I designed this motor test stand for 8.5mm micro motors so I could determine which motor and propeller combo was best. This is an easy print as long as you use supports to hold up the slot that clamps on to the motor. I used an M3 screw to clamp the motor in place and a second M3 screw so that you can adjust the level of the arm on the scale.
I hope these models are helpful to you!
Watch how I use this test stand on YouTube:
The only place you need supports is where there is a gap in the motor mount.