ret and Tools for Finishing
Flywheels--First Operation]

The web of the wheel is next finish-faced with the facing cutter held in
the holder _E_, and the taper surface on the inside of the rim is
finished by the tool _L_, at the same time. While these last operations
are performed, the work is supported by a bushing on a supporting arbor
_J_, which enters the bore of the wheel. The bore is finally reamed to
size by a reamer _F_ held in a "floating" reamer-holder. When the
reaming operation is completed, a clearance groove _N_ is cut on the
inside of the rim, using a tool _G_ held in the carriage toolpost. The
first cycle of operations on the flywheel is now completed.

The flywheel is then removed from the chuck, turned around, and held in
"soft" jaws for the second cycle of operations, the jaws fitting the
outside of the wheel rim. (Soft unhardened jaws are used to prevent
marring the finished surface of the rim.) The operations on this side
are very similar to those performed on the other side. First, the side
of the rim, the inside of the rim, the web, and hub are rough-turned,
using tools held in the carriage toolpost. The inside of the rim and the
web are then finished by a cutter held in a tool-holder at _P_, Fig. 6,
which is bolted to the face of the turret. The work is supported during
this operation by a bushing held on a supporting arbor _U_, having a
pilot which enters a bushing in the chuck. Finally, the rim and hub are
finished, by the facing cutters _R_ and _S_, the work being supported by
an arbor, as before.

[Illustration: Fig. 6. Second Cycle of Operations on Flywheel]

These operations illustrate the methods employed in automobile
factories, and other shops where large numbers of engine flywheels,
etc., must be machined.

=Finishing a Flywheel at One Setting in Turret Lathe.=--The plan view
_A_, Fig. 7, shows an arrangement of tools for finishing a flywheel
complete at one setting. The hole for the shaft has to be bored and
reamed and the hub faced on both sides. The sides and periphery of the
rim also have to be finished and all four corners of the rim rounded.
The tools for doing this work consist of boring-bars, a reamer, facing
heads on the main turret, a turret toolpost on the slide rest
(carrying, in this case, three tools) and a special supplementary wing
rest attached to the front of the carriage at the extreme left.

The casting is held by three special hardened jaws _b_ in a universal