IBM Selectric Maintenance Manual page 146

tool to check typehead alignment under power. The collar
is farther around on the cycle shaft, but clutch spring and
collar adjustments are not affected.
Operati anal Magnets
There are four adjustments for each of the two operational
magnet assemblies (Figure 5-2). The adjustments are
identical for both magnets and are as follows:
1. armature pivot free of binds,
2. de-energi zed armature-to-upper-yoke clearance,
3. cam clutch release arm unlatching clearance, and
4.
release arm overthrow stop.
Clearance
Operational Magnet
Mounti ng Bracket
Release Arm Resting on
Clutch Wheel Tooth.
FI GURE 5-2. Operational Magnet Assembly
Adjust an operational magnet assembly in the following
sequence, the first two steps with it out of the machine and
the last two steps with it installed. Be sure the residual is
firmly in place against the upper yoke.
NOTE: Steps
1
and 2 are for setti ng up the magnet assembly,
and step 3 determines its position in the machine.
1. With the armature sealed against both yokes, move the
armature pivot plate
to
provide .001"
-.003"
clearance
between the armature and the pivot plate. This
adjustment assures a closely-held but free-moving
armature pivot.
2. Set the limit stop plate to provide .025" -.035"
clearance between the upper yoke residual and the
armature in rest position.
3. With the armature held sealed, slide the magnet assembly
front or rear on the operational magnet mounting bracket
to provide .005" -.010" unlatching clearance between
the cam clutch release arm and the clutch wheel tooth.
This clearance can be measured as release arm movement
at the stop pad (Figure 5-2).
4. With the armature sealed, form the over throw-stop tab
on the operational magnet mounting bracket for. 020"
-.030" clearance to the lug on the cam clutch release
arm.
5-2
C5/6 Contact and Timing (1052-7 only)
There are four adjustments of the 1052-7 space/CR feedback
contact, C5/6 (F i gure 5-3). They are:
1. N/C contact strap rise,
2. transfer gap (break-before-make), and
3. & 4. timing.
The N/C contact support strap is not formed and serves as
the reference from which all other adjustments are made.
.002"-.005"
Rise
CR Cam Follower
For .015"-.025"
clearance here,
r·,..-----'-==----"""c-7
form bracket
here.
N/O Support Strap
FI GURE 5-3. C5/6 Contact Assembly
Adjust the C5/6 contact assembly in the following sequence.
The first two steps can be done with the assembly out of the
machine; the last two must be done with it installed.
1. Form the rest stop (up stop) on the contact bracket so
that, with the contact operating bellcrankheld against
the stop, the N/C contact strap rises .002" -.005" off
the end of its support strap.
2. With the contact operating bellcrank held against the
up stop, form the N/O contact support strap for. 080"
-.085" air gap between the transfer point and the N/O
point.
3. With the contact assembly installed, form the contact
bracket forward or back for a clearance of .015"-.025"
between the contact operati ng be
II
crank and the CR
cam follower. Overform slightly and come back to the
specified clearance.
Do not form any part of the contact operating bell crank.
Compromise space timing and CR timing by varying the
clearance in step 3.
C5/6
Space
CR
N/O Make
(degrees of cam rotation)
70 ± 10
165
i
20
(Duration is determined
by:
(1)
when the contact
transfers, and (2) how
much N/O airgap it had
NOTE: C5/6 N/C must not remake on a CR operation be-
fore the CR interlock contact transfers.
C2, C7, and CR Interlock (1052-7 only)
The table shows specified timings for the transfer contacts
used in 1052-7. Follow the appropriate adjustment procedure