IBM Selectric - Page 43

This adjustment is difficult to observe at the check
ratchet. A 1/16" .to 3/32" rotation of the cycle
shaft wi II cause the print shaft gear to turn approxi-
matey one tooth. The adjustment can easily be
read by one of the following methods.
(a) Print Shaft
Gear Method
1. Hand cycle a zero tilt, negative-five char-
acter until the cycle clutch begins to slip.
2. Pencil mark the print shaft bearing in line with
a tooth on the
gear.
3. Release the cycle clutch again by depressing
a
keybutton.
4. Slowly hand cycle the machine until the check
pawl just drops into a tooth on the check rat-
.chet. The print shaft gear should have rotated
1/2 to one tooth. If the print shaft gearrotat-
ed further than one tooth the collar must be
moved
top toward the rear. Less than 1/2 to
one tooth, move it top toward the front.
A zero ti It, negative-five rotclte character is used
~ecause it offers the greatest resistance to the cycle
shaft during the restoring portion of a cycle, caus-
ing the cycle clutch spring to slip at the earliest
possible time.
NOTE: If the collar should become completely
loose, a good starting point may be obtained by
positioning
the collar so that its adjusting screw
head is approximately in line with the high point
of the negative-five cam.
CAUTION: The cycle clutch stop attached to the
collar may prevent the shaft from reaching the
latched position. Any change in the cycle clutch
collar adjustme·nt will necessitate a readjustment
of the stop; therefore it is usuall y best to loosen
the stop before attempting to adjust the collar.
(b) Degree Wheel Method - With the machine at
zero degrees (cycle clutch latched at rest) se-
lect a -5 rotate, 0 tilt character and hand cy-
cle the ,machine slowly. The cycle clutch
spring should slip and stop driving at 170 to
175 degrees.
3.1 Cycle Clutch Spring and Collar Adjustment {Late Style
Clutch (Fig. 90.1)-
a. The cycle clutch spring and collar shall be posi-
tioned I'aterally to the left so that the longest
spring
ear is against the minus 5 cam. The parts
are so designed that the clearance between the
cycle clutch sleeve and the pulley will be .006
11
to .020
11
•
b. Radial po'sition of the collar - (The position of the
collar directly controls the radial position of the
left hand end of the cycle clutch spring with re-
~~"!ct to the cycle shaft. It det'ermines how much
the spring
clutch wi II be expanded when the cycle
clutch sleeve is latched and the cycle shaft is in
its rest
position.) Adjust the collar so that when
2-25
a zero tilt, negative-five rotate character is hand
cycled the cycle clutch spring will begin to slip
(expand) when the cycle shaft is 1/16
11
to 3/32"
from its rest position measured on the surface of
check ratchet (Fig. 90. 1).
1/16
11
to 3/32
11
Sleeve
Note: The Positive Cams Are
Almost Horizontal When The
Cycle Clutch Is Latched.
FIGURE 90.1. Radial Position of Cycle Clutch Collar
Nylon Stop Adjustment
Cycle Shaft Must Be Detente
When Setting The .007" To
.015" Overthrow
.007
11
to .015
11
Pulley
FIGURE 91. Cycle Clutch Overthrow Stop, late Style