Hi, my experiment is not complete however I wanted to share this data sooner than later.
Filament sensor is installed and enabled in software.
A Texas Instruments LM35 is secured to the top surface of the extruder stepper motor using electrical tape.
LM35 configured per datasheet to give 10mV/C.
HP3478A monitors the LM35 circuit output.
Room temperature at start of experiment is 80F, or 26.7C.
Using the PLA that came with the Mk3 kit.
Many successful prints at the 150um setting using Slicr3. Almost no success at 100um,
A 10mmX10mmX10mm cube is the test print.
Standard settings in Slcr3 used, 150 um, 100um 50um.
Using 150um layer thickness the print was 90% complete after 11 minutes and the LM35 reported extruder temperature of 33.8C, a rise of 7C. A plot of the temperature vs. time, taken about every 3 minutes, suggests the temperature was approaching an asymptote.
Using 100 um layer thickness the extruder was at about 34C at the start of the print and was 90% complete after 18 minutes. The temperature at 18 minutes was 39.6C, a rise of about 6C. A plot of temperature vs. time suggests the temperature was at its peak.
Using 50 um layer thickness the extruder was at about 41 C at the start of the print and after 12 minutes, 30% complete was at about 43 C. The print probably failed at about 4 minutes in. The extruder was making the clicking sound. Print was terminated at 30%. Filament path is severely jammed up. Usually I can pre-heat to ABS temperature and get the "Load FIlament" to clear the PLA. Not this time. I'll take the fan off and try ABS temp again. If it doesn't clear I'll use the 1,5 mm wire method.
My plan is to repeat the experiment with the filament sensor disconnected.
In addition to using the LM35 I also placed a finger lightly onto the extruder motor. It was warm, but not uncomfortable.
The measured temperatures seem low to cause deformation?