E3D-V6 pulling my hair out

General Hardware
1

I put an e3D-V6 (latest model with cartridge thermistor) in my TAZ 5 months ago but I am still having an issue with removing the filament when I want to change it. When I heat it up I can pull the filament a little bit (maybe 5-10mm) but then it stops, sometimes I can push it back in as well but I fight and fight to get it out and more often than not I end up having to disassemble it to get it out.

I have tried the suggestions I have received here of extruding right before pulling it out and of using retraction do pull it out and both together (extruding 20mm then immediately retracting) but nothing works all the time.

I am getting to where I dread changing filament in it and I know it should not be this way.

Any other suggestions?

Is there anything I should look at to see if it’s defective in some way?

It feels like the melt chamber is larger than the cooling section of something so you have a glob on the end that won’t go through the next chamber.

Thanks in advance.

2

I believe the melt chamber IS larger than the bore. I usually hit reverse extrude a bit before I pull mine, since mine does the exact same thing.

3

That seems odd, the drawings I see online only show it the same size (excluding the threaded area in the cooling section.

Anyway retracting is not doing it for me.

4

ive noticed this too, what I do is pull it out really fast before it has time to cool (by hand), never had another issue.

On my bowden hot end I release tension on the extruder (bondtech), disconnect bowden tube, then pull sharply, I then cut the larger section off and pull from extruder side.

5

I agree with Piercet, the chamber is a tiny bit bigger than the bore making the cold pull a real pain. I had the same exact experience with ABS over and over again. Fortunately, my choice of filament for cold pulling are the co-polyesters and the nylon bridge. Sometimes PLA works too.

For PETG and nGen, ever since I switched to E3D-V6 with the PT100 cartridge, I use 95-100degC and for the Bridge I use 135-140degC. Nylon Bridge is by far the best material for cold pulling and thus cleaning the nozzle. With the thermistor you might need to add an extra 5degC to the above numbers. PT100 is far more accurate and stable.

Disable the motors, keep the tensioner engaged, place your hand on the big herringbone gear and slowly turn it to retract the filament.
Just make sure that there is nothing left at the nozzle outlet.
If any filament string is hanging out at the bottom just pull it out.
You may also want to use your other hand to grab the filament and pull it up while rotating the gear in order to aid the retraction.
When you feel that the gear turns easily then disengage the tensioner and just pull the filament out.
It should come out pretty stretched leaving nothing behind but a clean nozzle.

6

While it may waste a little filament why not just snip the filament going into your printer and extrude until it’s cleared out then load your new filament? It sure would be easier than taking the thing apart.

7

For several reasons:

  1. It’s not actually always easier because you need to push by hand (actually…by finger!) the remaining filament past the hobbed bolt and as far down the guide tube as you can, while the extruder is at extruding temperature hot, so that you can make room for the new filament to get grabbed by the hobbed bolt and still be able to push the old one inside the guide.
  2. If the new filament works at the same or higher temps then it’s ok, you can do what you say. Provided of course that the color change is not that great, for instance black <-> white or clear <-> colored. Otherwise you need to extrude (waste) a lot just to make sure that the old color is history. You get the picture.
  3. If the new filament extrudes at lower temps then you need to go high for as long as it takes to get rid off of the old one, risking to “bake” inside the chamber the new filament and clogging your nozzle.
  4. Cold pulling results in a clean, fresh to use, nozzle ready to accept any filament you want. Also, this process reassures you that there isn’t any residue left in the chamber, including potential clogs waiting to block your nozzle. Filled filaments and some low quality ABS filaments tend to create these things.
  5. Once you get the hand of it (cold pull) then you never go back. Believe me, it’s not rocket science, just a bit of practice.