UM2 extrusion fail

[mceep 0]

So i've been having some extrusion problems where I was getting slightly uneven printing (something other forum posts have covered). But after spending many hours with it yesterday it appeared solved so I set up an overnight print of a model that I've done quite a few times before (using the default 'High' quality setting in Cura).

Attached are the pictures of the print bed and the print head when I came in to this morning.

Anyone got any suggestions what I do next. I've not ruled out sobbing.

 

[ian 32]

Do the print table calibration test.. so you know its perfect.

THEN..

set the print bed to temp 55.

put a little glustick over the area you will be printing on.

slow the print at the beginning.. speed... 50

and you should be fine !

Ian :-)

 

[mceep 0]

Do the print table calibration test.. so you know its perfect.

 

Back up a second, how exactly do I clear all the plastic that is now decorating the internals of the print head (see photo 2)

 

[IRobertI 520]

PLA goes soft with relatively little heat. I'd use a heat gun at low power/far away or maybe even a hair dryer (how hot do those things get?). Warm it up a bit at a time and pull it off. It'll take a while I'm sure...

The two side fans come off by removing the two screws on each side. Maybe you'll be able to get those off if you heat up the nozzle?

 

[skint 61]

Hi MCeep,

Oh yes what a mess it has made. I think Ian suggested the calibration and glue stick etc, because it looks as though your print has came loose from the bed during printing, the print then can get stuck around the nozzle and cause the " blowback" lol that has caused your casing to get covered in mess.

I agree with Robert, a hairdryer may even do the trick. Perhaps manually setting the nozzle temp to 250 may help too. If necessary, its quite easy to remove the fans and the outer metal casing.

Good Luck Pal

 

[gregwar 1]

Hello,

I've already cleaned up mine, same symptoms during a big print-fail, and I indeed used an hot air gun and a pliers

 

[stuartwood 0]

Hi

I had a similar problem and solved it like this.....

http://umforum.ultimaker.com/index.php?/topic/4168-um2-printhead-clogged/&do=findComment&comment=34173

Good luck

 

[illuminarti 18]

When you get the plastic cleaned up and reassembled, can you post a photo of a front-on view of the head, so we can make sure everything is lined up properly again. :-)

 

[aaronalai 2]

Oh no, I've had this very thing happen to me with red filament! It double sucks because the print fails and the head gets filled with plastic. When it happened to me it was because the bed wasn't leveled right and the piece lifted from the bed. I didn't take any photos when it happened, I was too much in panic mode and my paternal instincts kicked in and couldn't be bothered taking any photos :mrgreen:.

I don't know if you are still dealing with the issue but I'm going to describe the steps I took to fix it the best I can recall. I did it a bit differently than @stuartwood did.

The first thing I did was remove the filament from the head; I knew I was going to have to engage the heater block a lot and wanted to reduce my chances of cooking filament inside the hot end. I performed the change material option and didn't put any filament back into the machine.

I removed the fans and taped them up out of the way to the printer head, then tried to remove the shroud via the 2 bolts on both sides of the printer head, but this piece didn't come off right away. With the bolts removed I manually turned on the heater block higher than I normally do for PLA to heat up as much of the surrounding plastic as I could. My red was printed at 210 and I recall cranking it up to 240. Let the head sit at 240 for a while and the shroud should be easy to pull off, you'll notice you'll also be able to wiggle the blob of plastic.

This is where you are going to need some small pliers, forceps, or strong tweezers; I used a surgical https://www.google.com/search?q=forceps&rlz=1C1CHFX_enUS503US503&es_sm=122&source=lnms&tbm=isch&sa=X&ei=qPhzU-7rKcfgoATklIKgBg&ved=0CAYQ_AUoAQ&biw=1746&bih=900#q=kelly+clamp&tbm=isch from my electronics toolbox. Once most of the plastic was good and melted I used the clamps to grab a hold the main blob and SLOWLY pulled it away from the heater block, keep in mind that the shroud is the only thing removed at this point. Originally when I did this I took too much of the head apart and ended up putting it back together before I had finished cleaning the shroud compartment.

With the majority of the plastic removed you will still have a layer of plastic goo on the heater block and likely still have solid plastic on the cables going to the heater block and thermal probe. After I removed the main blob with my kelly clamps I brought the temp of the heater block back down to 210. I used a https://www.google.com/search?q=forceps&rlz=1C1CHFX_enUS503US503&es_sm=122&source=lnms&tbm=isch&sa=X&ei=qPhzU-7rKcfgoATklIKgBg&ved=0CAYQ_AUoAQ&biw=1746&bih=900#q=hot+air+reflow+station&tbm=ischto direct hot air onto the plastic stuck on the wires until that too was removable with my kelly clamps. If you don't have a hot air reflow station, you may want to try and carefully use the smallest flame you can make on a lighter and intermittently hold it under the blobs encasing the wires while checking the softness of those blobs until they can be pulled away, again do the pulling very slowly so you don't accidentally pull something loose.

The wire insulation didn't stick to the plastic and once I pulled off those blobs the wires were pretty much clean, well the insulation part of the wires that is. Everything up to this point shouldn't take very long, perhaps 15 minutes. What takes a long time is wiping every surface you can while the block is hot (at 210C). I used https://www.google.com/search?q=forceps&rlz=1C1CHFX_enUS503US503&es_sm=122&source=lnms&tbm=isch&sa=X&ei=qPhzU-7rKcfgoATklIKgBg&ved=0CAYQ_AUoAQ&biw=1746&bih=900#q=kimwipes&tbm=ischbut small bits of paper towel should work just as effectively; with your tool of choice grab the paper towel and start wiping down every surface you can, getting into every nook and cranny. I used a pair of small tweezers to pull little bits of plastic here and there, and especially at the interface of the wires to the heater block. There is no need to rush this part, I just took my time and slowly but surely I got everything clean as a whistle.

Before putting everything back together I scrapped off any plastic that was on the shroud.

I hope this helps and am interested to see how your problem is resolved.

 

[mceep 0]

Thanks everyone for the feedback! I saw the first few replies and tried the heatgun/hairdrier technique this morning.

My progress was... mixed. The hairdryer didn't really work at all, it just warmed up the plastic. So I tried a craft heat gun set to low and that was much more successful, the plastic went soft enough to remove and I got about 90% of it out!

However, there was a slight downside, while warming the plastic I managed to melt the cooling fan on the back of the extruder head which is now not working. *facepalm*

My next plan is to follow

[aaronalai 2]

Hey MCeep, sucks to hear about the melted fan, but I'm glad you got most of the plastic out. If you open a support ticket or just PM Sander I'm sure they will send you a replacement fan. Sander is really responsive and can make all types of magic happen; he is on travel for the Maker Faire so it might take a little extra time to respond.

 

[mceep 0]

Thanks AaronAlai, I'll try Sander. I did (after a huge wait) get a reply from support but I'm still waiting to hear back on a replacement part.

Ultimaker support appears to respond to queries slightly quicker than a brick wearing earmuffs.

 

[gr5 2,172]

Sander and others are all at some Makerfaire or something. There's one in Bay area in california and another near Netherlands somewhere - I think in Germany maybe? Hell people told me 12 times and I still forget.