Roller for bending flat bar

[chucketn]

Somewhere I recall seeing a write up on making a flywheel rim or maybe a traction engine wheel from flat stock by rolling it into a circle. Can anyone point me to such a build? What is that type of roller called? Any plans for such floating around?
Chuck

[f350ca]

As usual I don't have plans Chuck but here is one I made, they're called a slip roll I think.
Seams the larger the rollers the less chance of them slipping while your rolling stock, I also tied the two lower ones together with a roller chain drive. I've seen commercial ones that tie one of the bottom rollers to the top one with a gear drive.
I've rolled 5/16 plate 13 inches wide with this one. Takes amazingly little torque to turn the rollers when forming the ring.
Because of the roller spacing mine leaves about 3 inches unrolled at the end of the stock, but if I weld the ends together and roll the completed ring it comes out round.
Oh the top axle is removable to get the ring out.

[Roadracer_Al]

Nice work, Greg.

A slip roll is typically associated with sheet metal.

A pyramid roll is what you've built.

Same mechanical principles but different executions.