What can you make into a clock? The real question is what can’t you make a clock out of? Almost nothing. I have even tried turning my Yellow Lab into a functional timepiece, but it did not work out to well. She thought that the clock movement around her neck was going to be a tasty treat, so I had to take it away before we could start filming.
Otherwise, if you can hold something still for a moment while you drill a 3/8 inch diameter hole in it, you can probably make a clock out of it. You can start with easy things like, CD’s,