Transfer your perpendicular lines down the shell, and mark the butt mounting holes. In this case we are mounting it 2 inches from the bottom bearing edge.
Use the same methods described above to mark you air grommets and badge holes.
Drilling
To drill, you can use a trusty hand drill or a drill press. If you use a drill press, make a drilling platform that will sit on the table. The shell should sit right on the platform and be supported directly underneath where you will be drilling holes. You can make it so the drill press table will be inside the shell when the shell rests on the platform (better for benchtop drill presses), or so
the entire platform and shell are on the table.
To prevent the wood from "busting out" on the inside of the shell, use a backing piece of wood. If you make a drill press platform, you can make the platform from a good sturdy wood like maple, then use the platform for a backing piece. If you set up the platform each time so the drill bit will be drilling directly into the hole in the platform, you'll have a ready made backing piece at all times. If you
use a 1/4" drill for the lugs, and a 5/32" drill for the strainer and butt hardware, have a different hole for each setup. Of course, you'll need to rig the platform so you can clamp it to the table.
Make sure your drill bits are sharp! It is helpful to use a good brad point bit, especially if you are using a hand drill. A #1 Unibit is also used by a lot of drum makers with very good results. Don't be afraid to use a drill bit that is a bit larger than 1/4" for lugs (like 17/64" or 9/32"). In fact, we recommend using a larger bit for solid shells, segment, and stave drums. These shells will expand and
contract more than ply shells. If the shell expands or contracts, it will make the lug fit very tight and choke the drum. This we know from experience!