Rotation tool under 10€

I always wanted a rotation tool to finish my 3D prints or drill holes in PCBs. Having had a day off I wanted a "one day challenge" so I designed a rotation tool from a brushless motor and standard electronic parts. The motor is regulated via a PWM which is not included in the tool but is separate. The design was made in Fusion 360. The motivation was not necessarily to keep it cheap, but total costs ended up below 10€.

I want to emphasize that non brand motors often have different diameters.