Recently, one of my favorite programs (LuBan 3D) added the ability to make spinners from certain STL files. Here is the Batman spinner. Now, to be honest, it doesn't spin that great, but with practice, it will spin. I have included the STL file under the Download STL/CAD Files section. This comes with a free commercial license for those who wish to sell their prints. I also have a Spock spinner.