I manufactured a more practical and universal do-it-yourself bender. What you can see on the photos is the main base-plate with some side-straightenings and bending axes of different diameters. The location of the bearing-roll can be changed on the handle bar in a V-shape form, depending on the bending radius and the thickness of the material. The side-straightening screws have an important roll, otherwise, the radius performed doesn't have a nice, smooth arc shape. If you need to do a more complex form, you can use more vertical axes, and side-straightenings, this you can see on the example with a triangle between the photos.
When purchasing a tube bender we usually get a wide V shape rolling pair, but unfortunatly using it the tube will never get a nice bending arc. In my workshop I can manufacture for you the perfect rolling pair, already bushed, for the right tube diameter. The rolling pair on the photo has a diameter of 80mm, is also 80mm wide, bushed with bearing rolls, made for a 20mm shaft. Price: 90 € for a pair.