TM 9-1220-238-14
4-9. Lubrication.
4-10. Cleaning.
Refer to Chapter 3, Section II, paragraph 3-3.
Refer to Chapter 3, Section IV, paragraph 3-11.
Section II. DISASSEMBLY AND ASSEMBLY
e. Remove six screws (9) and disk (10) by
4-11. General.
pressing upward against the underside of the disk
This section describes the procedures to be utilized
f. Remove spindle (11) Press the clamping lever,
in disassembly and assembly of board plotting M18 and
on bracket assembly (18) and carefully lift the frame
carrying chest which are designed for a minimum of
assembly (12) from the support assembly (26). Remove
maintenance and long service life.
three screws (13) adapter (14) and ring (15).
g. Remove two screws (16), two washers (17) and
4-12. Disassembly and Assembly of Board Plotting
bracket assembly (18) Remove pin (22)
h. Remove two screws (19), two washers (17(20))
a. Remove two screws (1) and plate (2) Remove
and roller assembly (21), from support assembly (26)
two screw (3) and vernier indicator (4)
Remove pin (23), knob (24), and screw (25) from
b. Loosen nut and thumbscrew (17, 18 fig B-2) and
support assembly (26)
remove scale assembly (5) Loosen two thumbscrews
i. Remove leg (35) and bracket (34) assembled
until they discharge from bracket (18) and remove
from support assembly (26). Remove pin (23(27)) and
bracket assembly (6)
knob (24(28)). Remove two screws (29), two washers
c. Loosen two thumbscrews until they discharge
(30) and spacer (31) Remove screw (33) from block (32)
from support assembly (26) and remove bracket
j. Assemble all items in reverse sequence
assembly (7)
k. Complete disassembly of a unit is not always
d. Loosen two thumbscrews until they become
necessary in order to make the required replacement or
disengaged from support assembly (26) and remove
repair Good judgment should be exercised to keep
bracket assembly (8)
disassembly
and
assembly
to
a
minimum
Section III. DISASSEMBLY AND ASSEMBLY OF MAJOR COMPONENTS
(4) Rotate frame assembly (12 fig B-l) with knob
4-13. Disassembly and Assembly of Scale Assembly
(24 fig B-1) until the line on disk is parallel with scale
edge.
a. Remove two screws (1), knob (2), and three
(5) Move lower connecting links (9) and scale (4)
screws (3), scale (4) and disk (5) from arm assembly (6).
back to upper right side position If scale edge and line
b. Remove two screws (7), two bearings (8) and
on disk are not parallel within 1/64 of an inch, repeat
link (9). Remove two screws (7(10)), two bearings (11),
steps (1) through (4) above until scale edge is parallel in
one end of link (9(15)) and ring (12). Remove two
both positions on the plotting disk without rotating the
screws (13) two bearings (8(14)) and opposite end of
frame the frame assembly
link (9(15)) Remove thumbscrew (16), thumbscrew (17),
(6) Remove stationary hold on upper arms.
and nut (18) Remove pin (20) from anchor (19)
(7) Move straight edge of scale (4) to fourth line
c. Assemble all items in reverse sequence of
from right Rotate the frame with the knob until line on
disassembly.
the disk is parallel with scale edge
d. Scale assembly must be adjusted when
(8) Move the straight edge of scale (4) to fourth
assembled on plotting board Refer to Chapter 3,
line on the left Adjust the eccentric bearing in the upper
paragraph 3-13e 1 through 6
connecting link as In steps (2) and (3) above until scale
e. Adjustment
of
scale
assembly
when
edge is parallel at both left and right sides without
disassembled are as follows:
moving the plotting disk Note When satisfactory
(1) Hold upper connecting links stationary.
adjustment has been obtained, staked the threaded end
(2) Utilizing two small spanner wrenches, loosen
of both screw (7 and 7(10)) in place
screws (7) or (7(10)) in eccentric bearing (11) in the
(9) If necessary, loosen the two screws holding
lower connecting link (9). Spanner wrench pin holes in
screw and bearing are 0093 in diameter.
index with the azimuth scale zero index. Tighten
(3) Rotate the eccentric bearing (11) until
screws.
approximately one half the angular space is taken up
Tighten screws (7 or 7(10)).
4-2
