Harbor Freight - Gems and Junk
harbor freight tube roller for bending tubing for such as roll bar for example.
http://www.harborfreight.com/tubing-roller-99736.html
I don't have one, but my friend has one, to bend cro-moly tubing for his chopper bike frame, for $169 plus the mount for it. it does an excellant job, but it will take lot of time. I imagine an tube bender you see on tv show cost probably at least 3 or 4 time that.
[ame="http://www.youtube.com/watch?v=FO1FOxscqqM"]Harbor Freight Tubing Roller - YouTube[/ame]
if you want to modify it and save some muscles then;
[ame="http://www.youtube.com/watch?v=OM_QyvTCsyk"]Harbor Freight Tubing Roller Electric Drive & Bottle Jack Kit @ swagoffroad com - YouTube[/ame]
I think total under $500.