Hi guys, thank you for the answers.
How can I load pictures? You need to see how bad it looks like.
I noticed that the real bad chewing happens in the end of any print (big or small running prints).
The back fun is working when I turn on the machine.
I am using 215 as nozzle temperature, speed normally 70% only and layer height 0.1mm
Last week we had high temperatures in São Paulo (34) but yesterday and today we are having maximum 24 Celsius.
At the end of every print I have to unlock all the nozzle screws, take the filament off, cut and I check the motor temperature. It is hot but I can still touch it to help screw all back together.
But the heating of the motor being high and softening the material before chewing might make sense.
I changed the machine location as maybe there was not enought cooling air in the back but the problem persists.
I can not take the filament out without disassembling all. It chews really bad. The motor runs and runs but even pulling hard it wont come out by trying the "change material" routine.
To have the lowest tension on the filament I have to keep the white indicator at the lowest position, right?