3-Lobe Fidget Spinner

thingiverse

I decided to try my hand at designing a fidget spinner. I went with a simple 3 lobe design. This will fit a standard 8mm x 22mm x 7mm bearing, as found in inline skates. This was designed using OpenSCAD. Print Settings Printer Brand: Printrbot Printer: Printrbot Simple Metal Rafts: No Supports: No Resolution: 0.1 Infill: 20% Notes: I've added a heated bed to my Printrbot Simple Metal, so I could print in ABS. The pictured print is using Gizmo Dark Blue filament. I printed at 240 degrees C and kept the bed at 85 degrees C. On my Printrbot with 20% infill and 0.2mm layer height, this prints in about 45 minutes. Changing to 0.1mm layer height raises print time above 2 hours, but is worth it if you want a nice finish. Post-Printing Adding Bearings After printing you can clean up the print if you want, but mostly it's ready to add the bearings. You need four bearings for a 3-lobe spinner. Place the spinner on a hard flat surface and set a bearings level on one of the holes. Press hard using a small hard surface like a flat piece of wood. Be careful not to press on the walls of the bearing as you may damage it. Repeat for the other 3 bearings and you are done. Print Some Hub Caps It is useful to have a couple of caps that fit in the center bearing and let you hold the bearing without putting any friction on it. I printed out two of the caps from this thing post:https://www.thingiverse.com/thing:1800902 Much thanks to sLpFhaWK (https://www.thingiverse.com/sLpFhaWK) for his excellent work. How I Designed This Using Math in OpenSCAD I included the OpenSCAD file I used to generate the STL files on this thing. You can alter the variables to change the lobe diameter, length of the arms, and other stuff. I commented the code pretty well so hopefully you can follow it. The model takes a really long time to render. I think I have some weird math in their. Some values for the variables can kick up an error during rendering, but I have provided comments noting safe values to use.