An apparatus comprising a cantilever having a distal end and a proximate end, a frame portion coupled to the distal end, a base portion coupled to the proximate end, and a locking apparatus coupled to the frame portion, the base portion, or the cantilever, wherein the locking apparatus has a locked position and an unlocked position, and wherein the locking apparatus prevents the frame portion from tilting relative to the base portion when the locking apparatus is in the locked position.