Dynam Excalibur - Motor mount enforcement

This mount get more stability for the torque of these big motor.
As you can show in the internet, some users had bad experience with broken mounts while flying.

I have changed the inner diameter to best fitting with the prop holder.
The air intakes have chamfers now, for a better air circulation.
More material against the original one increase the stability a lot.

The screw positions of the motor against the prop holder aluminum part does not match properly.
So, you have to grind two i