Supersize Rotary Fidget by nalanengine

Last crawled date: 3 years, 1 month ago

Here is the latest rotary fidget toy from Nalan Engine LLC. It's 100 mm OD, compared to the previous one - http://www.thingiverse.com/thing:2135945 - which was only 60 mm OD.
Larger radius for the spinning mass will increase inertia, hence it'll spin longer. Vertical ribs are removed which decreases aerodynamic drag, bridges are placed between the spherical ends which will eliminate wake turbulence. not as handy as 2135945 but spins longer. Also quieter.
It uses 3x8x4 miniature ball bearings. There are five 1/4”-20 crown nuts (10.8 hex by 7.6 tall) inside the flywheels to provide extra inertia. Print and de-burr two flywheels, and two thumb knobs. Place the nuts inside the flywheels, and glue the two halves together (use ca glue for abs). Install the bearings, the shaft & the thumb knobs.
You'll need two 3x8x4 ball bearings and one 3mm dia, 40 mm long shaft (old floppy drives have two). The fidget should spin for 45-50 sec. If you hold it between your thumb (bottom) and index (top) fingers and give it a good spin, lift up your index finger, and have it rest on the thumb only. it'll start to precess which is cool to watch.
Happy printing. Don’t forget to check out my website and awesome printers www.nalanengine.com
https://youtu.be/_Al1Ib2DuH8