A friend at work asked me about cutting a 4"X6"X3.5" deep mortice for the second floor joists of his log home. He needs to cut about 40 of these mortices and also 4 that are 12" long for the 4X12's. We have decided that a 3.5 " hole saw to hog out the bulk of the material, a circular saw (for the long sides) and some sort of router jig for the bottom and a lot of chiseling might suffice. To me this seems like a lot of work. He has a Plunge router, 16" makita circular saw, Prazi 12" beam cutter, and hand tools at his disposal. Does anyone out there have any better ideas?