any wizzard of ooze?

Well, maybe the title is not that funny…
anyway, here is ANOTHER video from me, with my problems. And I use the opportunity to thank everyone for helping so far, the forum is great for lulzbot users (and others as well)
I will make sure to pay my tribute and pass on the knowledge whenever I am eligible

So the video is below, and we are watching PLA oozing a lot free air
Well, this never happend so far. I took down the printhead, cleaned everything etc… extruder is well calibrated, also checked

My guess would be either a temperature issue (hot end is getting hotter than it should for PLA, or a thermistor is not reporting the correct temperature to the machine) or your extruder motor is for some reason applying some force to the main extruder wheel. that’s way more PLA than you should see from just simple melt droop.

Ok… it sounds like a pretty big deal.
what would be the correct course of action? I guess I need to check both thermistor and the motor… but how do I do that?

First thing you want to do is figure out what temperature your hot end is actually at. To do that, buy an inexpensive point and shoot infrared thermometer similar to one of these:

You should be able to find one locally at an auto repair store or general hardware store. The Fluke ones are the top of the line, but spendy. The others should all work for this purpose.

Point and see what temperature you are getting, and compare that to what your printer thinks it is set at. If there is a significant difference then you start investigating the other bits.

If your printer is set correctly to 210-220c-ish for PLA and it’s still doing that, and the infrared thermometer indicates you are at the correct temperature, then maybe you have an odd batch of PLA that melts at lower temperatures, or you are printing too thin layers and getting a bunch of backpressure at the end. if you ordered your filliament from someplace that might be less than ideal, try ordering another roll from lulzbot or one of the other known good distributers.

Well the thing is, this PLA spool is from Lulzbot. It worked well before… but then i changed materials and did a little ABS… so I’ve put this PLA away… and after a month and a half I am using it again.
Could it be a problem of PLA changing properties due to exposure to open air for so long?
Oh I so hope it’s the filament issue
…otherwise I might have damaged the extruder somehow…?! By changing filaments and stuff… I might have forgotten to check the Motors Off one or two times… I don’t know

PLA absorbs atmospheric moisture really well, so the properties could have changed. Also check that you don’t have the temperature set at ABS level still. that would also cause what you see there.

Hm… I am pretty cautious about those things… temperature speed and stuff
I am sure there is no mistake there.
Also I tried to do a quick retraction after the print, to relieve the pressure, and that did the trick at least for now.

Lulzbot support should also have received my email with video by now. We will see what they make of it.
It’s fine if I managed to fix things with that forced retraction but still would like to get to the bottom of it.

Also i could try another filament to see if its something with this particular spool

What temperature are you using? I generally print with PLA starting at 180C and adjust from that point, slightly.

I am always around 180 and then adjusting.
Using 185 as average, and going up or down according to what I am printing.
For example If it is a delicate object, I go slower and lower temp. a bit. But it’s never more then 10degrees + or -

Do you home the printer prior to heating? A little bit of ooze will be occur, but will then act as a plug to keep if from doing so at the corner of the bed.

I usually don’t home Z before print, I keep the nozzle higher so that I can wipe it constantly, (OC disorder :smiley:)
It could be that the filament wasn’t kept properly so it received some moisture. I still haven’t changed the spool to check

Also, what helped a lot is to do a retraction by 5mm right after the print (important info)… that relieved the pressure from inside the nozzle. I also printed some tricky small object in 170 degrees no problem

Do you think it won’t be a problem to home the extruder when heated? Wouldn’t it clog the nozzle or smthing like that?