Welp, it’s a long weekend, and that means my nozzle has to get jammed. I opened it up to find a bunch of charred blackened stuff filling the rest of the hot end, and ended up drilling it out. I must not have cleared everything, however, because although the filament (PLA) goes through to the nozzle, it’s getting jammed there. Pulling the filament out while warm isn’t getting me anywhere so far. I’m a little leery of taking a drill to the nozzle itself. Any ideas for cleaning this part out?
Acetone. It’ll make a gooey mess of any plastic in there. Leave it overnight, immersed, and brush it out in the morning.
Damn. No acetone in the entire house. Time for desperate measures.
You’re probably going to think I’m nuts, but I just tried dousing the nozzle in boiling water, and then subjected it to the steam from an espresso machine’s frother wand.
Then I jammed a piece of 3mm filament in there and scraped the whole business out. The result is a (possibly) less jammed nozzle in need of a good bottle-brushing.
(Picture #2 above)
i helped someone unclog a nozzle with an adjustable temp soldering iron and an air compressor. Left the tip on the soldering iron to melt and soften what would come out on it’s own and air compressor to violently get rid of the rest.
Small propane torch (and some pliers) always works for me. Acetone doesn’t help all that much if you have PLA in there.
@Jim_Squirrel @Brian_Evans : Both sound like better ideas than what I did. 
My nozzle was clear for about 20mm before jamming again. Maybe I’ll pull out the soldering iron next.
I have an Up Mini, which is fixed at higher temperatures (damnable vendor lockin). I had some third party PLA jammed in there, burned, so I put it up to the ABS temperature, and fed some Up! branded ABS through. It unclogged the nozzle somehow. It probably could have done far more damage…
sigh that hotend is now officially toast. Broke the heater trying to remove the nozzle. I suspect I didn’t get all the gunk out before reassembling it, so now it’s glued in place.
Anybody know of a good wades-compatible 0.25mm hotend? I’m in the market.
well there are so many new all metal hotends out there that have potential to eliminate the clogged nozzle problem. The prusa nozzle and trinity labs metalmagma and the e3d are shipping now and the pico is in the works.
Ahhh the fun of the ceramic MG heat core. That sucks! Had that happen to me too. Rick is promising a new MG all metal hotend but havent seen anything yet.
btw i forgot to mention the ecksbot Hot End. it’s been on the block for a while.
I like the new all metal hotends, especially because I want to print PC one of these days, but it seems like hardly anyone but makergear offers 0.25mm nozzles. And I do like my 0.25mm prints so much… Maybe I can salvage what I’ve got left here. I actually have an extra ceramic core, so if I got a new nozzle and turned tube from MG…
Either that, or maybe I should get that mill and start machining my own hot ends. That’d be the efficient thing to do, after all.
My 2 cents suggestions:
A) The hotend is clogged only with PLA
-
Send it to 200C and push inside the filament manually (of course it will not come out…)
After 4 minutes you are sure it is well melted inside. Then:
Turn off the heat in controlled way (e.g. you should have the realtime hot-end temperature displayed)
When you see going down around to 165C firmly pull up the filament. Your platic should be enough solid to get out in a single bock, and 90% it will get out the blocking piece that has melted inside the other PLA. If you get a filament, then you were not cold enoght, try again waiting for a lower temperature (e.g. 160). This may vary based on the specific PLA componennts. -
If all this fail, drop the hotend in a solution of caustic soda and water at 60C. If you have a small jewellery ultrasonic cleaner, put it there for 3-4 hours. Otherwise leave in the solution for more. Then rinse everything. This procedure requires carefully handling, safety glass and glovers, since the splasher of the solution are extremely corrosive for human body. Also dress should be adequate.
This should dissove any block in the hot-end.
B) The hotend is clogged only with ABS
- Drop in acetone for 3-4 hours, and it should dissove anything.
C) The hotend is clogged with PLA and ABS. Then you should use both methods.
The point is that from the picture I see, this kind of hot-end is not the type of hot-end you can dismount till having only a metal part that can be dropped in solvents (Acetone or Caustic soda) ! If you are not able to remove the hot cartridge with wires and the temperature sensors they will be damaged by Acetone or Caustic soda!
@Roberto_Coli Actually, the thermistor you see in that photo is just kapton-taped on (it’s a standard makergear hotend), so I could douse the whole thing. Your advice is good. I actually started out with the temperature cycling and using the filament to try to get it out. I think the PLA I had in there was already too charred to stick to the new filament. It was completely blackened, though it had once been a nice bright yellow :-).
Now, of course, I’ve gone and fused the nozzle to the tube with plastic, and scraped up the threads with my pliers trying to break it free. I probably should have gone to buy some solvent instead of going for my drill, because I think part of my current problem is due to debris and scratching of the inner brass tube. Ah well, the violent approach isn’t always the best one.