This is a Gyroscopic Fidget Spinner. It is made up of 3 stl files 1 for the body and 2 for the outer rings. I takes a little post printing to get everything spinning good because of the tight clearances. You can see it in action at https://youtu.be/udLh_yDoi04
After you're done printing 1 body and 3 of each of the 2 outer rings you will need (4) 608 bearings, super glue, a heat gun and a razor blade to post process and assemble the parts.
First thing to do is to clean any small imperfections from the holes on the body because the clearance between the rings and body only a fraction of a millimeter.
Next remove the supports from the outer rings and clean up any plastic left over from the support with a razor.
Make sure to take a minute and clean up any imperfections in the holes of the rings before you move on.
Now that your pieces are cleaned up get out the heat gun, bearings and super glue. Use the heat gun on the center of body of the spinner to let it expand while you slip the center bearing in. It only takes a second or so on each side to heat the body enough to accomplish this. I use the heat gun to expand the center of the body and rings because the amount of shrinkage that occurs varies from filament to filament. Next repeat this process for the inner rings making sure not to heat the rings for more than a second on each side.
Once the inner rings have cooled push the bearing a slight bit out of the ring and add a small drop of super glue to the inside of the ring and then push the bearing back in. This is important because of the multiple forces on these bearings without being glued in they tend to fly out in all directions when spun hard.
To install the inner bearing in the outer ring slightly squish the outer ring until the inner ring slides into the holes of the outer ring.
To install the outer ring in the body slide one end of the ring into the body and slightly squish the outer ring until the until you can fit the other post of the outer ring into the other hole in the body of the spinner.
Now that everything is assembled just print your favorite middle bearing cover, install them and enjoy.