An actuator including a motor operable to move an output member the actuator further including a shuttle and a caming arrangement axially movable relative to each other to provide rotational indexing of the shuttle and the caming arrangement relative to each other, so that different output positions of the output member are provided. A moving indicator is overlaid in a video sequence of images. The printer model may be defined by a plurality of colorant points in colorant space and corresponding colour points in colour space. The member may, for example, form part of a generally c-shaped lid structure, with the separate mechanism moving the lid structure between a lowered and raised position. The shield includes a body portion with one radial end that is fixed to one of the radially inner or outer rings, at least one electrically conductive seal on a surface of the body portion, and a plurality of filaments extending on an opposite radial end of the body portion from the fixed radial end that contacts the other of the radially inner or outer rings. The dilution device includes a valve assembly and a container supporting a pressurized fluid.