Spin it and focus at the center of the spiral for 10 seconds.
Then look somewhere else.
Objects seems to shrink or grow (depending on rotation direction).

Or hypnotize a victim and force it to wash the dishes. But always act responsibly ;)

Printing

1. Print the flywheel in 2 colors (just change filament for top layers) to maximize the hypnotic effect.

Print one of the two axis (100% infill, use brim)

• "shaft" for usage as spinning top
• or the "screwdriver bit"-axis

Use it