IBM Selectric - Page 159

10.2 .002" - . 005" clearance between the -5 latch and
its stop. (Shou Id reset at same time as positive lat-
ches) .
10.3 Half cycle a zero rotate character and adjust the
rotate link so that the pointer on the rotate arm
matches
the # 1 scribe on the Hooverometer, when the
Hooverometer is depressed against the damper spring.
10.4 Match the home detenting with:
a. The negative 5 latch se lected .
b. All positive latches selected.
10.5 The detents should seat fully with no side play.
10.6 2lbs. with a -5 character half-cycled.
10.7 Adjust the Rotate Arm Eccentric so that a half-cycled
-5 selection matches a half-cyc led home selection.
10.8 Adjust the print shaft timing so that the detent enters
and leaves all rotate positions without rubbing on the
skirt.
10.9 The Damper Spring must not bind on the Paper Bail
Stud. Adjust the Damper Spring Stop 1/8" - 1/16"
from bottom of the spring. A -5 selection should ful-
ly compress the Damper Spring.
10.10 COMPENSATOR WEDGE
Overcompensation may occur whenever (a) the system
receives a sudden shock which unloads the rotate arm,
(b) the detent enters the wrong typehead notch pri or
to rotate completion, (c) the detent enters the wrong
notch after rotate completion. If the wedge drops too
far (overcompensateds) check:
a. Excessive head play.
b. Shift timing adjustments.
c. Fine timing and skirt clearance #10.8.
d. Binding or sticking rotate spring.
e. Bi ndi ng rotate eccentri c arm shou Ider .
f. Bi ndi ng or sti cki ng damper spri ng # 10 . <I.
g. Popping selector latches due to maladjusted
latch-links.
h. Fi Iter shaft timing.
i •. Binding typehead due to the ti It ring spacer being
off-center.
j . Rotate spri ng tens i on # 10 .6 .
If the wedge does not drop far enough (undercompen-
sates) check:
a. Wedge is dirty, oi Iy, or serrated. The wedge
should be cleaned with IBM cleaning fluid. If
the wedge becomes scored or serrated it may be
reversed.
b. Rotate arm eccentri c adj ustment # 10.7.
10. 11 Selection System Check (See Section 13.0).
10.12 Print Magnets (See Section 14.0).
10.13 Form t'he paddle so that home detenting matches
the -4 detenti ng .
10. 14 Adjust the Rotate Arm length so that a -3 character
5-15
detents the same as a +5 character.
10.15 S.H. MAL-SELECTION
Random mal-selection may result if the C-5 contacts
open during a print operation.
What actually happens is that a given pulse of be-
tween 30 and 40 milliseconds is placed on the print
magnets, the armature is attracted, and trips the cy-
cle clutch mechanism. At this period in time I due to
some rna Ifunction, the C-5 contact opens. This, be--
ing an interlock contact, interrupts the pulse to the
pri nt magnets. The cyc Ie clutch has been activated
and the machine wi II take a cyc Ie; however, the in-
tended character wi II not be selected: Either selec-
tion of an extra cycle or mal-selection wi II occur
since the armature has restored and has not se lected
the proper latches.
One specific instance of the C-5 contact breaker
opening during a print operation is when the C-5 con-
tacts are adjusted too far to the right. The C-5
contacts are operated by a cam follower. The follow'"
er is curved unti I it reaches a flat portion which in
turn
operates the contact operating strap. If the con-
tacts are adjusted too far to the right, they wi II con-
tact the curved portion of the cam fo 1I0wer and wi II
open erroneously.
10.16 S.H. MAL-SELECTION
Random parity and selection errors can be caused by
loose
or broken selector latch extensions. A change
has been processed to improve the riveting process
used
to attach the latches and extensi ons (see 13.4).
10.17 S.H. FREEING THE ROTATE PULLEY
An easy method of freeing the rotate pu Iley from the
lower ball socket after loosening the set screw is to
tap a screwdriver placed on the lower end of the ball
socket.
~----------~--
Figure 10.1
NOTE: Be certain to maintain the .002" to .004"
end play of the lower ball socket when the set screw
is tightened.