It is evident that operation of the motor drives the weight carriage in a desired direction along {HEAD ~ the beam} to vary {TAIL ~ the load} imposed by the machine 
to vary
It is evident that operation of the motor drives the weight carriage in a desired direction along { HEAD ~ the beam } to vary { TAIL ~ the load } imposed by the machine
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH