Bending parts requires a few extra thoughts in the design and layout of the flat patterns, so if you want ... force required to bend a part out of sheet metal down to something you can handle ...

The underlying problem for sheet-metal parts, says Bucalo ... DXF files that include two layers, one with the flat or unfolded pattern, and the other with a 3D wire-frame model of the transition.

The process at work here is, relatively speaking, pretty simple. You print out the upper and lower die, put a piece of sheet metal between them, and then smash them together with a hydraulic press.