Machining a Custom Launch Controller Enclosure

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Earlier in this article, I lamented using a metal case for the launch controller because it might pose an electrocution hazard if a wire came loose, and it limited the selection of panel mount components to those that are electrically insulated. That being said, anodized aluminum is attractive and rugged.

The case was purchased from the seller “abakuscom” under the auction title “Aluminum Project Box - New non ABS case electronic DIY”. The box sells for approximately $20 with shipping from Hong Kong. It’s an excellent high-quality enclosure, but I’d prefer to find a closer source for a slightly lower price. (Update: I see the same box in black for $17.50 from the seller “fan_computer” in Nutting Lake, Massachusetts.)

The first thing you want to do is measure the project box (6″ × 4.1″ × 2.2″) and layout all of the switches. I prefer to use a drawing program to calculate all of the coordinates before beginning machining.

Launch Controller CAD layout

Launch Controller CAD layout.

With the printout in hand, I mount the enclosure lid into the mill/drill machine flush against the back jaw and side plate which are considered coordinates 0, 0. Using the digital readout on the machine, I drill a small pilot hole (about 1/8 inch) in each location where a switch will be mounted.

Drill smaller holes and then enlarge by drilling bigger holes

Drill smaller holes and then enlarge by drilling bigger holes.

If you don’t have a digital readout, then you'll want to finish drilling each hole to the finished size before moving the next hole. Otherwise, if you move away, it will be impossible to realign the larger drill size over the pilot hole.

In either case, because switches tend to need fairly large holes (11.5 mm to 20 mm in this case), you need to enlarge them by stepping up a couple of drill sizes at a time. It is too strenuous on the drill machine to drill a large hole in one pass. You'll end up breaking something.

Finally, finish drilling the largest holes

Finally, finish drilling the largest holes.

In the photograph above, notice that the lid rests on two metal parallel bars so that the tip of the drill won’t cut into the vise when it is plunged downward.

The power switch for the launch controller has a little notch on one side. At first, I was annoyed that I had to perform an extra machining step with a 2 mm end mill to make a notch. But, it turns out that the power switch is the only switch that doesn’t accidentally rotate when you try to use it. Frankly, I now wish all of the switches had a notch to keep them in the correct orientation.

Milling notch in larger hole

Milling notch in larger hole.

Drilling holes for the buzzer and banana jacks was a little more difficult. I had to stuff wood blocks and bits of plastic sheet scrap underneath it to prevent the lip from flexing.

Scrap braces while drilling sides

Scrap braces while drilling sides.

The anodized aluminum enclosure machined well.

However, on my first attempt, I drilled a couple of holes too large and was forced to switch to a second (spare) box. Only after machining it did I realize that each box has a slightly different length -- so the holes are shifted to the left of where I intended them. I guess the front and back lids are cut arbitrarily from a long extruded piece.

Let that be a lesson to you: Don’t assume that eBay or surplus project boxes are the specified length or are even consistent with each other.

One other note, although I don’t notice any scratches, you might want to place masking tape or brass foil where the vise jaws contact the enclosure. This will prevent marring from exposing the plain aluminum underneath the anodized egg blue.

Finally, let’s see if all of this hard work paid off...