Making the Chassis
We settled on a super-sized Hammond brand aluminum chassis (12" x 8" x 2") so that the builder has plenty of room to move around in. Aluminum is the metal of choice for this project because it's in the easy-metal-to-work-with family of metals.
You can drill all the holes with a regular electric hand drill but a drill press is preferred and makes things a whole lot easier. You're going to need a 3/8" drill bit, 1/8" drill bit, a drill bit for the pilot light you choose and something like a hole punch or step drill for the 1" tube socket hole.
Before you start drilling double-check the parts list and make sure you have everything sitting right there in front of you. Do not start until you've ordered and received all your parts. You want to check them out, see how they look, get familiar with them.
We like to lay out the parts on top of the chassis before we do anything. In this way we can kinda visualize the relationship between parts and see how everything works before we start drilling. Use some masking tape and tape the parts in place according to the layout plan. You don't have to get too fussy about this, you just want to see how things are going to look.
Remember, though, all the parts are going on the inside of the chassis. This masking tape exercise is purely academic and for your sole enjoyment.
Grab a ruler, a marking pen and your layout plan. Put a dot, an X or whatever at each spot on the chassis where you are going to drill a hole. You can even write the size it's going to be right next to it. You can always make a small hole bigger but never the other way around.
Take your time, mark your holes and prepare the drill.
The hardest hole to deal with is going to be the 1" hole for the tube socket. We use a punch. The simplicity of the punch is that you drill a 3/8" guide hole, insert the punch, and tighten it up with a wrench and viola, a perfect 1" hole. If you don't have a punch, though, you're going to have to use a step drill; if you don't have a step drill you're gonna have to bug a neighbor or your grandpa or someone.
Get that hole drilled and get it drilled nice.
After you get that tube socket hole drilled, drop your socket in, center it, then mark where your 1/8" holes are gonna go.
Perfection.
Now that all the holes are drilled and punched, you've gotta do some housekeeping work. Use a deburring tool, razor knife or sandpaper. You want to ensure there's no loose and potentially dangerous chips of metal sticking up around your new holes. Smooth it all out, make the area around each hole nice and shiney.
You are ready to install your mechanical parts.