It looks like you don't have a pull handle,, looks like you crank down and press the roller down on the sheet between the V boards, thereby making the radius in the sheet ?? Very creative, more like a press concept,, if I am seeing in correctly ??
Or the bords the alum sheet are resting on are hinged and you pull them up as you would on a bending brake, sheet then forming around the PVC,,,,
Either way would work?
Which is it ?
Charles