Push Rod Travel Adjustment - Control Data Corporation BR8 SERIES Hardware Maintenance Manual

g. Change the volts/ di v of Channel 1 and Channel 2 to O. 02 volts/ di v. Move the trace
on the scope (Position Knob) up until the bottom of the two lobes are setting approxi-
mately on the base line (refer to Figure 6-8 B). For an acceptably aligned unit,
the voltage ratio of the smaller lobe to the larger lobe should exceed 80%.
h. If not in alignment, loosen the stepper motor clamp mounting screws to where a
gap exists between the clamp and casting (see Figure 6-9) and slowly rotate the
stepper motor to adjust the amplitude until the amplitude of both lobes is the same,
that is, the difference between the bottoms of both lobes is less than 5m V.
A - "CATEYES" PRELIMINARY HEAD AlIG.
B - "CATEYES" FINAL HEAD AUG.
----------------,
AMPLITUDE DIFFERENCE
~
,----",""
,-B~5~ )
Figure 6-8. Head AI ignment Ampl itude
i. Tighten the stepper motor clamp. Return to track 00, then seek back to track 38.
Verify that the 5mv specification is still met. If the specification is not met, read-
just the stepper motor, return to zero and seek back to track 38. Repeat the adjust-
ment until the 5mv specification is met.
j. Remove alignment diskette.
k. Perform Track 00 Switch Adjustment Paragraph 6.6. 9.
1. Perform Stop Gauge Adjustment per Paragraph 6.6.1.
m. Recheck all adjustments made in this procedure and l"epeat all steps having out-
of-tolerance indications.
6.6.4 PUSH ROD TRAVEL ADJUSTMENT
This procedure must be performed whenever chassis support (Figure 6-9) is
removed and replaced.
a. With front panel door closed, verify that a gap exists between the retaining ring
and the disk load bushing of approximately O. 030 inch (0. 762mm) (refer to Fig.
6-9). Perform steps b and c if out of adjustment.
b. Back-off the Door Interlock Switch Adjustment set screw.
c. Adjust disk load arm set screw (Figure 6-9 ) until gap is approximately
o.
030 in.
(0. 762mm), with door closed.
d. Proceed to Door Interlock Switch Adjustment (paragraph 6.6.5)
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