There are plenty of cheaply made dogs wheels on the market. The Chinese have some awful contraptions on sale but they are cheap and if that is the overriding concern and not the welfare of the dog then go for a cheap one. Cheap ones cause chafing, are unstable and have nasty cheap wheels that have no bearings. Would be very interested to have a description of "Blondie.Paula's" intended construction method, how the dog will be supported and where she would get her wheels from, we had to import ours.