I use a cordless hand drill to drill and tap aluminum all the time (as does this project). adjust the speed until you are pulling out long ribbons instead of dust. you can use a little oil, but its not necessary. the only issue is trying to stay perpendicular to the work, but usually a little deflection doesn't matter. also pay attention to 'wowing', where instead of drilling your perfect round hole the drill bit starts to bounce around a triangle or pentagon and you end up making too big a hole. its often best to start with a pilot drill and then a final pass to clean it up. also its often easier to use a centering drill to setup the holes. it provides a pocket for the drill to rest in so that it doesn't wander, and you can use the centering drill to fine-tune the hole pattern before you make it permanent.