Originally Posted by C586
Something easier to use and wont ruin the hole saw is iron pipe and some washers. Use a screw on clean out with a hole drilled in it and same idea you had with the holesaw.
I actually looked for some pipe but didn't want to cut it and had to buy a length. It was easier and quicker at the time to just buy the 5 dollar hole bit. Down on the spindle it's just really tight. Had to get the exact right sizes. The method is the same.