Printer Checks And Adjustments To Meet; Optical-Reader Requirements; Specific Print Problems And Their Cure - IBM 1403 Field Engineering Maintenance Manual

Printer Checks and Adjustments to Meet
Optical-Reader Requirements
The following procedure is suggested whenever the
output of a particular
IBM
1403 Printer is to be used for
optical-reader input. Some of the steps are obvious,
and for this reason may be easily overlooked. All the
steps are mentioned because they are the factors that
have the greatest bearing on print quality.
For aid in diagnosing specific print problems refer
to Specific Print Problems and Their Cure.
Correct Font
1. Remove the ribbon and cartridge from the machine.
2.
Check the font. It must meet the requirements of
the optical-character reader being used. The
IBM
1418 Optical Character Reader currently is de-
signed for use with either the 407-1 or 407 E-1 style
(selectively, not both). An easily identifiable char-
acter is the 4, which has a definite left
m
right 45°
stroke on the left-hand segment. The
IBM
1428 has
its own style font.
Type Cleanliness
The type slug must be clean and free of loading in
the lakes of characters such as 8 or O. Check for pits or
breaks in type faces. Clean the types that are dirty or
1 __ .1_.1 ___ !LL _!1 L __ __
! _ L ! _ _ _
11 _L ____ L ___ ___
! _ _ L
.L.. _ _ _
luau~u WIUl UU
UY
!:'ll11Ullg au \':l1ala\':l~l~ agall1~l lyl'~
cleaner (see On-Cartridge Cleaning). If the type is
extremely dirty, perform Off-Cartridge Cleaning.
Chain Tension
l. Hold the cartridge with the printing side up.
2. Move the chain about two passes in the normal run-
ning direction to be sure that the chain assumes a
natural sag from the center plate.
3. The slugs in the center of the cartridge should hang
out ){l' (+ .020", - .OO<Y') to assure proper chain
tension (see Figure 26).
4. Adjust the cartridge on current machines by ioosen-
ing the jam nut and turning the idler adjusting
screw.
Cartridge Mounting
Use care when installing cartridges that are mounted
with four cap screws (standard cartridge). Move the
cartridge toward the front of the machine while tight-
ening the screws. This prevents possible change of the
hammer-to-cartridge relationship if the cartridge loos-
ens for any reason. The interchangeable cartridge is
self-aligning.
98
Excessive Oil and Ink
Wipe off all excess oil, ink, etc. from the cartridge,
T -casting, and ribbon shield.
Observe the quantity of oil imparted to the ribbon
from the chain-lubrication system. A nominal amount
of oil does not greatly affect the print quality. Exces-
sive amounts, however, cause a definite problem be-
cause of the growth in stroke width and fuzzy edges
of the printed characters. If excessive oil is present in
the ribbon or around the print area in general, observe
the following:
l. Remove the obsolete lubricator for the chain motor
when the bevel-gear drive is installed.
2. Use care when filling the chain reservoir or when
oiling the ribbon-drive motor. Oil can drip because
of a pressure buildup in the motor.
3. If the chain throws an excessive amount of oil,
form the wiper (part 474083) so it just touches the
back of the chain. Refer to Chain Lubricator Ad-
justment.
Paralleling the Forms Path, Hammers, and Types
To obtain even print density across the entire line, the
forms path, hammers, and types must be parallel.
Check and align as directed in Aligning Hammers to
Paper Path, Horizontal T-Casting Positioning (Chain
to Hammers), and Aligning the Train to the Hammers
(Horizontal T-Casting Positioning).
Ribbon Shield
Check the adjustments of the ribbon shield in accord-
ance with the section Ribbon Shield and Print-Line
Indicator Adjustment.
Timing and Density Adiustment
Adjust in accordance with the sections Print-Timing
Dial and Adjusting Individual Hammer-Magnet As-
semblies for Timing and Density.
Specific Print
Problems
and Their Cure
Density Variation
This can appear in many different ways:
l. When irregular sections or spots appear more
dense (Figure 104), look for excessive oil in the
ribbon. Refer to Excessive Oil and Ink.
2. Sometimes when changing from short-line printing
to a longer line, the characters at the beginning
and end portions of the line of print are more
dense than those at the center of the document
(Figure 105). This can be caused by the unused
(more heavily inked) portions of the ribbon.