Tailstock Drive
Most versions of the Pittler C3 were supplied with the means to drive the leadscrew via the tailstock end of the lathe, this required power from an overhead drive to the pulley fitted on the tailstock mechanism. Although it could also be worked by hand it was best suited to run via the overhead drive. Driving the leadscrew from the tailstock end is used for spiral cutting and certain other machining operations . The power goes along the leadscrew, up through the reversing gears to the mandrel where it turns both the chuck and saddle very slowly according the worm and worm wheel used.
In the photo below left can be seen the large carriage handle on the end of the leadscrew and normally used to quickly traverse the saddle for general use, to the left of it is a large worm wheel and below it a worm. The long activation lever is used to raise the worm via an eccentric shaft to locate on the worm wheel which then locks in place. It can be automatically released by movement of the saddle against the rod underneath the bed or via the knob on the front of the casting, some versions of the C3, notably those plated by George Adams, use a hinged mechanism to lift the worm up. The automatic stop is triggered in either direction by adjustable stops on the long rod that runs beneath the lathe bed. The handle in the foreground is used to traverse the leadscrew by hand via the worm and gear. This is used as an alternative to overhead drive power to the pulley at the rear of the same shaft, however it requires very many turns to move the saddle just a fraction so rarely used this way.