Hi,
Thank you for your detailed feedback.
I’ll answer point by point.
- The photo you see here is my latest try with reduced cooling and higher nozzle temp. I had other tries with no warping (mostly with default settings ). I’ll do a test cylinder to explore your idea.
- I’ll do that with a test cylinder and upload the results. Faulty thermistor could be a good idea.
- I didn’t disabled it completely. I can try.
- No, but i tried slower wall speeds.
- Layer adhesion is bad on tyhe whole model. 2mm thick shell all arround. I’ll work with a test cylinder with a 2mm wall to do a sample part.
5-2) Door and lid were closed, same as my X1. My X1 is in the same room, and both printer are on the same table. Environement is the same, material is the same, part is the same, result is different.
Update : Increasing the temperature to 280°C seems to give good results (like said on you point 2). I’ll investigate the thermistor.
Update 2 : Inspecting the hotend show dry grease. I changed the thermal paste and reasembled the whole thing (see pictures)
Update 3 : After thermal paste change sample parts are OK at reasonable extrusion temp (220deg). But they are great at 230-240°C (which is still high for a PLA) I’ll try the whole initial part.
Update 4 : Problem seems to be solved. It was due to dried thermal grease. Kind of bad for a brand new printer 
Thanks a lot @Olias for putting me in the right path !