Make two J-bolts to fit your steel pipe. Round up a sheet of plywood, some sheet plastic, and the good duct tape. Drill holes to fit the j-bolts near the edge of the plywood, spaced to match your hinge cutouts.
Cover the plywood with the plastic; it is there so the aluminum can slide without scratching. Tape the pipe to the leading edge, loosely bolt the pipe to the table with the J-bolts, and twist as you please. The control surface will slide toward you as the roll is formed. It can't lift and bend a crease along the spar edge, the problem with hand bending.