Checking Spindle Play; Operating Controls - Powermatic 3520C Operating Instructions And Parts Manual

8.13 Checking spindle play

The spindle bearing has been set at the factory for
general turning applications. There should be no
"end play" or looseness along the spindle's axis. If
any looseness should occur, it may be rectified by
carefully tightening the bearing lock nut on the
spindle, as follows.
1. Use a screwdriver to carefully bend back any
tabs on the tabbed lock washer (N, Figure 8-12)
that interfere with the insets on the bearing lock
nut (O, Figure 8-12).
2. Place the end of a flat head screwdriver down
against one of the insets of the bearing lock nut
(O, Figure 8-12).
3. Tap the handle of screwdriver with a mallet so
that it turns the bearing lock nut (O, Figure 8-
12) tighter in a clockwise direction. Rotate
bearing lock nut only about 1/16" at a time.
Do not over-tighten the
bearing lock nut or the spindle bearings will
overheat.
Figure 8-12: correcting spindle play
4. The bearing lock nut should be tightened just
enough to remove the end play and the spindle
should still rotate very freely. Run the lathe for
a time, and check for heat from the spindle
bearings. If the bearings are running hot, the
bearing lock nut is too tight and should be
loosened slightly.
5. After the bearing lock nut (O, Figure 8-12) has
been properly adjusted, carefully bend back into
place any tabs on the tabbed lock washer (N,
Figure 8-12).

9.0 Operating controls

See Figure 9-1.
(A) Power switch: Activates power flow to inverter
and motor.
(B) Spindle on/off: Push green button to activate
spindle; red to stop.
NOTE: If there is a power outage while operating the
Lathe, the Lathe will not automatically restart once
power is restored. Cycle the on/off switch in order to
restart the machine.
(C) Spindle direction: Can be activated while
spindle is turning – spindle will automatically slow to
a stop before reversing direction.
When turning with a face plate,
make sure both set screws on the face plate are
tight (see Figure 8-8) before reversing spindle.
Failure to comply may cause face plate to spin
loose from spindle.
(D) Speed control dial: Always start Lathe at
lowest speed, with dial rotated all the way counter-
clockwise.
(E) Digital readout: Displays spindle speed or
indexing position.
(F) Indexer position: Push to reset index reference
to zero. See sect. 8-6.
(G) Spindle lock.
The control box is removable and has a magnetic
base. See inset, Figure 9-1. Pull out and place on
any metal surface of lathe.
Figure 9-1: operating controls
A.C. Inverter (mounted to rear of headstock)
The 3520C Lathe uses the latest technology in A.C.
inverter drives to provide infinitely variable spindle
speeds within the specified ranges. The inverter
controls the speed of the motor by varying the
frequency of the voltage supplied to the motor. The
inverter provides an acceleration ramp that
eliminates the shock of normal starting.
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