Ultimaker 2+ - Fossilised hotend

[AlexM 1]

Okay, got a really weird one for the wise men of the internet. I have an almost brand new ultimaker 2+ extended (1 week old), and last night I made the mistake of leaving a print running overnight. The print failed (not sure why, just found a printer full of spaghetti), but for some reason, it appears that the hot end has somehow been pumping out pla inside of the extruder case. I think there must be a gap between the heating block and the extruder... I dont know how else the plastic could have gotten there. I have not tried to take the extruder apart yet. all the wires (thermostat etc) are cemented in pretty well and I dont want to risk breaking anything. Has anyone encountered anything like this before, and if so how did you fix it?

[neotko 1,417]

The print must have unstick from the bed and the filament started to follow the hotend. That, or you got a leak. Most probably just the first.

Easy to fix. Heat to 100-120 for pla to remove the big chunks. Then lower it at 90-100 to pull the smaller more delicates parts.

Basically heat it and maintain it until you can pull the plamonster/cthulhu.

Don't worry it can happen and it should be easy (use tools to pick it up, never the fingers ofc). Just be extra careful while pulling the area near the cables or/& use a hairdryer to control the heat.

[AlexM 1]

The print must have unstick from the bed and the filament started to follow the hotend. That, or you got a leak. Most probably just the first.

Easy to fix. Heat to 100-120 for pla to remove the big chunks. Then lower it at 90-100 to pull the smaller more delicates parts.

Basically heat it and maintain it until you can pull the plamonster/cthulhu.

Don't worry it can happen and it should be easy (use tools to pick it up, never the fingers ofc). Just be extra careful while pulling the area near the cables or/& use a hairdryer to control the heat.

 

Great, thanks for the reply. I will let you know how I get on.

[AlexM 1]

The print must have unstick from the bed and the filament started to follow the hotend. That, or you got a leak. Most probably just the first.

Easy to fix. Heat to 100-120 for pla to remove the big chunks. Then lower it at 90-100 to pull the smaller more delicates parts.

Basically heat it and maintain it until you can pull the plamonster/cthulhu.

Don't worry it can happen and it should be easy (use tools to pick it up, never the fingers ofc). Just be extra careful while pulling the area near the cables or/& use a hairdryer to control the heat.

 

So i followed your advice,  I preheated the hot-end to 120deg, then tried to gently remove the PLA.  It was stuck pretty hard so I took the fan shroud off, and managed to remove a bit from around the nozzle - the pla had gone kinda putty like from the heat.  

The rest of the "fossil" though is quite brittle, and I am worried I am having to use too much force to remove it,  I was thinking that I could up the temp to around 210 ish and leave it for a while and hope that the lump kinda melts itself off a bit?  Is that a bad idea? I also have a heat gun (a turbo 1200wat hair dryer kinda thing for heatshrink etc in the workshop), I might also be able to use that to apply heat to the further away bits?

Edited September 22, 2016 by Guest

[neotko 1,417]

Maybe it's too big for 120. Go higher and let heat expand until you can remove it gently. For the final bits 90-120 should be enough (the prts close to a hot area).

A hot gun should be fine since all the area (except the fans ofc) can handle 260C.

The idea is to pull it hot so it doesn't need force, and the bits close to metal can be 'atomic pull' without residual bits at 90-120C

[AlexM 1]

Mission accomplished! Ended up using my hot air gun, I put my soldering mat behind the hot end to shield the fans from the heat, worked a charm.

Thanks again for your help! I'm used to messing around on my crappy £300 diy printer, but i'm still nervous around my £3000 shiny printer!