Sheave And Belt Alignment; Checking Spindle Play; Sheave/Drive Belt Replacement - Powermatic 3520B Operating Instructions And Parts Manual

Sheave and Belt Alignment

The motor and spindle sheaves are aligned with
each other at the factory, but if any service is
performed that affects their alignment it is very
important that they be realigned. To realign
them, loosen the two set screws on the spindle
sheave (C, Figure 25) with a hex wrench, and
slide the spindle sheave into the proper position.
Re-tighten set screws.
When sheaves and belt are properly aligned,
there should be no unusual pulsing sounds or
noise coming from the belt.

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 ever occur, it may
be rectified by carefully tightening the bearing
lock nut on the spindle, as follows. (See Figure
26).
1. Use a screwdriver to carefully bend back
any tabs on the tabbed lock washer (C,
Figure 26) that interfere with the insets (B,
Figure 26) on the spanner nut.
2. Place the end of a flat head screwdriver
down against one of the insets of the
bearing lock nut (B, Figure 26).
3. Tap the handle of the screwdriver with a
mallet so that it turns the spanner nut (A,
Figure 26) tighter in a clockwise direction.
Rotate the spanner nut only about 1/16" at a
time.
Do
spanner nut or the spindle bearings will
overheat.
4. The spanner 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 spanner nut is too tight and
should be loosened slightly.
5. After the spanner nut (B, Figure 26) has
been properly adjusted, carefully bend back
into place any tabs on the tabbed lock
washer (C, Figure 26).

Sheave/Drive Belt Replacement

Replacing the spindle sheave can be a difficult
procedure; it is recommended
headstock be taken to an authorized service
center for this.
not overtighten the
that the
Figure 26
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