Thermal Runaway MK3s - Part cooling fan blowing too hard?
Hey there,
After upgrading to MK3s i experience a weird issue.
Slicing some testparts with standard settings and getting the new assembly to print was pretty straightforward as always but suddenly after the first layers i got a "thermal runaway" message on the screen. I checked all connections and wires and found no issue. (testslice was prusament pla with optimal settings)
After trying again I had the same issue on and on till I gave up. Every time the hotend temperature dropped from 215 degrees to 180 degrees after the first few layers.
A day later i had an Idea - what if the part cooling fan is blowing onto the heatblock and nozzle so hard, that the heater can not keep the temperature.
So I lowered the fan speed (which is 100% min and 100% max in the original settings ... strange setting?!?!) and the prints went ok again.
Is there anything wrong with the profiles or does the fan shroud have an issue?
Thanks
Chris
RE: Thermal Runaway MK3s - Part cooling fan blowing too hard?
Your thoughts were correct. It is cooling too much with new design. Decreasing max fan speed is fastest solution. Best solution is to put the silicon sock on the hotend.
Milos