Hi all, I upgraded my Kossel mini with a E3Dv6. I am busy calibrating and while doing so I noticed I get severe undershoot of the temperature as soon as the PLA cooling fan switches on. Temperature then drops from 205C to ~195C and rises and falls in this range during print, messing up my print's finish in the process . On my E3Dv5 I used a 40W/24V heater, on the v6 I used the supplied 25W/24V heater. The fan's airflow does flow over the underside of the heating block a bit. I was wondering; do I need to PID auto tune with the fan on? I didn't have this issue with the 40W heater cartridge so I suppose I could go back to that one but I'd rather keep the 25W cartridge.