Once you finally get OctoPi connected, you can finally submit GCODE and get the results. There seems no easy way to do that from the front screen alone. So, once you're in this position you can tune your PID - http://reprap.org/wiki/PID_Tuning The default values supplied in e3d's Marlin firmware are: // E3D v6 (PT100, 30W) #define DEFAULT_Kp 29.20 #define DEFAULT_Ki 04.73 #define DEFAULT_Kd 45.33 Running the PID Tuning GCODE yielded Recv: PID Autotune finished! Put the last Kp, Ki and Kd constants from below into Configuration.h Recv: #define DEFAULT_Kp 22.96 Recv: #define DEFAULT_Ki 1.60 Recv: #define DEFAULT_Kd 82.38 So that looks massively different from the supplied numbers. I suspect this explains a lot about the failed initial Benchys, which failed as the fan got to 70% and suddenly resulted in a massive drop in temperature that the system was not tuned to cope with. I think I'll put these numbers in, then try one more the original Benchy, even though I think that just ramps up to 100% on layer 10. It'll be interesting to see just how noisy that is, but I have a feeling it's gonna fail. So let's see.