Various embodiments described herein may include a turret including a rotatable drive device having a length arranged along an axis that is 1) non-coincident with an axis of rotation of a spindle or a knob, the non-coincident axis 2) spaced apart from the axis of rotation; the rotatable drive device rotatable from a first position to a second position, and arranged to: in the first position, cause the spindle and the knob to rotate together as a unit, and in the second position, disengage the knob from the spindle to allow the knob to rotate relative to the spindle. In various embodiments, the knob or other second rotatable part exposes the rear end of the rotatable drive device or a lever or other user interface coupled to the rear end. Other embodiments may be disclosed and/or claimed.