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