that's the nice thing about a mortising machine ol son. i can make a test mortise on a scrap of lumber, and then dial in the thickness on the tenoning jig until i have a good fit. once i have everything set up, then i can go to town cutting the cheeks, and then set up the band saw and cut the small ends off, then they are ready to go. once i have the final width of the tenons, i can lay them out, and go to town on the mortising machine. that's what i told my boss one day about my setting up for the night's print run, when i bring out all of the paper and forms that i'll need, that it is just like woodworking, once you get everything set up, and all the stock you need ready, you can run like a bandit without worrying about having enough of what you need at hand.