IBM Selectric Maintenance Manual page 51

2.
The copy control lever should be all the way forward un-
less stated otherwise for the following adjustments.
Eccentric Retaining Plates - For maximum efficiency of
the copy control eccentrics, adjust the plate on each
side of the machine so that no front to rear play exists
be,tween the eccentrics and the retaining plates (Fig.
88). Be sure that no binds exist.
3. Platen Latches' - Adjust the platen latch eccentri cs with
the high part down so that the platen is held firmly in
position verti ca lIy and horizontally (Fig .88). The latches
shou Id latch and unlatch freely with the feed rolls released.
4. Platen Position - To properly adjust the print mechanism,
the correct position of the platen must be established
first and then the print adjustments made relative to the
platen position. This involves both a height adjustment
and a front to rear posi ti on. Because of the method used
in measuring these positions, it is necessary to consider
them together and adjust them alternately until both are
correct.
a. Platen Height - With the head of the Hooverometer
set at the #4 scribe line, the platen should just touch
the base of the handle when the head is resting on
the escapement rack (Fig. 89).
Center Line
#4 Scribe Line
FIGURE 89. Platen Height
Adjust the platen guide bracket eccentrics to obtain
this condition (Fig. 88). The high part of the ec-
centri cs shou Id be kept to the rear. It is necessary
to remove the deflector and front feed rolls when
checking 'the adjustment with the Hooverometer.
NOTE: The Hooverometer should be inserted at a
position just to the left of the escapement cord drum
when checking the right side and directly in line
with the rotate-two latch when checking the left
side. The handle of the Hooverometer must be as
nearly vertical as possible during the checks. The
base of the handle does not reach the center line of
the platen when the handle is vertical, but the dif-
ference in height has been compensated for in the
location of the scribe line.
2-28
b.
Platen Front to Rear - With the head of the Hoover-
ometer set at the #2 scribe line, the tool should just
span the distance between the platen and the print
shaft as illustrated in Fig. 90. Adjust the platen ad-
justing eccentrics to obtain this condition (Fig. 88).
FIGURE 90. Front to Rear Platen Adjustment
Check at both ends of the platen: In order to adj ust
l
the platen adjusting eccentrics it is also necessary
to loosen the front screws in the eccentric retaining
plates. (Be sure that the Hooverometer does not res\
on the print shaft keyway.)
NO TE: ' After the correct verti ca I and hori zonta I
positions of the platen are obtained with the Hoover..;
ometer, the vertical position may be refined to pro-
vide even printing between the tops and bottoms of
the characters. Check at both ends of the writi ng
line.
5. Carrier Shoe Adjustment
a. Carrier Shoe (early) - Adjust the upper carrier shoe "
eccentric mounting stud to provide .001" to .004"
vertical motion of the carrier at the rear (Fig. 91).
Check at several points along the writing line.
This amount of play insures free lateral movement
of the carri er yet restri cts the verti ca I movement to
heip prevent variation in the verticai aiignment of
the type.
NOTE: The eccentric is accessible with the 3"
screwdriver through the opening in the escapement
bracket just above the tab torque bar. The side of
the screwdriver blade should be used if possible.
CAUTION:
tsc;aDlem~ent
Rack
FIGURE 91. Carrier Shoe - Old Style