Insert Adjustment; Changing Saw Blades; Tilting Mechanism Adjustment; Scoring Blade Alignment - Powermatic 74A Instruction Manual & Parts List

The scoring blade kerf is adjusted by increasing or
decreasing the number of shims between the two scor-
ing blade halves (the scoring blade actually consists
of two narrow blades). Each shim varies the width by
approximately .004" and will vary the width from .110"
to .192".

INSERT ADJUSTMENT

Adjust the set screws as required in the insert, Figure
13, to ensure that the insert is stable and flush with,
or slightly below, the table top.
FIGURE 13

CHANGING SAW BLADES

To change a saw blade, disconnect machine from the
power source. Remove the table insert. Place the
arbor wrench on the arbor nut and use a block of wood
wedged between the saw blade and table as shown in
Figure 14. Remove the arbor nut and collar and saw
blade. Install new blade making sure the cutting edge
of the teeth at the top face toward the front of the saw.
Slide the collar on the arbor and start the arbor nut on
the threads. Snug the arbor nut against the collar and
saw blade using the wrench while holding the saw blade
with the thumb and finger tips. Wedge a block of wood
between the saw blade and table and tighten the arbor
nut securely. Replace the table insert and reconnect
the machine to power source.
FIGURE 14
10

TILTING MECHANISM ADJUSTMENT

If binding occurs in the tilting mechanism, clean off
the sawdust and pitch accumulation and re-grease. If
binding continues, check the alignment and readust
as required to center the worm with the worm gear
segment on the trunnion. If there is excessive play,
loosen cap screws and adjust jackscrews clockwise
to raise pinion, Figure 15. A tight mesh without bind-
ing is ideal. Retighten mounting screws and check
over the 90 deg. to 45 deg. range of tilt for excessive
play or binding. Readjust if required.
FIGURE 15

SCORING BLADE ALIGNMENT

Scoring blade alignment should be done after all other
adjustments have been made.
Using the rip fence, make a cut part way into a board
with the main blade, with the scoring blade up. Turn
board over and check alignment of the scoring cut with
the main blade cut. Adjust scoring saw as necessary
to provide the same amount of scoring step on each
side of main blade cut. Approximate scoring blade
alignment is made by loosening the scoring arbor set
screw, Figure 16, and tapping arbor in the correcting
direction. Fine adjustment is made by jack screws
accessed through the window in the front of the stand.
FIGURE 16