Here a few weeks back was doing allot of sheet metal work in the cab of my project and found the need for a small sheet metal brake, over the years I have had several but found they took up too much room so sold them off, really miss a Pexto Box and pan brake I use to own.
The need was so grate I decided to quickly build one from some scrap metal, first welded some small Angle iron to a piece of flat bar then tacked it to one of the metal saw horses I use. Then welded some heavy wall tube to each end of a piece of "T" bar, also added a piece of Flat iron to the back side of the "T" bar to stiffen it. Then welded two pieces of All thread on each side of the lower angle so that the two pieces of tube will slip freely over them.
Added two small springs in between the top piece and the saw horse, they will "Open" the brake when the nuts on top of the top piece are loosened.
Made a couple of teat bends and found I had to grid a small radius on the top "T" bar to prevent creasing the material to be bent.
It worked pretty well after making a few adjustments.