There are low cost universal joints available from McMaster-Carr.
For $11.00 to $14.00 you can get a nice, no slop, universal.
Put in " Low-Speed Pin-and-Block U-Joints " in the search block at this link
http://www.mcmaster.com/
By the way if you can get a hold of one of their catalogs they have everything you could ever need for building anything you can think of.