Building the Sides

The sides were cut from aluminum channel on the miter saw. The channel is 1" wide with 1/2" legs, and is 1/8" thick. I started with three 24" pieces. Two are required - one is a spare. I picked up a $32 aluminum cutting blade for the miter saw and used it to first shave both ends of each piece square and then to cut the miters and length. I used a stop 7-9/16" from the blade measured at the fence. The first miter cut was made with the square end against the stop. That cut made a piece 8-1/16" long with a miter on one end. I flipped the piece end for end and the second cut put the miter on the other end. To do the next piece, I repeated the process with the other square end of the same 24" piece. In that way I got two sides out of each 24" piece. I used several clamps to hold the parts and the oak sacrificial fence to the miter saw's fence.

Mitered side pieces

The side frame is 8-1/16" on the outside edge of the pieces, leaving the sides 1/32" larger all around than the front and rear panels. That keeps the edge of the panels from sticking out and catching on things.

Cut the holes for the connectors

The power connector mounts in a round hole. The USB connector requires a square hole. It's not easy to hog a 1/2" sort of square hole in a 1/8" thick piece of aluminum using hand tools. I drilled 1/2" and squared it up the best I could using a diamond file.

Epoxying corner joints

I roughed up the joints, then applied a liberal amount of epoxy to the miters, and pushed the sides into the fixture. Waxed paper keeps the epoxy from bonding with the fixture. The fixture was a very flat piece of plywood with two straight boards glued at 90° angles. I used the front panel as a square.

Paint the sides

After a good cleaning and sanding, two coats of aluminum primer were followed by red on the outside and flat black on the inside. I didn't drill and tap the holes until after painting. I couldn't figure out a practical way to keep paint out of the threads.

Mark the sides for the tapped holes.

The front and rear panels were used as templates for marking the mounting holes on the sides. I used a Sharpie to mark the spot.