Fig. 746.
Fig. 747.
The second strain is caused by driving the carrier from one side or end only, and is shown in [Fig. 746], where the dog receives the face-plate pressure at the point a, and the cut or resistance being on the opposite side of the work, the leverage of the driving point causes a tendency to lift the work in the direction of the arrow c. The direction of this latter strain, however, varies as the work revolves. For example, in [Fig. 747] the dog is shown in position at another point in its revolution, and the point a, where the power is applied to the carrier, is here on the same side as the tool cut; hence there is less tendency to spring the work. It becomes obvious then, that work driven in this manner will be liable to be oval, or out of round, as it is commonly termed.
Fig. 748.