IBM Selectric Manual

A. REST POSITION
1/16" to 3/32"
B. RELEASED POSITION
FIGURE 22. Shift Clutch Spring Retaining
Plate Adjustment
NOTE: If sufficient ad justment cannot be obtained with
the retaining plate, the right end of the cl·,ltch spring
may be placed in another hole in the ratchet. The ad-
justment can then be refined with the plate.
3. Shift Cam Stop - Adjust the stop so that the shift clutch
ratchet has .010" to .030" rotary motion between the
shift cam stop and the shift release arm with the mech-
anism at rest (Fig. 23).
Shift Release Arm ___ _
Holding Inner Lug
Of Ratchet
• 010" to .030"
Sh i ft Cam Detented
FIGURE 23. Shift Cam Stop A(~jllstment
8
The adjustment insures that the shift cam will not be al-
lowed to travel past the detented position.
NOTE: The stop should not bind against the spring
clutch when the adiustment is rr:c:de.
CAUTION: Be sure the cam is detented at the time the
stop adjustment is checked.
4. Shift Cam Brake - The shift cam brake should be adjusted
to have .035" to .040" bite on the braking rib of the
cam (Fig .. 24). That is approximately 1/2 the thickness
of the rib.
5.
.035" to .040"
1/2 Thickness Of
FIGURE 24. Shift Cam Brake Adjustrnent
Excessive braking action could prevent the cam from
reaching the detented position in the lower case. Insuf-
ficient braking action would result in a noisy shift oper-
ation and expose the mechanism to possible ports break--
age.
Shift Release - Adjust the shift release link so that the
release occurs when the key It; vel' has been depressed 2/3
of the full travel. As the keylever is allowed to restore
from a fully depressed position, the shi ft should again
operate when 2/3 travel ofthe keylever has been reached.
A balance between the two releasing points insures the
proper adjustment .
NOTE: The shift bellcrank attached to the right end of
the bail shouldbesetpriorto making the link adjustment.
For proper leverage the bellcrank should operate with
same over-center travel in both directions.
6. Shift Lock - Adjust the shift lock brucket up ur down so
thattheshiftlockengages just as the shift release occurs
orslightlyafterward. The lock should never engage be-
fore the shift release occurs. Keep the lock bracket ver-
tical during the adjustment.
The shift lock must be released easi Iy by depressing either
shift keybutton.
7. Shift Interlock
a.
723 and 725 - With the shi ft interlock on the high
pointofthe cam, adjust the interlock by its adjust-
i ng screw so that the ti p j LJst bottoms between two
teeth on the shift clutch ratchet (Fig. 25a).

IBM Selectric Specifications

General

Type	Electric typewriter
Introduced	1961
Keyboard Layout	QWERTY
Carriage Return	Electric
Manufacturer	IBM
Printing Technology	Typeball (golf ball)
Power Source	AC Power
Power Supply	120V AC