A method for controlling a printing operation includes detecting at least one position andor an extent of a register mark located on a printing material by means of a register mark sensor, and using the detected at least one position andor the extent of the register mark for register control. The mechanical movements required are as for a conventional gearbox having a H type pattern. An object containing tube is located within an outer tube, wherein the object of interest is held within or flows through the object containing tube. In a disengaged position, the first and second members are permitted to free-wheel relative to each other in a second direction opposite the first direction. The pallet is preferably precisely located and clamped in the diverter.