Drill rear spar holes. Well, I finally did it. After much deliberation and worry I decided that it was best to just go for it. I already had the box to aim for and all it needed was a hole inside the box, can't be too hard. The next problem to solve was how to drill a perfectly straight hole. My 90 degree drill kit uses threaded drill bits so I put one of the shortest ones into a countersink cage tool. This would allow the base to lay flat against the spar ensuring a straight start. I then upped the size and length of the bits until I broke through the other side. I now had a perfectly perpendicular hole. Then it was just up the drill sizes until I got to the correct 5/16" size. The bolts fit very nicely with the head flush against the metal. What a great feeling to have these two critical holes out of the way.
