Operational Control - IBM Selectric Manual

3.
4.
1.
Cord Tension - With the cords properly threaded, adjust
the carrier return cord drum so that the inner flange of
the cord tension pulley is
3/16"
to
1/4"
from the power-
frame.
The position of the pulley insures that it will not con-
tact the cover as it compensates for the cord stretch.
Adjusting the pulley nearer the powerframe puts an un-
necessary load on the cords.
CAUTION: Be sure to remove all end play from the
escapement shaft before tightening the carrier return
cord drum. End play is removed by holding the escape-
ment shaft forward whi Ie the cord drum is moved to the
rear against the rear bearing.
NOTE: The eccentric mounting stud for the front idler
pulley should be set so that the pin is horizontal and
above center on the eccentric. The pin will then be
angled toward the left sl i ghtly.
Mainspring Tension - The mainspring tension should be
1/2
to
3/4
pounds measured at the carrier as it escapes
through the line lock loadat the extreme right hand mar-
gin. Adjust byturningthe mainspring cage. The capac-
itor(ifpresent) and the cage stop screw must
be
removed
in order to make the ad justment.
NOTE: An approximate setting cam be obtained by
making
5
full turns on the mainspring with the carrier at
the extreme right hand limit of its travel.
CAUTION: The mainspring should be handled care-
fully to prevent it from slipping when the tension is be-
ing increased or decreased.
OPERATIONAL CONTROL MECHANISM
Keylever Pawl Overlap - Adjust each keylever pawl guide
stud so that all the keylever pawls, except the index
keylever pawl, overlap their respective interposers by
.035"
to
.045"
with both parts at rest (Fig.
104).
The
index keylever pawl guide should be adjusted for
.040 11
to
.050
11 overlap. The overlap insures proper repeat/non-
repeat action.
.035 11
to
.045"
(Index Keylever Pawl
Requires
.040"
to
.060).
FIGURE 104. Keylever Pawl Overlap Adjustment
39
2.
Keylever Pawl To Interposer Clearance
a. Adjust the height of the interposers by positioning
the keylever pawl guide bracket up or down to ob-
tain a clearance of
.020"
to
.025
11
between the in-
dex keylever pawl and the index interposer at rest
(Fi g.
105).
The keylever pawl guide bracket should
be kept horizontal.
b. The adjusting slot in the carrier return keylever
should
be
formed to obtain
.020"
to
.030 11
clearance
between the keylever pawl and the interposer at rest
(Fi g.
105).
c. The ad justing slot in the backspace keylever should
be formed to obtain
.030 11
to
.040
11 clearance be-
tween the keylever pawl and the interposer at rest
(Fig.
105).
d. Adjust the spacebar lever eccentric with the high
part forward to obtain a keylever pawl to interposer
clearance of
.005 11
to
.015"
(Fig.
105).
.020"
To
.025"
For Index
Keylever Pawl
Guide Bracket
.020"
To
.030"
For Carrier Return
.030"
To
.040"
For Backspace
.005"
to
.015"
c' e arancK
For Spacebar
3.
FIGURE 105. Keylever Pawl To Interposer
Clearance Adjustment
These clearances insure proper timing of the inter-
poser release during the depression of a keylever.
Operational Latch Height - Adjust the latch adjusting
screws for the backspace and spacebaroperational latches
so that the latches wi II pass under the cam follower lever
with a clearance of
.001"
to
.015 11
(Fig.
106).
Adjusting Screw
Spacebar or Backspace
Operational Latch
Cam Follower
.00 1"
To
.015"
~
T
FIGURE 106. Latch Height