The HF benders will kink tubing before you get a tight bend,
(I have one "JUNK") and the conduit benders like you find at Lowes won't get a tight bend, the radius is too big...
For building frames you want small tight bends and to do a good job your looking at hundreds of dollars for a decent hand bender and a couple dies.. The dies alone can run well over $100 each.....
I was looking into the home made bender from Gingerys website but havent got around to building it yet..