I've spent my last few evenings marking and drilling the aluminum panel.
Tools: Caliper and rule for measuring, square and scribe for marking, center punch and hammer for making center divots for each hole.
Once marked, it's time to drill...
 |
| Center Dill #4; Stepped Unibit; Large Unibit, Carbide tipped Hole Saw |
All holes (nearly 100 of them), regardless of size, are started small and are opened larger with progressively larger bits. All are started with a Center Drill. I have a #2 and a #4. For small holes or ones which need very precise placement, I use the #2. The #4 is great for #4 screws, venting holes, etc. Larger holes then get the small Unibit. Stepped Unibits are an amazing time saver. There's no need to swap out bits in the chuck, just keep going deeper until the step is the right diameter. If you just graze the hole with the next biggest step, it even deburrs the hole. For the tube socket and output transformer holes, I use a 35mm Carbide tipped Hole Saw. It takes a lot of torque to cut a hole that size. My drillpress really bogged down, but with a bit-o-lube and unclogging the cutters every 100 turns or so, I could create a nice hole in about 10 minutes.
Now for the irregular hole needed for the AC power connector:
 |
| Marking with template; Corners Drilled; More holes; Final hole after filing |
Then a final scrub with steel wool and a green pot scrubber.
 |
| Final Panel |
