Hi,
I cut using the slot in the front that unbelievably is not meant for the purpose (should have been done right to begin with IMO), and it's safe (no wires under there to worry about).
There is also a channel on the backside that works pretty well also, but that one works best for getting a straight cut off the end of a roll before you feed it.
BTW, I'm assuming Z3100 (my printer) is the same design as your Z3200.
So long for now, TOM