About 20 years ago, Rex Rice designed an apparatus for a circular motion lab experiment made from stuff you could get at a hardware store, surplus catalogs, and so on. With a little care, this apparatus works at least as well as much more expensive units from science equipment vendors.
One barrier to building this apparatus, however, is that the "instructions" for building it consist almost entirely of photographs. If you are already an experienced equipment builder and/or know your way around a machine shop, this will not be much of an impediment. But that does not describe everybody, and Rex's apparatus should be much more widely known and used. Below is a link to a PDF with my own version of the assembly instructions. They include, you know, words. If you are enough of a hands-on/tool person that you own an electric drill, then you likely have the chops to build this apparatus.