problems with the hotend temperature

[Roberto]

Hello to everybody,
I just bought several Railcore II 300ZLT.
I am having some problems with the hotend temperature.
1/ The T° is programmed for 220°. When I don't turn on the fan, the T° goes up and stops.
2/ when I put the fan, the T° goes up to 220° and stabilizes.
3/ As soon as I start printing, the T° goes up to 220° the fan cuts off and the T° exceeds 235° and stops.
I can't resume another print or restart the T°.
I have to turn off the printer and restart, to be able to raise the T°.
4/ When I start the printing and put the fan, the T° arrives at 220°, then the fan is cut. The T° rises and I put the fan back on. The T° stabilizes at 220° and the printing can be done.
Do you have any idea how to avoid this problem?
Thanks in advance.

[T3P3Tony]

@roberto Please tune your tool using M303:

https://duet3d.dozuki.com/Wiki/M303

https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control

[Roberto]

@t3p3tony
Thanks, I will try.