For our projects we sometimes want a custom aluminum chassis. About 40 years ago I made a drawing showing how to bend aluminum into a chassis having a top and sides, with the sides having a small final bend to form a footer along the side. Here is a copy of that old document, recently excavated, that shows how to cut the aluminum blank, how to mark the bend lines and the sequence of the bends. I hope it helps someone.

Remember that each bend will have a “Bend Radius.” This is the width of metal that will inhabit the bend and one must add this radius to the total length or width of the metal being bent, or the side will be short that amount, in its length or height. For example, when bending the common 6061 product, a 1/8th radius will usually do the job. But go to this link to find a proper bending radius for nearly any situation.