[MrForbes]

We haven't had to drill any lightening holes since our rookie year....best practice is to design the robot so it's light enough.

Sometimes we use hole saws to make large holes, if we need them for functional reasons. But usually if we are using aluminum square tube, it will get brackets riveted to it, or maybe it will pivot on some bolts, or something simple like that, so it won't need holes larger than maybe 3/8" diameter. We don't even have a unibit.