I fancy building a set of rollers myself, I'm in the process of looking at getting (cheap) bearings or rollers. I built a set many years ago. I made a frame out of electrical conduit for free (well, I was at work....) and used three ex conveyor rollers. It worked a treat, but the 3" rollers would have been better if a larger diameter - 6" ? Also the rollers and bearings were steel and when I tried it all out in our kitchen it sounded like a Boeing 747 was trying to land.... after the initial shock my wife banned it, can't say I blamed her. So, I'm after nylon bearings now. If anyone has better suggestions, or knows of cheap bearings in the UK, then please let me know.