Automatic ball turner
The automatic ball turner, or perhaps a better description would be a powered circular feed, was an accessory that was supplied as standard to some of the earlier C3 lathes. Later versions under George Adams ownership sold these parts as extras. The ball turner runs via a mechanism powered by a universal joint which was also supplied with the lathe. A keyway slot allows the rod to move and extend through the spur gear to suit the position of the cross-slide and whatever attachment is fitted. The word automatic is somewhat of a misnomer, it actually refers to the ability to automatically stop rather than it being able to turn a ball automatically. This was primarily intended for factory production work where one man could tend to a number of machines in a row, the auto stop on each lathe allowed him to move back and forth resetting the mechanisms and advancing the cut each time........... See Youtube video
The lathe set up to turn the maximum sized ball on the C3 which is 2 inches, the Pittler catalogue says the maximum is 3 1/2" but the cross- slide cannot possibly retract the tool far enough back to cut a ball anywhere near this size. An extension rod is being used on the universal joint so as to reach further along the bed than is usual.
Below: is a close up of the power mechanism for the ball turner. The worm wheel is fitted on the end of the cross-slide shaft, directly above it is a collar which can be set to trip the lever to disconnect the drive at any given point. This is the automated part of the ball turner, it cannot turn a ball unattended and it simply means one man can tend a whole row of machines and return to each one in turn to reset the trip mechanism and advance the cut a fraction.
Above: The circular feed attachment fits onto the side of the saddle casting using two large bolts, both the trip lever and activation lever can be seen here.
Left: The tool and saddle have to be set at a precise angle in order to cut a perfect sphere. This is the only operation where the tool needs packing to centre height as the cross-slide cannot be raised up and locked in place as in normal practice for turning unless spacers are used. The power to the mechanism is via a rather unusual extending universal joint, for a closer view of it see here Normally work is held near the chuck when using the ball turner or power cross-slide, here you can see an extension rod is fitted to allow work on a longer workpiece
Below : A ball can also be turned in the middle of a bar providing the tool can access it properly. Here it's shows a ball in the centre of two tapers and demonstrates some of the possibilities of fancy turning for both the B2 and C3 lathes
