I thought I'd try the troubleshooting board to see if anyone can shed any light on this, and if what I've done is OK and won't cause problems?
PID calibration - I received the PID autotune failed! Temperature too high error.
I reduced the PID drive max to 128 as per the manual - same error - it gets to 220 and climbs incredibly fast - about 2 degrees every time the LCD updates.
After a load of research, I tried:
Reducing PID_MAX in configuration.h on Arduino to 25 (from 255), dropped the PID drive max to 90, and tried a combination of m303, m303 s200, m303 s150, m303 s200 e8 and finally got it going by blowing a fan on the hot end for about 5 seconds as it reached 219 degrees, which luckily brought me back into spec and completed the PID calibration.
I've then calculated the averages for the values and entered them into the EEPROM,returned the configuration.h to normal, and returned PID drive max in EEPROM to 205. Saved, and tried to get a stable temperature while I went on to calibrate the tower heights.
My troubleshooting also caused me to think I had too much Kapton around the hot end, so I've removed a lot of it including the single wrap around the barrel on the extruder.
So far, all seems good - when heating to a set temp of 200, it spikes to 210, then to 195, then 203, 199 and then stabilises within a degree of 200 and stays there. I haven't run any filament through it yet though..
Will this have caused any problems? (especially with blowing the fan on it?) Is there any explanation as to why the heater is going so crazy that even with PID Drive on 128 PID autotune fails?
FYI, I'm living in Bangkok, so the ambient temperature even in aircon sits around 30 degrees celsius
. Thanks in advance