IBM Selectric Maintenance Manual page 41

ring when the tilt ring play is removed in the restoring
direction (Fig. 64), As the tilt detent is allowed to seat
itself, the rear of the tilt ring should rise slightly. This
is a preliminary adjustment and will require refinement
after the proper ti It arm motion is obtained.
,..-----
...........
. /
"-
/ Rear Tooth "
Ti It Detent
\
\
Detent Enters Slightly _ _
~..-~~
I
I
I
/
,,/
To The Rear
_
.....
FIGURE 64.
Rough Homing
Onc,e the print shaft has been preliminari Iy timed and
the tilt ring rough homed, all of the following adjust-
ments that require half-cycling' should be done under
power so as to include all the stresses on the system.
When the tilt arm motion is adjusted properly, a half-
cycled (3-tilt) character will coarse align the same as a
half-cycled (O-tilt) character. That is, both selections
will provide the same rising action to the rear of the tilt
ring as the detent is allowed to seat in the detent notch.
If the O-tilt and 3-ti It coarse a I ign the same, the ·J-tilt
and 2-tilt selections will also coarse align the same be-
cause of the leverage designed into the system.
NOTE: The right hand tilt pu Iley rock nut may be left
loose while making the tilt arm motion adjustment, be-
cause a slight readjustment of the pulley may be neces-
sary during the tilt arm motion adjustment.
On late level machines the·tilt arm link has a horizontal
elongated mounting hole where it fastens about the
shouldered screw on the tilt arm and the tilt arm is lightly
spring loaded away from the side frame by a hairpin
spring. The ti It pulley spring is far stronger than the
hairpin spring, 'thus holding the tilt arm against the right
hand end of the elongated mounting hole in the link.
Although this modification has no definite effect on a
tilt operation, its function is to remove any slack that
may appear in the tilt tape. An example is when an
operator changes the typehead she may accidentally tilt
the head causing the tape to slacken.
4,
2-18
UPPER CASE
Tilt
Home POlIition
r;ltMogr'lllts
!
I
I I
•
I
I
I I I
I
I I
LOWER CASE
Home PO$ltlon
!
I i I
I
I I I i
Rotate_ -5
. .
-3 -2 -1
0 "
'2
'3 +4 +5
'"}
Rotate
2 Magl'\el'
R2A
1 R2
R1
'-5
-5
Cloekwi$e
I
Counterclockwise
T=Conloel Transferred E = M:lgnel Enerqhed
Note: If possible CE should note what
characters are I/O home and which are
latch home
FIGURE 65. Typehead Chart
Tilt Ring Homing - With a zero-tilt character half-cycled
and the ti It ring play removed in the negative or restoring
direction (Fig. 66) adjust the right hand tilt pulley so that
the rear of the tilt ring will rise about .005" when the de-
tent is manuall y allowed to seat in the detent notch (Fig.
67A) , Note: The rear ofthe tilt ring is nearest the
platen,
LIGHT PRESSURE
FI GURE 66, Removing Ti It Ring Play
Check the other tilt positions and then refine the homing
adjustment on the tilt selection that provides the least
amount of rise to the rear of the tilt ring.
As a further check, remove the ti It ring play in the pos-
iti ve di recti on and observe the detent entry on the for-
ward side of the detent notch (Fig. 67B) , The detent
should enter far down the forward slope of the detent
notch but not so far that it contacts the tip of the tooth.
By homing the ti It ring off center, favoring the positive
si de of the detent notch, a maximum amount of wear
potential is achieved.