IBM Selectric Service Manual

MACHINE LOCKUP
d. Binding Operational Shaft
19.0 Machine Lockup
e. Dry or binding Shift Clutch
20.2 Motor Fails to Drive
19.1 The most common causes
of Machine Lockup'are:
~=-=-"""----::c-:~r-::--r:-::--:r:c:------:-:-:-;--:-T- _____ Ll ~-,T-LhLeermaLcut~ut-Open,-
-----cr;-Ine--cyc-le--clufCn Spring may be broken, out of 2. Dry motor bearings.
adjustment (Section 15.0), or is in need of lub-
rication.
b. Idler gear binding. Remove and lubricate with
#10 oil.
c. Remove the type element, then recheck for lock-
up. If no lockup is encountered, a II type head
motion adjustments and print shaft timing must be
checked.
d. The Print Sleeve and bearings may be dry or worn.
e. Binds in the Carrier and Rocker Assembly.
f. Check the Print Cam Follower for bi.nds.
g. Oversize Cycle Clutch Pulley and Hub Assem-
bly. (Section 15.5)
h. Shift Cam Back-Up Roller adjustment. (Section
4.8)
i. Operation Shaft binds or Shift Cam adjustment.
(Section 4.0)
j. Shift Spring Clutch is dry or requires adjustment.
(Secti on 4.0)
k. Dry center bearing. (Section 15.7).
FAI LURE TO START
20.0 Failure to Start
If motor attempts to drive, check:
20.1 Centrifugal <;:Iutch Binding (See Also 21.3)
a. I/O PRI NTER CENTRI FUGAL CLUTCH
A
sintered iron pulley with a Mylar ® insert and
nylon clutch pawls has been released to eliminate
motor clutch lockup and pu Iley wear.
The nylon pawls are used to eliminate wear on
the teeth of the bronze pu Iley .
The
sintered iron pulley has a slightly larger in-
si de diameter to accept the Mylar ® sleeve.
When replacing the motor pulley, clean the mo-
tor shaft thorough Iy to prevent future binding. A
piece of fine emery cloth may be used while run-
ning the motor. Remove any abrasive material,
using IBM cleaning fluid, prior to assembly.
NO,TE: If emery cloth is used to clean the motor
shaft, the enti re paw I assemb Iy must be removed,
as a safety hazard is present if the emery cloth
contacts the moving pawls and springs.
Lubricate the new sintered iron pulley with IBM
#10 oil during initial assembly and thereafter as
required.
A II parts necessary to convert to the new clutch
assembly are avai lable under B/M 1272045.
b. Cycle Clutch Pulley oversize.
c. Dry or binding Center Bearing (15.7).
20.3
Capacitor Start Motor
In order to eliminate problems which have existed
with the shaded pole motor and clutch, an improved
capacitor start motor is avai lable for use in instances
where repetitive fai lures have been encountered
with the previous clutch arrangement. The new cap-
acitor start motor uses a 4 mfd. capacitor whi ch pro-
vides much greater starting torque than previous cap-
acitor start motors. This new capacitor start motor
will start the I/O under any load conditions with
normal line voltages.
Parts may be ordered as follows:
Part No.
1166082
1272458
Desc
ri pti on
Motor, 115V, 60 Cycle
B/M, Motor+Mounting
NOTE: This B/M contains motor and all hardware
and a template necessary to mount t~e motor.
20.4 Worn or Broken Be It
4-26
Drive belts may be breaking on machines receiving
heavy usage, or machines over a year old. The next
time the cyc Ie shaft is removed for replacement or
adjustment, the motor belt should be replaced, re-
gardless of its age or condition. It is also recom-
mended that an extra belt be placed on the cycle
shaft .
The
be It shou Id be slipped over the cyc Ie shaft and
tied with wire or lacing cord.as illustr.ated below.
Wire Or Lacing
Figure
20.0
The motor belt should be turned inside-out so that the
smooth portion of the belt is rubbing on the cycle
shaft. It shou Id be fo Ided over as shown be low and
wrapped, and then left hanging under the cycle
shaft and slightly toward the front of the machine.
Since it will be difficult to describe exactly how to
fold and wrap the belt, you must insure that after the

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