QuadCan

Removing the top and bottom of an aluminum can leaves a perfect and very flexible aluminum cylinder that can be capped with a variety of geometries to create useful containers. Those geometries need not even be the same as long as the perimeter of the shape is identical to the circumference of the can. In addition, the top and bottom can be rotated to create more complex shapes.

This design uses a 12oz. (355ml) can which has a diameter of about 66mm. Aluminum cans come in a variety of diameters and this design should be scalable.

A word of caution: aluminum cans are very sharp when cut. Be careful or you may lose some blood. The removal of the top and bottom of the can involves scoring the can with a sharp blade such as a box cutter or X-acto knife. If you score it deeply enough, some thumb pressure along the score line will cause the aluminum to part. Sometimes it's necessary to cut through the can a little to get things started. Here's a simple jig for scoring: https://www.youtube.com/watch?v=pnU9kZakrCg&t=36s. If you prefer a shiny aluminum exterior finish, check out this video: https://www.youtube.com/watch?v=HHWNqxCYMtA