When I decided to make a roller, my initial thought was for a very simple tool
and only for the bending of two arcs for my need to make two trusses to reinforce my sheet metal brake,
and nothing more.
But after I had finished with my sheet metal brake modifications,
I decided to add a second set roller-bases closer to the center roller,
so my tool to be able to bend circles at smaller diameters.
And after that, I said to myself, why not and a removable wheel handle for the rotation,
it is easy to made it now.