Hi I, too, have the same kind of Ellison machine that you're describing at my school and I only tried it once, quickly. You need to have some kind of shim in with the folder for it to work. I tried to use one of the die blocks and that made it too thick. Try to find a piece of wood (or something sturdy) that isn't as thick as one of the die cuts you use for the machine. Good luck!
Michelle