I claim this to be the world's first hand held fidget spinner with bevel gears!
This toy can be:
rolled around on your palm.
held on two corners on the center-hub and watch all 8 gears spin in synchronization.
held on two opposite-face gears and watch the middle 6 gears revolve.
and maybe discover more ways to play.
For mathematically / geometrically oriented audiences: The toy comprises of 8 bevel gears arranged as a surface of an octahedron. The center hub is a truncated octahedron.
Note: this is not meant to be a high RPM or a long spin time fidget spinner. This toy is an object to enjoy the mechanical motion of the gears. Print, assemble, and have fun!
Things to Print:
1x CenterHub.stl
8x BevelGear.stl
8x Sleeve.stl
Thing to Purchase:
8x 625 Ball Bearing (ID = 5mm, OD = 16mm, T =5mm)
8x M3x20 Flathead/Countersunk bolts
8x M3 Nuts
24x M3 Washers
To Assemble:
Assemble total of 8 Gear Sub-Assemblies. Follow the images for details. The sleeve is inserted inside the inner diameter of the bearing- the sleeve is there to keep the bearing and gear aligned. The two layer M3 washer is there to provide 1mm spacing between the bearing and the gear. (Washers and sleeve can be substituted with other things, if you find a better part).
Insert the ball bearing end of the Gear Sub-Assembly into the hole of center hub. The hub is designed so the bearing is friction fit. A file or glue may be needed depending on your 3D printer.
Tip:
I found that the bearings spin better if degreased. I used ethanol, but other degreasing agents (IPA, acetone, etc) may be used.
