In one version there is provided a shaft locking assembly for use in an apparatus, to provide motion control and unwanted movement elimination of the apparatus. The shaft locking assembly includes a locking device with a locking shaft having a castellated ring element with castellations. The shaft locking assembly includes a drive shaft and a rotating element disposed around the drive shaft. The shaft locking assembly includes a retaining structure assembly having a side portion with projection members corresponding to the castellations. The shaft locking assembly is in a locked position when the castellations are engaged and interlocked with the projection members, and the shaft locking assembly is in an unlocked position when a shaft engagement device is engaged with the drive shaft and the locking shaft, and actuates the locking shaft, so that the castellations are disengaged and unlocked from the projection members, and rotates the drive shaft.