Super Heavy Metal Spinner

thingiverse

To make this spinner work, metal must be cast into a sand mold. Note that using lead is not ideal because it's toxic, especially when you melt it and inhale the fumes. Tin might be a better choice instead. The reusable form comes with a small handle and is designed for creating an open mold. Once set up, some light sanding should even out any weight differences, allowing the spinner to spin smoothly. The provided cap is quite concave, so it needs to be printed upside down with support material. Alternatively, you can use any other cap that fits the 608 ball bearing. It took me around five minutes and thirteen seconds to reach spinning speed (hand-speeded up, no compressed air was used).