How to clean the hotend and nozzle from the outside

How to remove clogged/molten filament in a V2 head?

Obviously you can disassemble the end, which is a quite painful. It may also damage some items and threads in the long term.

Or you try whatever comes under you hand to remove the damned molten stuff in and around the PEEK. Of course, start by removing your bowden tube from it top quick coupling.

Finally, you may want to try improving your head setup, such as with the blind rivet nut.

The standard hex screwdriver

Weird, isn't it ?

The first dump tool I used was the long M3 hex screwdriver that comes with the Ultimaker...

One nice thing however is that if you leave it in place, it will transfer heat upwards in the short bowden tube, getting into contact with the solidified plastic plug. With chance, the plastic will meld again and ooze out to the head. This usually is just a temporary fix, unless you manage to remove all the plastic around to top of the PEEK.


It is somehow dangerous because that's how I created plugs also... when you remove the screwdriver, you drag some molten plastic upwards, and if it fails to exit through the top quick connector and detach itself in the short bowden, then you usually have a bigger problem than in the first place. But removing it quickly also will leave plastic behind...

So here are some other tools I use...

Push the plastic down through the PEEK with a nail!

No need to remove the coupling as here

I use it to push the remaining plastic out of the nozzle in an attempt to clean it up completely, especially at the end of my day, and even more when I printed wood (as it just wants to stay in your head!)

It works best when I leave it in place for a while, so that it gets hot enough to melt the plastic around the PEEK (will not work as much as with the screwdriver). Removing it also removes part of the plastic. I've checked that it did not go through the PEEK section, may be I could try to make the end thinner, so that I could push further up to the nozzle.

Unclog the nozzle with a thin wire

Once most of the pastic is removed by any of the other methods, I sometimes use a thin electronic wire, or the leads of an electronic component, to move dirt or hard particles out of the nozzle by inserting it from the end of the nozzle upwards (see the picture below). Such a cleanup may even be done as a preventive maintenance.

The danger is to enlarge the nozzle in the end (metal against metal), so I don't do it that often. At least I make sure my wire is clean and perfectly straight. But sometimes it works fine and drags the dirt that does not want to go through it the other way (ie. I do this when pushing hard downwards does not seem to restore a proper flow).

Use a piece of ABS to "fish" the remaning PLA

I first heard of this trick from fluxline : "to fish out the remaining PLA I mucked about inside the brass with a piece of ABS filament, the PLA stuck well without melting the ABS".

I tried by cutting myself one piece of ABS from some crap since I had no ABS filament. By letting the temperature go down a bit after heating seriously, it's easier to remove all the PLA at once compared to the hex screwdriver trick.