Tamper-resistant postage meter

A postage meter has a locking cam follower so that locking arms on the print wheels of the postage meter are able to lock the wheels from unintended movement when the print rotor is out of its home position. Stiff runners are provided below guide rods of setting racks in the rotor so that the racks cannot be displaced away from the value wheels. A sensor is placed on the rotor cover with the meter software set up to keep a print cycle from starting if the cover is open. A cam on the rotor makes it impossible to open the cover when the rotor is out of the home position. A latch holds the cover shut, and the only way the latch can be released is if the meter software releases it, for example by sliding a rack to a position that triggers the latch. Cogs and cog teeth are used instead of gears and gear teeth to reduce the possibility of unintended movement of the value wheels. Rotating disks lock the racks when the rotor is not in the home position.