Hey Henning,

Great Work! Below body temperature is amazing for a motor that generates as much power as this one, and is so small.

Although, "too hot to touch", was probably perfectly fine as well. Humans usually find temperatures above 60C "too hot to touch", and this motor can easily run with case temperatures into the 80's. It's helpful to remember that the magnets in the rotor are rated for 150C, and the motor windings are rated for 300C. Also, we replace the rear bearing with a bearing that has grease that's rated for 250C.

This is a motor that can run quite a bit hotter than what we pattern flyers are used to.

Something that you have probably helped a little more is your ESC. The ESC can actually get very hot when running with this motor if it doesn't have enough airflow. However, I notice that you've located it directly underneath the motor case so the motor fan blows directly over the heat sink fins. This will help a lot to keep it cool, even without your new vents.

Brenner ...