What causes burnt corners? Today I was printing some parts and I got these burn marks at the corners:



This is the first time I see this on this printer (Anycubic I3 Mega). I was using more or less the same settings (in Cura) as always, although I was using a new roll of PLA from a brand I haven't used before.

I was printing several parts in one job:



Most of them are somewhat affected:



Printing temperature:    200 °C
Build Plate Temperature:  60 °C
Printing Speed:           60 mm/s
Travel speed:            200 mm/s
Looks like overheating and insufficient airflow at the same time.

Try to reduce the temperature of the nozzle by 5-10&nbsp;&deg;C and increase print part cooling.