As I mentioned in my last post, I had to (or rather, wanted to) make a sheet metal bending brake for one of my latest projects. A brake is basically a tool (or jig) in which you can insert a piece of sheet metal, and then make a clean fold or bend in a straight line.
Again, I have to credit this post on Dave’s Sheet Metal Bending Brake for getting me up to speed on the best way to design a brake.
The piece of angle-iron is screwed to the worktable. The square tube is attached to the angle-iron by two small hinges, which are welded on. The tops of the bar stock, hinges and angle-iron are all in line with each other. Finally, I have a piece of wood which can be clamped down to the brake; the front face of the wood is lined up with the front face of the angle iron.
The metal is laid on the box tube and angle iron. The wood is clamped down. The fold will happen at the edge of the wood, so we mark the metal where we want the fold, and line that mark up with the edge of the wood. When you lift the handle, the metal bends with a nice sharp crease.
Here is a brief video of the brake in action making all the folds on one of the footlights.