This is done through the fast and loose pulleys at the headstock end of lathe.
When the nuts on these bolts are tightened, the headstock is firmly clamped to the bed.
The cam c to be cut is bolted on to the face of the worm-wheel, which faces the headstock of the lathe.
Many lathes also have gears in the headstock for changing the speeds.
This movement is repeated until the thread is cut to the proper depth, as determined by one of the stops for the headstock.
This particular machine is driven by a motor at the rear of the headstock, connection being made with the spindle through gearing.
Yet arbitrary preference for classification in the headstock subclass may bep.
Unfortunately, the gearing which once existed to connect the headstock spindle with the lead screw has long been lost.
The necessary speed changes are obtained both by varying the speed of the motor and by shifting gears in the headstock.
At the headstock end, this rock-shaft carries another segmental pinion meshing with rack teeth formed on the cross-slide.