Hello,
I have problem with Marlin 2.0 on my Prusa clone.
I have Precision Piezzo sensor - so to have good Z zero reading I have to preheat the nozzle first.
If the nozzle is on exact temperature and I start printing (I'm using Octoprint) the printer perform all commands from initial Slic3r G-Code until line
M109 S265 ; set temperature and wait for it to be reached
then temperature start oscillating until heater timeout is triggered.
You can see this on picture attached Oscillating01.jpg.
If I lower the Hotend teperature by say 20-25°C then start printing - there is no problem. Temperature reach target level and there is no oscillating.
This same phenomenon I have with M600 command. Printer has fillament run out detector, sometimes I want to change color using M600 - it's very, difficult because very often I get oscillating problem see picture Oscillating02.jpg
The trick to to rescue the print when temperature is oscillating, is to somehow lower the hotend temperature by 15-20°C (strongy blowing or touching heated block with wrench). If I'm lucky I can have print resumed if not, I just have temperature run-out error.
I was trying PID tuning - same situation. But I thing that problem is somwhere else - As you can see on picture attached Oscillating01.jpg Hotend target temp is reached almost perfectly (in PID meaning). Maybe the D factor should be a litte stronger - but lower D - means les chances to oscillate.
Any idea where to start looing for help?
best regards
Slawek
