through. I cleared the clog with a thin piece of wire (one tip I found in these forums) and printed a calibration cube and a small mechanical part succesfully. Those successful prints represented about 4 hours of work I think. I started another long print and the nozzle clogged again after about 8 hours. Again I could clear it with a piece of wire and I can easily push filament through by hand when the nozzle is above about 190°.
Questions:
1: The hob gear that drives the filament has a bit of PLA debris in it after grinding on stuck filament. Should I be trying to clean that out somehow?
2: Is there anything different about the white PLA compared to the black that would be causing clogging? On the temperature tower I printed I didnât see much variation in quality between the rungs.
Iâm printing at Normal quality with zhop and retraction, a skirt, extra extrusion and slower motion on the first layer. I have tried printing at 200-215° so far with the white PLA.
The PLA reel goes into a dry bag between prints to avoid humidity buildup, and it is not in a dusty area. The packaging for the reel was first opened about 4 days ago.
Thank you @xchrisd - this is really interesting. I will try retraction distance of 1mm as you said (was 5mm before). I was resisting the step of changing the nozzle as it has so few hours of use on it, but I see your point that there could be another reason to change it.
Quick update - I started a new print with 1mm retraction distance, and everything went well at first. After about 1 hour the nozzle caused the print to detach from the bed and started dragging it round. I assume my bed is not flat enough to support 1mm retraction distance. I am starting a new print with 1.5mm retract.
Hi @Potter, the filament clogged inside the nozzle. I took an overall photo that included the nozzle after one of the fails and you can see the nozzle area in the attached image.
. There was a bit of PLA on the outside of the nozzle but the bottom of the nozzle was clear.
The latest print ran overnight and finished successfully. I think it helped to reduce the retraction distance (the original setting of 5mm must be excessive for PLA) and I have a better understanding of retraction distance vs Z Hop now. Thanks again to all (including @xchrisd and @Isaac11) for lending your expertise.
This happened to me too. Never had a clog with the SM black PLA, but I did with the white PLA. Using mostly default Fast settings when this happened to me.
Of course I was in the middle of a large print and when I went and checked on it this morning, it was clogged again! I will try some of the tips for the next printâŠ
Edit: so I am unclear from the discussion above, Z-hop should or should NOT be activated? My settings were default (5 mm retract, Z-hop off). I am setting retract to 1 mm and enabling Z-hop. Tell me if this is wrong!
Less retraction is better for the print quality till the point where it is too less.
I would suggest you, just to enable z-hop when it is necessary (different models on the build plate and far travel paths, if there could collidate something).
I never had clogging problems with my retraction settings, except of my broken tube in the hotend.
I think you should do some research where the clog comes from, here are some examples:
just filament got stuck in the nozzle, classic (maybe because of too far retraction)
temperature did not reach on the nozzle
print-temperature too low
grinding the filament with the extruder gear- so no clog- this is filament grind (too fast print, too many pressure, too cold,âŠ)
clog because of dirt (is your filament old, dirty and or dusty, is your environment clean)
I am executing a 12 hour print with 1 mm retraction and 1 mm z-hop right now. It didnât seem to add much time to it (z-hop that is). So far it has not failed. I donât really see any of the factors you mentioned being the issue.
When my job first started failing, I noticed it was âprinting in the airâ with nothing coming out. I manually pushed the filament by hand from the top until the gear engaged again and it was extruding. So it was gear grind, but I think as soon as it stops, that is going to happen. Filament was extruding at this point, but I could see it was too far above the print to complete successfully, so I aborted the print. Then with the filament head up in the air and nozzle temp set to 205, I opened the hatch to disable the gear drive and manually pushed the filament again. I got a little squeeze out, but not full volume, then it completely clogged and nothing would come out with the pressure I was able to apply manually.
This was when I swapped out the nozzle. The new nozzle worked fine until it also cut out in the middle of a print which led me to where I am now with reduced retraction and z-hop enabled. I donât think these jobs are particularly challenging but they are very large area (8-1/2 x 12 inches), though not very thick (1/8 to 3/8 inches max), see image. I am having a little trouble with leveling. The A350 bed doesnât seem very flat and even with a larger calibration grid, I still feel it isnât fully compensating for the unevenness. I am thinking of âgoing glassâ!
Just an FYI followup - that print and another just like it completed without further clogging. Not sufficient proof that 1 mm retraction plus z-hop is the cure all, but it seems to have worked for me.
Now I plan to print these in ABS. I need my enclosure!
