Thermal Runaway
I have recently starting having an issue where my print gets a Thermal Runaway error. I built my MK2 in March of 2017 and haven't been using it for very long. I just finished building an enclosure for it and that seems like it may have been the trigger for this problem. But when I tried doing a print with the door to the enclosure left open I still was having the same problem.
Watching the temp readings on Ponterface should the temperature bouncing from 215 to 67 and everywhere in between. I can't get a good reading until I restart the machine and the last time it came up as 300C and there was smoke coming from the extruder tip.
Is this an issue with needing ventilation for my enclosure or something electrical?
Re: Thermal Runaway
If the temperature reading is bouncing around that could mean an intermittent connection between the thermistor and the control board. Good luck diagnosing!
Re: Thermal Runaway
Definitely a bad connection with the splice on the thermocouple to the Red/Black wires that go from the extruded to the electronics. My MK2 (also received in March) broke there too, but it was due to me being agessive with a cleanup after a failed print. I needed to replace my thermocouple, and re-solder. I then added some mechanical strain relief on each side of that splice in the form of a dab of silicone to ensure it was not being mechanically stressed during printing. So far so good.
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Re: Thermal Runaway
I doubled check the connectors on the Rambo shortly after posting here and did find some loose connections. I have reseated everything and haven't had any problems since then.
I will probably still add a vent fan to my enclosure so that I can run long prints without working about the temperature.
Re: Thermal Runaway
I thought temperature dropping is a bigger issue than overheating, and the enclosure is supposed to help, not make it worse. But I'm a noob, maybe I am understanding this wrong?
Re: Thermal Runaway
In this case my temperature issues were related to a loose connection on the RAMPS board. The enclosure can be helpful for temperature control but that's more of an issue when printing with ABS which I haven't tried yet. I built my enclosure to keep my cats away from the printer.
I was having problems with the extruder temp consistently going over and then under the target temp by 5 degrees in each direction. But I fixed that by retuning the PID loop.