I'm planning on buying just a speedbag and swivel, but I want to make my own platform and mounting brackets. Can anyone give me the diameter of the round platform, and a rough measurment of the brackets? I intend to space the brackets apart at 16 inches, so I can anchor the platform into the wall studs in my garage. Is that how most are set up anyway? Don't tell me just to buy one because I don't want to do that. I'm not being a cheapskate, but I work as a welder/fabricator and I enjoy these types of projects (and I save a little cash, too. Maybe I am a cheapskate!) .