I recently put in a generic all metal hotend, new thermister and new heater cartridge. I did the PID auto-tuning. I tried printing a PLA temperature tower (no extraction) and after the first 2mm it stops. I then check my hotend and it appears the filament in the heat break has begun to melt, so the extruder was unable to continue pushing filament through.
I did the same with an ABS temperature tower (no extraction), and it stops after the first 5mm. It cannot print any ABS if the temperature is above 220C. Again I checked my hotend and it appears the filament in the heat break began to melt, stopping the extruder from pushing the filament through.
I also noticed the following with my all metal hotend, which I thought may be ABS filament leaking between the heat break and nozzle as well:
However this doesn’t seem to be an issue as when after I use my cleaning tool to push the melted filament through the nozzle, I am able to manually run ABS and PLA filament through the hotend and out the nozzle.
So why can I only ever print the first few layers of my temperature tower? I tried printing a low but wide Nimitz benchy and again it started to fail as it got beyond the first few layers…
What am I missing? What am I doing wrong? I set the hotend fan to 100% to keep the filament in the heat break cool, but it isn’t working. Neither has turning off retraction helped either (thought retraction was sucking in melted filament into the heat break).