In checking for the roundness, the
cylinder was mounted on the vee
blocks then the checking was done on three different crossections until we insure the approximate
checking.In checking for the concentricity the cylinder was mounted between the dead of the bench center so the
reference axis was the axis of the bench center then a reference point was chose at the point which has the
least deflection about the axis of rotation (reference axis ) then we turn the cylinder one revolution (stop
every 45 degree) and record the deflections on the dial which is almost positive deflections else some cases
so, the tolerance zone is known, which represents the possible axes that the cylinder could turn about so
the size of the tolerance zone gives a sign to the performance of the lathing machine.Firstly, a reference point was a chose at the point which has the least deflection we consider its reading
(0.00 mm ) then the readings were taken with respect to it so, by this way the tolerance for the periphery
was determined so a possible shape for the periphery was drawn by a tolerance zone of (-0.02 mm to 0.37
mm) which should be transformed to (.00 mm to 0.39 mm) because in the roundness there is just unilateral
tolerance.so, the cylinder can turn about many axes within the tolerance zone (0.00 mm to 0.25 mm)