Most hardware stores offer a very good range of tools like drills. However, when you need special sizes for our special helicopter application, it is very helpful to have a drill set handy which includes exactly the right diameters.
Typical applications:
Drill 1.8 mm Ø for flange-head self-tapping screws
Drill 2.0 mm Ø for M 2.5 threads
Drill 2.5 mm Ø for M 3.0 threads
Drill 8.0 mm Ø for holes in the canopy to accept rubber grommets