Stuck in PREHEAT stage

[a7hybnj2]

Yes, I know there is an identical issue already created #2.

The previous issue stated that it was PID settings but I have tried setting my preheat pid to:

#define PID_KP_PREHEAT 150
#define PID_KI_PREHEAT 0.05
#define PID_KD_PREHEAT 200
--
Then I tried
--
#define PID_KP_PREHEAT 300
#define PID_KI_PREHEAT 0.05
#define PID_KD_PREHEAT 250

it works 90% of the time but especially the first time after powering on the system it seems to frequently get stuck in the preheat phase.

[a7hybnj2]

maybe it has something to do with pre-heating the rest of the oven? If I cancel profile and wait until "Ready" and hit it again with the same PID settings it always works the 2nd time.

EDIT: Well I just let it cool completely to room temperature but did not power down the controller and running it again made it through the preheat just fine. I am going to try now to let it completely cool with controller powered off to see if I can MAKE it fail.

[rocketscream]

Your oven is losing heat faster than it supposed to be. When the PID is trying to reduce the heat as it move closer to the 150 Degree Celsius set point, it turns off the heat so that it doesn't overshoot much. Try insulating the oven a bit, that should help. If your oven is too big in volume, that is also one of the contributing factor. We used a 19 liter oven but anything from 9-20 liter should be okay.

It is also recommended to run the whole process once (without any board) just to warm up the oven.