Every serious metal worker will end up getting themself a roller bender at some point, but if you’re as dedicated as [Meanwhile in the Garage], you might just start building the things yourself. His heavy-duty electric roller bender, demonstrated in the video after the break, is perfect for the thicker steel and bigger radii his smaller manual machine can’t handle.
The basic concept is the same in both machines, with two fixed rollers and a third adjustable opposing one between them. Most of the components are pieces of scrap metal, and each shaft runs on bearings mounted in homemade pillow blocks. The two fixed shafts are connected together by a chain drive, and a scrap industrial motor provides the rotating power through a worm gearbox. There are two adjustable bushings on each shaft to keep the work piece aligned. The lead screw from an old car jack is used to adjust the position of the moving roller.
We picked up a few interesting tips from the video, like how to properly align a cylindrical workpiece in a drill press for drilling radial holes. He also used toggle switches as limit switches in a pretty ingenious way, and F-clamps on the work piece to activate them when it reaches the end.