Wheel Dollies

I made my own dollies to act as both wheel dollies and with jack stands. I bought steel wheels with ball bearing swivels from Princess Auto (like Harbor Freight) and I have problems rolling them as well. The casters all seem to want to go in different directions.
You did a great job on these. If you know where we can get 16 reasonably priced casters let me know. I hate to just give up on what I have although I know at this point Id be smarter to just walk away.