Heatbed thermal runaway due to the hotend fan
Hi guys!
I've been printing lately with PPJet (Mladeč) but I run into an issue. When I am printing small objects (like gear shafts), the hotend fan turns to 30% with the original printing profile due to the layer being shorter than 20s of printing time. This is causing the termal runaway of the heatbed very quickly (like under 2 mins). It looks like the heatbed is not able to keep the 110°C required when the fan is blowing. To successfully print the part I had to slow down the fan to 10% manually (which caused another problems later) and keep the heatbed on 100°C (even this temerature with 30% fan triggered those runaways - it falls to something about 90°C when the fan is blowing). I am sure that my components are OK, the printer is brand new and I checked both thermistor and heatbed with my el. lab equipment.
I think, this is a software problem and the PID needs to be tuned better for this. Is there a way to tune the PID or something different to do? Please advise...