1. 3d Design and modeling
I firstly design fidget spinner in 3d software called solidworks to kinda get all the measurements for later machining on the lathe. It is also very cool that you can create some realistic renderings and animations, furthermore you can determine the center of gravity and how much of a momentum does a certain spinner have.
2. What You Need for This Build
So, I got a big piece of aluminum lying around in my shop which was nearely perfect for making a fidget spinner out of it. You are also going to need: - large aluminum rod(minimum 40mm in diam.) - small rod around 20 mm in diam, - brass hexagonal rod(10mm) or a normal round one -22mm deep groove ball bearing(if you can get one with ceramic ball, that would be awesome) Using my hand saw I cut a small chunk of aluminum and 6 brass pieces of a hexagonal rod. After that I started with machining the base of our fidget spinner.
I firstly trim down the outer diameter to 40 mm and drill a 22 mm hole in the middle for a bearing. I tried to make the hole a bit smaller than the bearing so I can later press fit them in the benchwise. Next thing was to make 2 pieces that is gonna enable us to hold the inner ring of the bearing without touching the outter one. With that we can hold spinner in our hand with no problem. Now we need to make 6 brass pieces that are gonna screw on the aluminum base. On one end I trim it down to a 5mm on which we are gonna cut some thread and on the other side I give it a little chamfer for nicer look.
4. Finishing it
I drilled 6 equally spaced holes in the base and tap M5 thread in each hole. After that, I press fit the bearing to the base. Make sure the tolerance here is minimal, otherwise you may risk to compress the bearing too much which will decrease the spin time. Now we need to assemble everything together and the fidget spinner is completed. You can also make one with 4 or 2 brass pieces but you will achieve bigger momentum and longer spin time with more of them around.
Thank you for reading this instructable, I hope you like it. You are welcome to comment something you would change or add.