Hotend REALLY clogged

General LulzBot TAZ
#1

Hi,

I have an extremely bad PLA clog in the heatsink of my TAZ 5’s Hexagon hotend (I assume due to heat creep?). In other cases I’ve been able to successfully clear rather nasty clogs by removing the nozzle and using a 2.5mm Allen wrench to push the clog back up, with the hotend at printing temperature. However, in this case the clog seems to be completely stuck: I’ve applied quite a bit of force and it refuses to come out.

I’ve gone so far as to disassemble the hotend, to the point where I have the heatsink with the pipe that goes in it. Using the Allen wrench to measure depths, the clog seems to be about 11mm long, starting about 15mm from the top of the heatsink. This being PLA, submerging it in Acentone will not help at all.

Any ideas how to clear this up? A Dual Extruder v3 is on its way to me but I was hoping to print a few things before Christmas!

I also wonder how unclogging the Dual v3 will work, since the filament path seems to be quite intricate, plus levelling the 2 nozzles after removing/replacing them could be a bit tricky.

#2

Seems really bad. Have you tried to disassemble the hear break as well?
For dissolving the PLA, acetone might not be best but Weld-On No3 from SciGrip, believe me, it softens it very well. The thing is that being cooked and stuck in there so bad who really knows what kind of chemical could have any effect on that.
You could use a culinary blow torch or a hair dryer in an attempt to soften it up with heat and then try again to push it out. Just make sure you use pliers instead of bare hands to hold the hot heatsink!

#3

D’Oh! You just reminded me of my heat gun. I’ll attempt it that way. I’ll also see if I can get that Weld-On stuff here in Spain, sounds good to have around!

#4

The heat gun worked like a charm! Less than a minute at 350ºC right over the heat sink loosened it enough so I could push the clog out with a 2.5mm Allen wrench. Thanks!

#5

Your’re welcome! :wink:

#6

I know the thread is old but the heatgun suggestion was genius and helped me just clear a really bad PLA clog. Thanks.

#7

Sometimes you can clear heat creep clogs without disassembling by just blocking the cooling fan while heating the nozzle to the filament temperature (or a little higher). Blocking the cooling fan is “forcing” heat creep to happen and the clog can then be pushed or pulled out (pulling preferred).