For workpieces which are not very long or have no cylindrical gripping surface, face plate mounting is convenient. A face plate is provided with many radial slots. These can be used for anchoring clamping studs and heel supports, used for plate clamps. Workpieces with eccentric bore can be machined by centralizing the bore, by suitably moving the workpiece along the face plate, and clamping it in a centralized position.
As the name implies, face plate is very convenient for facing work. In fact, there are special facing lathes which have only a face plate and tool carriage, and no tailstock.
Other miscellaneous operations possible on lathe
Ingenious turners/engineers can execute many other operations on the lathe, some of which are:
1. Milling: The tapered bore of the lathe spindle can be fitted with an end-milling cutter, by using an adaptor sleeve and a make-do draw bolt. Removing the tool-post, the carriage and the compound slide can be used as the work table. A suitable clamping arrangement or fixture is provided to position and clamp the workpiece on the carriage, for facing, slotting, milling keyway, etc. I have converted an old center lathe into a special machine
for milling sector of a drafting machine component.
Horizontal milling cutters can be mounted on a special arbour which can be held in a self-centering chuck at one end, supported by the tailstock center at the other. The carriage can be mounted with a workpiece. The compound slide is used for effecting the manual feed.
2. Slotting Keyways: The workpiece is held in chuck and [if necessary] supported by the tailstock center. The keyway tool which is shaped like a parting tool, is mounted on the tool-post. It is mounted with the cutting face facing the headstock. The tool must be centralized with respect to the workpiece, using packings.
While cutting the keyway in a shaft cross-slide is used to adjust the cut (which should not exceed 0.15 mm), cutting is carried out by moving the saddle longitudinally to execute the stroke. It is like broaching or slotting a keyway, but at a much lesser speed. The shaft keyway must be open at one end to allow longitudinal entry of the keyway tool.
For keyway in a bore, it is necessary to mount the tool in a boring bar. Inadvertent spindle and workpiece rotation, must be prevented by engaging the back gear of the lathe.