Brief Description: Cut out the inspection plate hole.
I used the cheap Harbor Freaight Fly Cutter. This is a piece of crap. I couldn't use the center drill because it was not even close to being straight. And, I didn't use the opposite cutter because it was a different height from the other cutter. But I'm not sure a quality one whould have done better but maybe. Never did get it to go all the way through the rib. Ended up just drilling a small hole in the center and using tin snips to cut it out as best I could. Then used a course drum sander on high speed to finish out the size. Look at the plans closely. They show, in 2 places, that the hole is 1/2" smaller in diameter then the cover plate reinforcement ring. The plans don't tell you the size of hole and I see builder logs making the hole the same size as the reinforcement plate. I compromized and split the difference. I used the die grinder with a scotch bright wheel to finnish it off.