but with the Uni-bit, I have to drill once and flip, hoping to match.
With a Drill Press, properly set up centerline, I drill two perfectly aligned 1/2" holes.
Sharp bit, slow feed rate - perfect holes for 12mm pixels.
This is really best done with two people. A friend and I drilled 6 tubes for 40 pixels per tube (480 total holes) in just over 2 hours. That included setup, cleanup and getting all the cuttings out of the tubes.