Exceptionally hard clog - how to resolve?

Hi,
I was just printing in PLA and tried to close the lid after I didn’t for a long time, and run into a clog on the left extruder (most likely heat creep)

Now, I had clogs before, and I was always able to reheat and just pull the filament out, but this time, even with heating up to 250°C for 3 minutes, the filament would not move forward or backwards any inch no matter how hard I tried manually. When I introduced pliers to pull harder, it just snapped at the height of the grinding wheels, only some mm now sticking out of the hotend, making it even harder push/pull from now on.

Any idea how to resolve this clog? Any ideas why the material just doesn’t soften enough so it would basically drip out of the nozzle? (the nozzle tip is hot enough to expose some soft material) I don’t want to go to higher temp not to risk “cooking” the PLA.

Greetings, I had a similar issue with PVA, open the gear door and then remove the hotend. Pull out as much of the filament as you can and then drill out the rest using a 2mm drill bit. I went about 45mm deep and it seemed to get out the jam. Works great now.

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You can also get or make a NoClogger tool.

The one you buy is just a sharpened, 1.5mm rod on a 3d printed handle. You can heat the hotend, rod, or both and push it down into the hotend to feed clogs through (with the gear door open). Works great.

Before I got the nice one I just used a straightened piece of heavy guitar string wire. :sweat_smile:

A drill bit may risk abrasion inside the hotend :eyes:

Works fine, you are only drilling out some plastic.

Hi Rooster and Wombley,

thanks for your replies, I got it unclogged! I ordered a declogging kit for 7€ since metal rods ship for about the same price, and in the end I only needed the 1,5mm rod… but it took me 2 hours to finish the job. First, I cannot insert a hot rod in the assembled printer, since I would burn the plastic around the entry. How do you? So I unscrewed the hotend, put it next to my stove and worked the stove-heated rod slowly deeper into the mess. This isn’t very optimal since then the hotend isn’t hot and most of the time you push the plastic deeper inside rather than pulling it out.

What puzzles me is the fact that even when I had the job finished by 3/4, I reassembled everything and could insert a new strand of filament really deep till it touched the clog, even then the end of this new strand wouldn’t even become soft at 250°C, which means the clog was very far away from the area that the heat block would actually heat up.

About the drilling idea, I am afraid there is a teflon part inside that you could damage? Does everything in the standard hotend have a 2mm diameter?

Greetings, I have the all-metal hot ends and drilling out the plastic worked great.
Glad you got it fixed.

I’ve had a couple of hard jams. Heating the hotend to temperature, then using the warmed rod to push down has worked for me.

I neglected that I have all metal hotends. First homemade, then the Snapmaker ones. So for me no worry of the little ptfe section. My bad!

It does just push things down to the nozzle, but then I’m able to run some filament normally and it’s fine.

Hi,

i had my 2nd hard jam within 7 days. This time I lost patience and just drilled out the plastic. I needed the whole length of the drill to reach the clog. Interestingly, the 2mm drill worked like a charm and only produced plastic residue, no any resistance or scratching noises, and the issue was fixed within 5 minutes.

I just wonder where these hard jams suddenly come from. This time, it was just jammed at boot-up, the last print-job finished just fine oO

Greetings, what is your retraction distance.

Its 0,6mm at 30 mm/s

Hello, with PLA, I have had good results using 1mm at 35. That’s using the all metal hot ends.