Well, a little late to the party on fidget spinners, but now that I’m hooked might as well throw my take on them into the pool.
These are designed for minimalism print time & plastic use wise, all will print in about 10-15 min and are designed around 2 perimeters of a 0.4 mm nozzle for a perfect thin yet solid band around the bearing. Infill can be set to whatever (I used 20%) as it will only be used a little bit in the space between the bearings.
Big Mama (50 grams) is designed for big hands, with a spin clearance radius of 43 mm
Little Daddy (49 grams) is designed for smaller hands, with a spin clearance radius of 38 mm
The Cheap Skate (45 grams) is my attempt to push things to the minimalistic limits, by using very little plastic and M10 steel Nuts as the outer edge weights. The CS has a tiny spin clearance radius of 32 mm for the smallest of fidgeting hands.
The Typhoon (78 grams) is simply an extension of the Cheap Skate pushing the spin clearance radius out to 47 mm and adding 3 more nuts for mega spin times.
The bearing plugs where something that I added at the last min after the photo was already taken, they are just a slug that presses into the outer bearing holes adding a tiny bit of additional weight/color.
I quickly discovered it’s pretty much all about mass and that masses distance from the center point, combined with balance and limiting friction as much as possible. However there is a bit of physical limitations mixed in, where you can only go as big as your hand allows.
Few things to think about.
While ceramic bearings are apparently the best, not all ceramic bearings are equal, so don’t get too caught up in that hype, unless you can afford to. I am using hybrid ceramic ball, metal housing bearings and its fun enough.
Remove any grease from the center bearing using a de-greaser solvent like wd-40, its debatable whether or not a little lite oil after the de-greasing is helpful, I have been using a tiny drop of PTF based tri lube, I don’t notice much of a benefit or a drawback though.
There is no reason to use the expensive bearings at the outer edges, just use cheap-o bearings everywhere other than the center bearing.
Whenever possible remove the rubber shielding on both sides of the center bearing as it only adds friction, however once exposed dust can cause friction issues too, so always use a finger guard plug after removing the bearings shields. Finger guards are good anyway as they help to avoid accidentally touching the bearing and slowing the spin.
All of the spinners in the photographs where printed on a MyOpen3D Seattle Prusa i3+ 3D printer. https://www.myopen3d.com/
PLA, 0.4 mm nozzle, 0.3 mm layer height, 2 walls in all directions, 20% infill.
These are designed for PLA and to be extremely snug when pressing in the 608 bearings, if you find them too snug you might be over extruding a hair so just drop your flow factor by 1-5%.