I have a Wanhao Duplicator i3 v2 (A.K.A. Maker Select, Cocoon Create).

My extruder got clogged: I noticed that it wasn't extruding, so I stopped my print, removed the fan, heatsink and the extruder motor and I saw that the clog is at the heater block level.

This is a what I have:

Blocked extruder - no flash

Blocked extruder - flash

As you can see, there is some PLA clogged at the very beginning of the 1.75mm hole in the extruder block.

I can see there is something white inside (a stone? something that is not PLA?). I tried to heat up the extruder to 250°C and pushing with an hex tool but the block did not move.

I solved a lot of clogged nozzle issues with the cold pull method, it always worked like a charm, this time I tried too but as a result the PLA filament broke and the "stone" is still there.

Does anyone know if there is a way to unclog the extruder in this situation?

Do I have to change it?


3 Answers 3


I'm sure this is not the best solution, and if you have some ethyl acetate you should try that before going "the hard way".

Ethyl acetate is a solvent for PLA, so if you soak the extruder into it PLA should melt and free the extruder.

That said, this is the "hard" solution that worked for me.

You'll need:

  1. A drill
  2. A 1mm drill bit
  3. A 1.5mm drill bit

Insert the 1mm drill bit into the drill. If your drill has a setting to reduce the drilling speed, take this to the minimum speed. If your drill doesn't have such options, you'll need to push the drill button very gently.

Put the drill bit on the pla block (be sure to not touch the cooling block, you might ruin it). Start drilling at the minimum speed and push very gently, until you get a side-to-side hole on the PLA (you know it because you feel no resistance at all while pushing the drill).

Take the 1.5mm drill bit and repeat the same operation. At this point my PLA block literally exploded (now I have some broken PLA inside my room, don't know where) and the extruder was finally free.

I hope this helps someone. Please notice that you need to be very gentle in order to avoid breaking parts of your extruder, but if I managed to do it, you can do it too ;)

As previously said, if you have ethyl acetate try soaking the extruder into it to make PLA dissolve before trying this. Try this solution only if all other options didn't help.

  • $\begingroup$ I've used similar techniques but with a pin-mount handle. That way you can rotate the drill bit very slowly and with minimum pressure. Retract regularly to clear the bit of loose material to avoid jamming. $\endgroup$ Commented Jan 30, 2017 at 15:41


  1. Take the tip off, assuming it has a tip.
  2. Heat up the extruder.
  3. Take a length of plastic and push it though the extruder.
  4. If the tip is clogged, then take a micro hand drill to clear the blockage.

This may not help, but I have a printrbot and when it clogs I heat up the extroder to 210C(for pla) or whatever the normal temperature is. Then manually push your filament through the hole till it's as far as it can go, then drop the hotend temp to 100 degrees C. When it is at 100C pull the whole filament out and hopefully your clog will come out too. After that just cut off the end of the filiment that has the clog on it. And you're good to go.

  • $\begingroup$ Thanks for the answer, but as I wrote in the question I already tried the cold pull method (= the one you described), and it didn't work. $\endgroup$
    – BackSlash
    Commented Jan 31, 2017 at 16:40

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