On a LENS printer, does the head move, or is it table that moves when printing?
Whilst this is not a definitive answer, if you watch the video on their website, LENS 450 Systems, it is the bed that moves in the X and Y axes - the head remains static. The bed also appears to move in the Z axis, after each layer (as there is noticeable bed wobble). 

However, the head is on an armature so it could be that which moves - it is not entirely clear.

LENS 450 System for 3D Printed Metals

Note that the MR-7 system appears to be similar to the 450, with its "3 Axis CNC Control System". However, the 850-R differs, inasmuch that it has: 


5 Axis CNC Control System
XYZ gantry + tilt-rotate table


which are not mentioned in the specifications of the 450 and MR-7, so the 850-R could well differ from the video.