The mirror mount alignment is much easier if you only make adjustment motions that do not influence another. The design of this mirror mount is unique.  All you have to do is position this mirror mount so that the input beam of light is on the  axis of the mirror. To accomplish this you only need to perform translation motions of the entire mirror mount assembly in the x,y,z  directions. Then by tilting the mirror in any of the 3 perpendicular planes about the axes you direct the beam to the desired target destination. The alignment is then completed without cross-talk. By using this mirror mount and procedure you eliminate many iterations, frustrations and the waste of time.