I have printed the "benchy" little ship first time, with minimal lift off the glass plate at the bows, and an odd vertical (ish) line up the starboard side, essentially good for a very first print ever. Then printed two wheels small dia 30 and 20 mm both fine, both on rafts, this raft being the only change to simplify3D settings. Then tried three little wheels side by side (configured in Simplify3D) which failed, the raft didn't stick to glass, again no change the simplify3D settings. Then a single 20mm wheel, got as far as the raft then "Thermal Runaway" which I assume means too low extruder temp? Several things may be relevant..... On using Octoprint I noticed that the extruder temp set straight away at 190oC without manual intervention but the bed was initially set at 0. I tried to input the bed at 60oC manually in Octoprint it would not accept this or selecting PLA, then suddenly there it was there set at 60 so not sure if this was going to happen anyway. The fans that clip on I have sitting a small distance (lower by say 4mm ) from the X-Carriage so they will be blowing on the threaded heat break between the heat sink and the Al block holding the nozzle. I will try lifting them as high as this may have an adverse cooling effect on the nozzle. The clip on fans both come on at 40oC as expected, but after a while...may have been just before the "thermal runaway" message (which crashes the Rumba) one or both of the other fans come on (I assumed so as the noise increased) This is strange as according to the temp graph in Octoprint the temp was oscillating around 190oC just fine, but then dipped... hence the runaway message? Can't quite see the temp but I suspect it was 177oC. I will try moving the two front fans upward as far as they will go and try another print. I won't manually add the bed temp and see what happens, i.e. if it just appears a minute or two later then the extruder temp. Also could someone explain which fans can be set to come on a different temp (are we talking about the default 40oC setting?) or is the setting to run the (one or both?) fans at a different speed depending on temp? Think this was answered as the print cooling fans can be set for a speed or temp. Finally if I remember correctly the bency test piece had a manually set temp of 200 or 210 not the 190 for PLA odd as this is higher but worked with the PLA supplied. ============= Sameo sameo..... a minute or less after the print starts and before the raft is finished the print cooling fans start, the temp drops from around 190 to about 177 and the print fails with "thermal runaway" Still had to set the bed temp manually. I will take a look at the settings for temp in simplify3D as I didn't really follow the other posts as to whether the settings were fan speed related (pwm control?) or temp related or a bit of both. But it seems silly that they start (no changed from default whatever that is) soon after the print starts. I had move the heat sink fans up but that made no difference.