12 cents fidget spinner
A spinner that costs literally 12 cents + a bearing. Turns out to be cheaper than putting in bearings or steel balls and pennies are readily available.
The pennies are printed in the spinner no more flying pennies.
Pause the model before printing the last 2 layers (0.3 layer height) drop 4 pennies in each cavity and resume printing. Ensure that the pennies are pushed all the way in the cavity and are clear of the nozzle
Once printed use a hair dryer to heat up the bearing until warm and press it in the center.
Put the end caps on and you are ready to roll.
Note: I printed this multi color by changing the filament twice, once after the first 2 layers and then before the last 2 layers when I dropped in the pennies.