Filament completely stuck in hotend
Okay, I'm beyond frustrated at this point and need to post here. I finished my MK2 upgrade the other night, went through calibration, loaded filament (which worked fine) and started my first test print. And no filament came out. Tried again, still no filament came out. I tried pushing on the filament from the top, no help.
Then I realized that the fan never came on when my extruder was heating up. I remembered reading (or hearing) something that if you heat the extruder without a fan it could cause the filament to jam. I took apart the extruder and sure enough there was some PLA sticking out the top of the teflon tube. I tried to take the tube out, but it would not budge. I removed the nozzle from the ... heat sync (?) and there was some PLA in the nozzle too. After some effort, I've managed to clean out the nozzle, but at this point the teflon tube is ruined from my attempts to clean it out.
Since I'm upgrading, I have the teflon tube from my old hottend. I'd like to get the new one out, but it seems like it's completely stuck. Does anyone know how to get the teflon tube out of the heat sync? If I need to order a new hotend, what's the right one to get?
UPDATE: After some research I found that I can order the heat sync off e3d's website ( http://e3d-online.com/v6-HeatSink-1.75mm-Universal-With-Bowden-Fitting ). Does the MK2 have the v6 hotend?
Re: Filament completely stuck in hotend
Joe
All Mk2s have the V6 hotend, but there are 2 versions. Early Mk2's had the V6 with glass thermistor with the screw holding them in place in the side, later ones (since about July) have the thermistor potted into a tube held in with a screw from underneath.
You should not, however, need to replace any parts of the hot end other than the PTFE tube. Heat is your friend here.
If you heat the extruder (again without the fan) it should heat sufficiently to soften the blockage so the stuck filament can be pulled out of the top with a pair of pliers.
The tube is locked in place in the heat sink; there is a small black ring where the tube exits the top of the heat sink - push the ring down and that will release the tube.
The tube from the Lite6 is slightly longer than that in the V6 and you will need to shorten it. I would suggest inserting the new tube upside down, but cut the end square before insertion and ensure that it is fully home in the tube before locking in place with the black ring. Insert the extruder into the plastic parts and then cut level with the top of the plastic feed hole.
Full instructions can be found here: http://wiki.e3d-online.com/wiki/E3D-v6_Assembly
The key to doing this is to calm down and take your time, I do know how frustrating this can be...
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Filament completely stuck in hotend
Thanks for the advice! It's all back together and calibrating. Hoping to do my first test print soon. Already checked that the fan is connected properly and turns on at 50C like it should. Here's hoping for a good print!
Re: Filament completely stuck in hotend
It prints! Well, the head moves and it extrudes. Sticking to the bed, that's another story for more forum research. In the meantime, in case anyone else runs into a problem with filament jammed in the heat sync:
Do NOT keep forcing it. Just do what PJR said above. Heat up the extruder, take a pair of pliers and try to pick it out. If you can't reach it, very carefully use pliers (the ones that came with your kit work well) and turn the heat sync off the hot end. This takes some serious patience, as you cannot use your hands unless you want to get burnt.
Once the heat sync is off you can use something blunt and thin to push out the softened, stubborn filament. I used a hex screwdriver that was about the same diameter as the tube. That did the job!
Re: Filament completely stuck in hotend
Same thing happened to me. After building my kit I was calibrating the Z offset with some greenish colored filament. It was really hard to see how well it was sticking to the bed due to the transparency of the filament. I ended up getting it too close and so the filament couldn't flow well. I panicked a bit thinking I was gouging the PEI (turns out I didn't thank goodness) and so I cut the power. This is my first experience with an all-metal hot end, and so I was not really thinking about how cutting the power to the heatsink fan with the hot end at 210 degrees would allow heat to creep up into the cold side of the E3D. I had to take the E3D out and remove the hot block to get to the plug of melted PLA inside the heat sink.
Once the plug was out, I reassembled the E3D, heated it up, and cleaned out the nozzle with a tiny drill bit. Works like a charm now.