IBM Selectric

+5
+4
+3
+2
+1
-1
-2 -3
-4 -5
FIGURE 72. Excessive Negative 5 latch Clearance
maladjusted. For this reasOn it is best to adjust the
negative latch as specified
in the adjustment rather
than by adjusting
it whi Ie observing the effects that
the adjustment change will produ ce at the type head •
7. Rotate Arm Vertical -With the type head removed andthe
machine hal f-cycled to an upper case zero rotate char-
acter latched home, adjust the rotate link so that the
point
at the top of the rotate arm is 15/32" from the ma-
chine sideframe. The compensator roller should be 1/16"
from the top of the slot when this adjustment is made.
The adjustment can be measured using the #1 scribe line
on the Hooverometer handle as illustrated
in Figure 73.
The scribe line measurement makes allowance for the
thi ckness of the compensator damper spring.
The adjustment sets up a vertical condition for three
points in the rotate
arm, the center of the pu Iley, the
rotate arm pivot point, and the rotate link connection.
With the rotate arm vertical at a half-cycled zero rotate
position, the leverage within the rotate
arm will be the
same for positive and negative movements of the. arm.
NOTE: The eccentric stud at the top of the rotate arm
should be turned
all the way to the left at this point to
prevent interference with subsequent adjustments.
FIGURE 73. Rotate link Adjustment Measurement
8. Preliminary Typehead Homing - Half-cycle the machine
using an upper case zero rotate (latched home)
char-
acter. Loosen the set screw in the bottom of the rotate
pulley and slip
the typehead so that the detent will enter
.010" to .020" from the center of the detent notch, on the
negative side
of the notch, when the head play is lightly
removed
in the negative direction (Fig. 74).
.015"
'- Head Play Removed
--..-- Clockwise
(Negative)
FIGURE 74. Type Head Homing
The main purpose of this preliminary homing adjustment
is
to aid the Customer Engineer in making the rest of the
coarse alignment adjustments.
It places the typehead
in approximately the
correct position so that its rotation,
for a given selection, may be easi Iy measured and used
as a tool
in making the next four adjustments. After
completing this sequence of adjustments the preliminary
homing adjustment may have
to be refined.
9. Balance Lever - With the machine in upper case loosen the
lock nut on the
balance lever and move the right hand mem-
ber
of the balance lever (Fig. 75) left or right until a half-
cycled +5/-5 (I/O home) combination detents (coarse aligns)
the same as a
half-cycled zero rotate character. The com-
bination can easily be obtained by holding the negative-5
se lect magnet armature.
Ba lance Leve ~-"""""",71ii
FIGURE 75. Balance lever Adjustment
Begin the adjustment by half-cycling a zero rotate char-
acter in the norma I manner. Check the detent entry to
see exactly how much off-center the detent enters with
the head play removed clockwise.
Next half-cycle us-
ing the cancellation method described above and check
the detent entry. If it is different from the normal zero
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