Marked up the fore and aft faces of the CS Spar for the Wing attach holes. Tried to drill a 2.5mm pilot pilot hole which was a crap idea. Broke the bit in the second hole, about half way through the hardpoints, flush with the surface. The bit that did work was using a small plastic mirror over the hole to check vertical. Makes it real easy, thanks for the tip Drew Chaplin! Drilled the rest out to 5mm, (as close as I get to a #10 drill). Drilled the aft face out to 1/4" and hot glued 1/4" washers over the holes to help locate the drill.
Did some messages, picking up a 5mm diamond tipped holesaw and drilled out the broken bit, breaking the holesaw AND the frikken mirror whilst doing so. (Sigh). Drilled the rest of the hole out to 5mm.
Drilled the hardpoints out to 1/4" using my long bit in a cordless drill. Method that seemed to work was to rig the spar fwd face up, place a little torch near the hole on the inside and sight the drill bit from underneath with (another) mirror on a stick. Took it really slow, and cooled the bit regularly in cutting oil.
