Bulkhead holes - Despite my earlier recommendations regarding bulkhead holes (see standard drilling diameter), I failed to take my own advice. Now I have to make the holes wider using a special tool.
This hole saw has a special pilot called an Oops! Arbor. Rather than having a drill bit as the pilot, the special Oops! Arbot allows for the old hole saw to be used. Notice the thin cylinder it allowed me to cut in order to widen the hole. Honestly, I was sweating bullets when my bulkheads didn't fit. This thing really saved the day. Just remember, when drilling acrylic...GO SLOW, and don't apply too much pressure--otherwise you run the risk of cracking the acrylic.