What type of clock? With odd items from around the house? They sell clock works at any craft and hobby shop.
How large of a clock? To be mounted on the wall, or to sit on a shelf?
Here are all kinds of DIY clocks! https://www.hometalk.com/search/posts?filter=How%20to%20make%20a%20clock
Here's one idea: https://www.hometalk.com/36897654/how-to-make-a-giant-diy-wall-clock-from-a-tabletop