After getting off to a promising start, I started to notice that the extruder was clicking as if the drive gear was slipping and not pushing the PLA filament as far as it should. (Post mortum examination of the PLA shows grooves and gouges from the drive gear.) At the same time, I could see that less plastic was actually emerging from the nozzle. Then, plastic was starting to ooze out of the heater block at the points where the nozzle and throat are screwed into it. Not a lot, but enough to indicate that pressure inside the assembly was building. Eventually, the nozzle clogged completely and stopped working and I turned it off. The temperature was between 195 and 200 degrees Celsius the entire time. I am using the nozzle, PLA, and other parts that came with my kit. I have not made any customizations of my own.
Any ideas about what might be causing my problem? Thanks in advance for any suggestions.
I managed to get it working with the 0.3 mm nozzle, but I have a 0.4 mm nozzle on hand if I need it later. Thanks for your help.
All what has been mentioned + never try to turn the heater block alone. So follow Michael's procedure and assemble everything before you finally tighten the nozzle. Tightening the nozzle is done with a heated hotend.
Of course, clogging the nozzle can also be caused by other things like bad filament, dirt, feeder grinding etc. The original 0.3mm nozzle also got clogged at my printer so I exhanged it with a 0.4mm nozzle from the power pack which is also more the standard size of printer nozzles.
...and PTFE tape.
Ok. No worries. This is fixable.
When everything is cool take your hotend completely apart. You'll need to clean it and make sure there is no plastic where is oozed. Then carefully reassemble it. When reassembling you need to make sure the PTFE tube goes all the way to the nozzle. The easiest way to do this is to assemble the upper portion, the throat, and the heat block. Then feed the tube till it gets to the threads for the nozzle. Tighten the coupling up top. Finally thread in the nozzle. Doing it like this will push the top of the nozzle against the PTFE tube. It might take multiple attempts to get this right because if you push the tube down too far the coupling up top won't let much get pushed back through when the nozzle is threaded in. You'll have to find the sweet spot so that when the nozzle is threaded in it pushes up against the tube to make no gap.
Next you need to make sure everything is tightly assembled. Remember, heat makes things expand. Get everything good and tight when it is cold then heat up the hotend to printing temperature. You'll need to have a crescent wrench or channel lock pliers. Make sure to be careful. You can hold bits of the hotend with the wrench or pliers and then tighten the heat block and nozzle.
What likely happened is that under heat things loosened. That along with the tube not going down and sitting flush against the nozzle it caused the plastic to melt above the nozzle and the pressure forced it out of any loose openings.