Taz 6 Thermal Runaway

So I have been printing with my Taz 6 for a couple of weeks now and have been pretty happy with it.

Well today I was printing the jaw from the Makerbot T-rex (http://www.thingiverse.com/thing:308335) and at 98.5% it stopped printing with the LCD displaying “THERMAL RUNAWAY”. Printing with Village Plastics ABS, using the “High Detail” profile in Cura. Extruder temp: 240, Bed temp: 110, Fan speed: S127 (49-50%).

A quick forum search suggests that the issue is that the fan duct design is cooling the extruder too well.

Should I be concerned about this? Would I be fine with trying to print the same file again?

I too have just started having this problem with my TAZ 6, also printing ABS.

Is there a trouble shooting guide for the thermal runaway issue?

The Thermal runaway code is designed to shut the printer off in the event that the heater core falls out of the heat block. It’s basically designed to stop the printer if Expected Temperature based off amount of voltage sent to the printer is lower than actual detected temperature. If you have too much cooling on the hot end heater block itself, the temperature can drop too fast and trigger the code. A failing heater block can also mimic the issue.

troubleshooting would involve removing any modified ducts, replacing the heater core, etc. Or since you are under warranty you can call support

Okay, this is an interesting topic. I’m in the process of upgrading my Taz 5 cooling fans to the Taz 6 design. I printed out the parts last night, but still need to print the extruder fan mount. I’ve seen a couple of designs, the one from the AO site is pretty much just a fan mount w/o a duct. It seems the designs that include ducting may be over cooling the hot end too much?

Do you find disadvantages to simply using the fan mount w/o duct? It seems to me that sans ducting could cause print cooling too since the hot end fan stays on, that’d be okay with PLA I guess, but would it negatively affect filaments like ABS?

I really respect your design expertise piercet, what design do you use?