I needed to enlarge a previously drilled hole. Since I couldn’t use my hole saw’s pilot bit to center the hole, and I didn't have my drill press with me, I had to come up with a solution. What worked for me was to connect two hole saws together.
I dont have room in my garage shop for a permanent clamp table, so I made this folding version from a leftover sheet of plywood. thick, so it stores neatly in a narrow space. First, I crosscut the sheet