You can build your own cutter with a can crusher, carpet blades, and a piece of "u" metal. first, drill 2 holes on each side of the u chanel so a screw will fit into the slots on the carpet blades. Next set the first blade in place and run the screws through the slots, placs a spacer next then anouther blade, spacer,etc. After you have all the blades in place and spaced, mount the u chanel to the top of the crusher. You will need some gum rubber on the base for the blades to cut all the wat through the tube. You can build this for around $20.00. Hope this helps.
Later,
Gary