Extruding Good-Slow-Stopped: Soft PETG in hot end (Hot End Thermistor or Heat Element)
MK2S - Hot end, holds temperature during print then cools down while printing. The display shows what the temperature should be. I am printing with PETG and have been for several months with little to no problems. Last week the printer hot end seemed to be chasing the temperature (from what I could see on the display). The temperature would go up past desired temp then the fan would kick on and cool it down, then the fan would shut off and the temp would pass the desired temp setting again until the fan would kick on and cool it down again. It would keep cycling like this for the entire print.
I started researching what would be the cause for this and came up with a faulty thermistor so I replaced it and set the calibrations and started printing again. Half way through the first couple of layers the layers started becoming very spacious and missing sections. I started over and noticed there was no filament being extruded. I pulled the door open that has the bearing that the extruder gear uses to feed the filament and I forced the filament in by hand. I couldn't get it to push through the nozzle. I pulled the filament out and noticed that it was warm and semi flexible and had a very good shape of the tip of the inside of the nozzle as if i were doing a cold pull.
I manually set the temperature of the extruder to 240, I cut a few inches off of the end of the filament and fed it back in through the extruder assembly from the top and noticed that I could push filament through the tip very easily but noticed very quickly it became harder and harder to push the filament through to the point I could no longer push it through and nothing was coming out. I pulled the filament back out and it was again warm with a semi-flexible end and the tip was shaped very well as if i were doing a cold pull.
What would create this condition and what are some possible steps I need to go through to correct it so that it's heating up the hot end at the correct temperatures and holds the temperature to extrude the filament through an entire print?
Thank you for any and all comments you have to assist in resolving this.
Jim
If you have any questions please ask, I'm sure I'm forgetting important details that would assist. ~ Thank you.