A dual-use playpen includes a hollow body, a separating member, and a frame member. The printing system comprises a printhead receiver to receive a printhead, the printhead to eject printing fluid drops from an array of printhead nozzles to a first printing fluid receiving zone. The end effectors are controlled with a cam-pin and cam-slot arrangement, with the end effectors including the cam-slot and such cam-slot having a proximal end slot bilaterally widened to permit the cam-pin additional movement therein. A three-way valve controlled by the plunger allows the working chamber to be connected either to the vacuum chamber or to atmospheric air.