That time of year again

A follow-up, of sorts, to

Back around March, I finally got the A350 to reliably produce usable prints without failure. Things were humming along well until yesterday, when a print that had been running overnight failed - the machine was printing air for hours. Thought it was a badly-wound filament, tried a different but similar print, same thing happened. Carefully examine the filament in the print head before extracting it, and saw a nice mushrooming of the filament below the spot where the extruder gear was chewing it up.

That’s right - humidity is back.

I kicked on the dehumidifier in the room and it claimed the room was at 70% humidity. I chucked humidity gauges in the filament hotbox and the A350 enclosure and they were 40% and 60%, respectively. I chucked dessicant in each, which brought them down to 20% and 40%, and after running all day the dehumidifer brought the room down to 45%.

Ran the original print last night and it just finished. Back to reliable printing.

Man, this stuff is finicky.

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aaaaaand the 3D print head clogged four days ago during a simple 4-hour print. Gotta take it off and replace the hot end. Good excuse as any to finally put the dual extruder on.

Dehumidifier in the room is on a timer and wasn’t running, read 70% when I kicked it on. Filament box read 60%, I didn’t bother with a reading inside the printer enclosure.

Time to put the inline drier back in the setup. Or face the fact that I can’t do 3D printing between June and Oct.

Maybe another reason could be that some of Snapmakers products (all of them?) seem to be balancing on the edge of working/not working. What materials are you having this issues with?

Pretty sure I can pin this one down on the humidity.

The clog happened on the third spool of 3D Fuel PLA+ since I rebuilt the A350 with linear rails on all three axes and the puportedly-quieter linear modules. This is notable in and of itself - I think prior to this I only printed two full spools of filament in the past two years, and half of that was likely test and calibration prints. I never had the A350 work so consistently before I rebuilt it.

Very wet spell for about week here, and the clog happened right in the middle of it.

I have a Kingroon cheapo that I picked up to use when the A350 is down (kinda like a loaner!), and that thing has been unusable since early May when I foolishly kept on using it without an enclosure. Blobbed the head and chucked the entire thing into a drawer in disgust. But it never printed anything larger than a 2" cube without something going wrong.

Ok well, maybe you live in the rainforrest but were I live, I can print all year around. Even on hot summerdays. Are you sure it’s the humidity and not the hot air making heat creep more likely to occur? Maybe you could start using a dry box and a filament lubricator? That way, you would lessen the effect of both of those problems. :slightly_smiling_face:

Got a drybox already. Could be heat-creep I suppose; the slight mushrooming of the filament I took to be a side effect of the filament expanding with moisture inside the printhead, as this happened in the past, but I did not get out the calipers to measure the difference between the drybox and the extruder. But the printer ran fine through a hot spell (90F) two weeks prior, and the rain brought temps down the fifties (F) again. My fix last time was to run a portable (1L?) dehumidifier inside the enclosure before a print job, amd renew the dessicant packs once a week.

House bordered by wetlands on two sides. Pond twenty yards away and a lake about 200 yards away. Lotta water around here.

Ok. but if you’re printing PLA, have a dry box and preheat the roll long enough and hot enough there should not be a problem even if the air is very humid. Pretty sure that PLA don’t absorb moisture that fast. I’m pretty sure a filament lubricator with a pinch of rapeseed oil would help. Maybe not solve the problem completly, but it’s possible… Did you ever try that?

Did not try a lubricator, no. Have t change quite a bit of the setup to try that out - I made a custom filement inlet that takes a coupler do that I can have a bowden tube between the (yes, heated) drybox and the print head.

What susprised me the previous time was the expansion of the filament inside the print head. Calipers showed it on size at the bowden tube inlet, and oversize below the extruder gear. Consistently, not just a section of bad filament. Maybe it’s not humidity, but extreme humidity countermeasures seem to solve the problem.

Or at least they did last time. I haven’t had time to work on the A350. It’s like a yacht, or one of those sports cars, that spends more time in the shop than in use.

I had intended to print a prototype this past weekend and mail it off for a test fit. With the A350 down, I’ll just skip that step and machine the actual part. Like I did before I decided to improve my workflow with a #!$@* 3D printer :wink: