A first drive unit moves {HEAD ~ the tool} along {TAIL ~ at least two axes} to shape the workpiece similar to a desired surface 
along
A first drive unit moves { HEAD ~ the tool } along { TAIL ~ at least two axes } to shape the workpiece similar to a desired surface
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH