pic: Sheet Metal Drivetrain

[artdutra04]

Before you commit to a particular fabrication technology, make sure what you are working on can be manufactured. Not all sheet metal shops have laser/waterjet cutters; some only have a turret/punch machine that create sheet metal parts by stamping out all the holes with punches. When designing parts for these shops, you are limited to much simpler designs (e.g. standard punch sizes or some multiplication thereof). Any complex curves or triangular lightening patterns can be fabricated, but only by nibbling the turret punch. This can make the part, but all your nibbled edges will have scalloping to them.

Get rid of the outer corves edges, and make all the outside edges straight. Then put a flange onto each of these edges. When working with sheet metal, it's all about the flanges.

You'll need to further increase the corner strength; triangular/angled corner gussets is an easy way to accomplish this.

How do you plan to join all these pieces together? Rivets are great in shear, but can only be removed by drilling out the holes. If you need something that may need to be removed, use PEM nuts. On 228, we use tons of PEM nuts (#8-32 and #10-32) to hold almost all of our sheet metal parts together, as you can use countersunk flat head screw on your outer frame perimeter to comply with the ridiculous frame perimeter rules that 1/16" high rivet heads would fail.