The driving mechanism rotates {HEAD ~ the tubular member} and electrode about the elongated axis of {TAIL ~ the tubular member} 
The driving mechanism rotates { HEAD ~ the tubular member } and electrode about the elongated axis of { TAIL ~ the tubular member }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL