Been a while since I used mine, but doesn't the DadoMax have a set-up that uses a piece of the material being fitted and a couple of dowels? I'd have to go out and re-read the instructions to confirm.
Sorry, the DadoWiz (which is the one that I have) uses the dowels, here is the manual for the DadoMax showing use of the notches in the edge to set the dado width.