{HEAD ~ The first and second grinding wheels} 56 and 76 are operably connected to, respectively, {TAIL ~ the first and second motors} 50 and 70 such that when the first or second motor 50 and 70 is operated, the first or second grinding wheel 56 and 76 rotates 
are operably connected to
{ HEAD ~ The first and second grinding wheels } 56 and 76 are operably connected to , respectively , { TAIL ~ the first and second motors } 50 and 70 such that when the first or second motor 50 and 70 is operated , the first or second grinding wheel 56 and 76 rotates
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH