Dynamic Adjustment Of The Carriage Tape Brushes - IBM 1403 Field Engineering Maintenance Manual

Brush-Frame Assembly
Latch Lever
Figure 68. Carriage-Tape Brush Assembly Adjustments
7. Adjust the latch block to obtain .001" to .006"
clearance between the latch pawl and latch block
with the brush assembly fully depressed (Figure
68).
8. Adjust the brush-separator stop rod to ensure that
the brush tips are below the active surface of the
separator a minimum of
~2"
when the unit is
opened.
9. Align the tape-drive sprocket to obtain tracking of
the program tape with clearance between the con-
tact roll flanges and the tape edges. Position the
locating collar against the left-hand side of the
sprocket assembly.
10. Adjust the brush-separator stop plate (on the latch
shaft) for an overlap of .046" (± .015") from the
front of the brush separator to the rear of the stop
plate. When the brush unit is open and the brush
separator is held fully pivoted toward the brushes,
the end of the stop plate should be flush to .015"
below the lower edge of the brush separator. As
the unit is closed, the latch (upon contact with the
latch block) should cause the stop plate to pivot
free of the brush separator to permit latching.
11. Adjust the brush-interlock-switch actuator so that
the switch transfers before the latch pawl fully
disengages the latch block. Adjust for minimum
end shake with no binds.
12. After these adjustments have been made, adjust
the carriage-tape brushes dynamically. Caution:
Be sure the stop rod is located so that it will not
contact the raised hub of the contact roll. Blown
fuses could result.
Dynamic Adjustment
of
the
Carriage-Tape Brushes
1. Be sure that no binds exist when you manually turn
the forms-advance knob with the 6-8 knob in neutral.
2. Set up the carriage for dynamic adjustment.
a. Insert a carriage tape with a channel 1 punch
on every third line.
Note: Use a tape punched with the customer's tape
punch.
b. Remove the forms.
c. Engage the manual clutch in 6-line drive.
d. Program a space to zero (no numeric bits) before
print.
3. Set up the scope for:
a. 1 millisecond/division horizontally.
b. 10V /division vertically.
c. Sync on negative shift of stop brush at the CE
test point on the indicator panel.
4. Start the carriage by pressing the start key. Stop the
carriage by pressing the carriage-stop key.
5. Probe the negative shift of the emitter brush or
magnetic emitter at the CE test point.
6. Loosen the shaft expansion screw and rotate the
tape-drive sprocket with respect to its shaft so that
the tape-stop brush makes 1 ms (+ .25, - 0 ms) be-
fore the emitter brush makes. If the printer has
a magnetic emitter, adjust the carriage tape sprocket
so the tape brushes make 1.5 ms (+ .25, - 0 ms)
before the emitter pulse.
Note: All 12 channel-stop brushes must meet the specified
timing relationship to the emitter brush or the magnetic
emitter.
7. Tighten the shaft expansion screw.
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