How did you resolve the problem? I suspect a lot of us are seeing this issue…
i haven’t yet. i need a fan replaced. however, i didnt realize the fan was bad. placing a small piece of tape and paper at the top of the exhaust ports helped me visualize what the fans were doing. when fans blow tapes flutter.
given that i have a bad fan. i think the radiator/coolers on the hotends were simply overwhelmed. I’m printing with pla. in my case the prints were perfect, till they weren’t. i would have pristine clear prints then start to get “whispy” strings at 2mm Z, which i now believe is a visual indication of the problem starting in this case. the flow is reduced and essentially the melt just oozes/drips out. a little later the print has obviously failed.
WilsonRobertT,
Thanks for your posts. I’ve been having the same problems with slight variations.
When I first got the dual extruder about a month ago, it seemed to work fine for maybe 3-5 small prints, but then the right extruder started clogging. The left extruder has also had some clogs, but ones that were easily cleared by unloading and re-loading the filament.
But the clogs on the right extruder result in the filament becoming lodged in the extruder so that unloading the filament using Snapmaker is not possible and I have to disassemble the extruder per your very helpful outline. Unfortunately that did not go far enough, and I had to disassemble the extruder even further than you went.
I’m getting airflow out of both sides of the unit, but the flow on the left is much stronger than the flow on the right so I suspect that the right extruder which has a far more significant problem, is overheating (or heating in the part of the feed tube where there should not be a high temperature) causing the filament to soften or melt before it should and that in turn is causing the clog.
For now, I’ve given up pursuing this myself and have opened a support case.
So……first off Rob I feel your pain
I am an engineer by training and I started watching this closely. My biggest mistake was thinking the fans were working as they should. Didn’t/couldn’t see the fan runnin on the right especially with the enclosure. Taking a close look at the design you can see that the airflow for each hotend should be from the side around the hotends and out the front. There is also a slight flow around the front door and hotends.
I don’t KNOW how these fans are supposed to work but I now believe that if a hotend is on the fan should be running on high. The design only works if the radiators are kept much cooler then the hotends. In testing I noticed the hotends heating and cooling are consistent. Ie. When they start to cool the hotend drops to the same temp in each cycle which tells me the hotends themselves aren’t getting heat swamp at the tips. They just get stuck with bad luck of the melt and aren’t the cause.
However the radiators absolutely need to be cooler. For this to happen in a dual print both fans need to be on high. In my case, the fan was completely dead. So each dual print failed in about the same place. The heat from the right side would cause it to fail and the heat on the right overwhelms the poor fan on the left trying to cool the whole toolhead.
It sounds like your case is similar. For you the fan isn’t blowing as hard as it should so the right side will heat up to an out of control tipping point depending on size and style of print. Then its all downhill from there.
I taped a small piece of paper over each exhaust port. You should do the same so you can take a picture of the different fan speeds, that will help support address the problem.
Of course, the real issue here is that if fans are the cause for the toolhead problem its hard for the users to gauge the operation unless the fan is cold dead. If the fan is running I believe in snapmaker engineering enough that its running right. But as we have seen, how well the fan is running is just as important. If the fan isn’t running at full then its only a matter of time and printing for it to fail. So you may not really experience the pain unless you are printing a lot of smaller parts or one bigger part that always fails.
This is damn sneaky. Hard for us to describe as a fail especially if the fan is partially running. Hard for support to diagnose for the same reasons…
Imho…the only fix here is to monitor the temp of the box area for each end around the cooler or place a probe on the hotend itself. Monitoring the temps of the box areas alone could give us an indication of hotend health over the life of the tool. If the box areas heat and cool within a range all is good. Otherwise we see them hit chaos and get overheated.
Your diagnosis looks pretty much right on to me. I’m waiting to hear back from Snapmaker support. I may invest in a couple of temperature probes to measure the radiator temps. That seems to me where the clog is occurring.
I guess there are many problems about clogging. Dont have a Artisan but toolhead is the same.
One problem seems to be the temperature regulation of the right extruder:
Are you observing the same temperatureshifting?
there is some action here with printing a new front plate
Hey there - same issue as all,when trying to print in dual mode the right hot end clogs, up to now in different cases of severity.
This morning it ended with a fully closed radiator part of the hot end.
Also tried varying the retraction settings as well as other temperature settings over the course of the prints, to no avail.
as i try prints with rather fast changes (small 12-sided die with other color on the inside) it seems to accelerate this issue of clogging up.
I’ll try to see whether the fan is also the issue for me, time to get out the thermal camera 
myA350dxfrontplate.stl (239.5 KB)
here is my update on the front plate. it will print plas in an enclosure with no fan and the front door open
Hi all,
Having the clogging issue with my 3 months old Artisan. I managed to print a lot of parts, but my problems started when I printed a large piece (38 cm) and I got clogging for the first time. Now, I have this issue most of the time. I read for many hours the threads in the forum.
I disassembled the extruder to ensure it was not clogged with PLA.
I tested with CURA and Luban from the same part
I tried to lower the temperature from 215 to 205
I tried removing the door in from of the dual extruder unit, to have better flow.
I did not try the new door design, I cannot print anymore, so that would be hard!
I saw in the J1 forum side people re-designed the hot end to fix the issue!
I’m extremely disappointed, since everything was working fine for 2-3 months of usage, and now I cannot print anymore.
I think I will open a case with Snapmaker.
You could try printing the new door design with very low retraction settings and perhaps combing mode. A smudge of rapeseed oil on the filament would help too. Maybe print that wedge thing too once you get it going…