Thermistor Reading Incorrect Mk2/s
I'm having a lot of trouble with my hotend. I had a large print fail halfway through and it seemed to be due to the hotend temperature getting too low to extrude. The wires for the heating cartridge and thermistor looked really bad so I ended up replacing the thermistor, heating cartridge, block, and nozzle. After I put it all back together... the hotend still won't get hot enough to extrude. In self-test, the Mk2/s sometimes passes and sometimes fails the hotend test. When I set the temp to 215C, my IR thermometer only reads the block as getting to about 90C, but the thermistor is reporting 215C. I checked the fuses in the miniRambo and they were all good. I checked voltage coming out of the Rambo to the heater cartridge and it was a good 12V (11.88).
The only thing I can think of now is a Rambo problem? Anybody else have any ideas?
Thanks!
Matt
Re: Thermistor Reading Incorrect Mk2/s
What thermistor have you installed?
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Thermistor Reading Incorrect Mk2/s
I installed a replacement sent by Prusa, so it should be the right one!
Matt
Re: Thermistor Reading Incorrect Mk2/s
IR thermometers are notoriously inaccurate on small targets like heater blocks...
what temperature does the lcd, report?
Is it possible that you have a 24 volt heater instead of a 12 volt heater? Mk2s uses 12volt PSU,
Mk3 uses 24 volt PSU...
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Thermistor Reading Incorrect Mk2/s
All the replacement parts came straight from Prusa marched to my model. LCD reads the correct temp, but the nozzle won’t extrude.
I’ll try to get a direct sample thermometer to read actual nozzle temp. I might also put a small piece of pla against it at 230 and see if it melts...
Of course, that still wouldn’t explain my intermittent self test hot end failures...
Matt