Faulty extruder thermistor ?
I am getting less than favourable prints and the occasional sound of 'popping' when printing. I believe the extruder thermistor is reading lower than the actual temperature, resulting in higher print temperatures. I am getting 'gaps' and 'blobs' as well as more than expected stringing :
As an experiment, I lowered the extruder temp to 205, down from 215 and got a better print :
Anyone else had a problem with the extruder thermistor on their Mini ?
Texy
RE: Faulty extruder thermistor ?
Incidentally the same reel of PLA is now printing fine on my MK3 at 215'c.
Texy
RE: Faulty extruder thermistor ?
I am getting less than favourable prints and the occasional sound of 'popping' when printing. I believe the extruder thermistor is reading lower than the actual temperature, resulting in higher print temperatures. I am getting 'gaps' and 'blobs' as well as more than expected stringing :
As an experiment, I lowered the extruder temp to 205, down from 215 and got a better print :
Anyone else had a problem with the extruder thermistor on their Mini ?
Texy
I would measure the thermistor once. It should have a resistance of approx. 100kohms.
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Faulty extruder thermistor ?
I am getting less than favourable prints and the occasional sound of 'popping' when printing. I believe the extruder thermistor is reading lower than the actual temperature, resulting in higher print temperatures. I am getting 'gaps' and 'blobs' as well as more than expected stringing :
As an experiment, I lowered the extruder temp to 205, down from 215 and got a better print :
Anyone else had a problem with the extruder thermistor on their Mini ?
Texy
I would measure the thermistor once. It should have a resistance of approx. 100kohms.
Good plan, thank you. I measured it today after removing the connector from the Buddy board and at 16'c it is measuring 136K. I have a spare thermistor for my mk3 and it measures 131K - do you think this is enough difference ?
Texy
RE: Faulty extruder thermistor ?
@texy
Here a thermistortable (NTC 100k):
https://www.makeralot.com/download/Reprap-Hotend-Thermistor-NTC-3950-100K.pdf
Thermistor resistance should be about 100k at 25degree C. (about 150k at 16degree C.). The deviation from 131k should be about 3 degrees. I think the temperature will not change drastically with the new thermistor, but you can temporarily connect it for testing. The temperatures are theoretical values anyway, so it is best to test them on each filament and adjust them if necessary. The same for the heating bed.
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Faulty extruder thermistor ?
I contacted prusa online chat and they had me measure the hotend ptfe tube length - it was short at 42mm. I measured the spare one which was the correct length and fitted that. No improvement with the print quality, but further investigation shows that it is that particular reel of white PLA causing the issue. My MK3 seems to handle this reel much better (although not perfectly), so maybe the Mini is not so tolerant of poort filament?
Texy