TM 9-1290-357-15
c. Shim the vial until bubble indicates level
Assembly of Orienting Mechanism
(bubble is in center of vial) and when the line
and Housing Assembly
of sight is in a true horizontal plane with the
objectives eccentric's thinnest and thickest walls
located in appendix B.
in a horizontal plane to permit maximum adjust-
a. Install worm (11) inside housing (7).
ment. Make several checks and then seal vial in
b. Place ball socket (12) on worm (11).
place utilizing calcined gypsum.
c. Install plunger (13) in housing (7).
Note. It may be necessary to make checks again after
vial has been completely installed before sealing vial.
d. Install setscrew (8), and special screw (9)
which locks cap (10) in housing (7). Tighten
d. Install and screw in plugs (5).
screws.
e. Install setscrews (4) locking the two plugs
e. Place spring (6), plate (5) against housing
(5) in place.
(7).
f. Place the porro prisms (2) in position in-
f. Secure plate (5) to the housing (7) with
side body (3) and carefully install the springs
screws (4).
(1).
g. Install washers (3) on each end of the worm
g. Utilizing a padded stick and lens tissue pap-
(11).
er adjust the prisms for 900 positioning with
h. Place knobs (2) on their respective positions
respect to each other in order to eliminate tilt
on worm (11).
of field of view.
i. Place and aline a pin (1) in each hole of the
Note. This instruction should be carefully performed be-
knobs (2) and drive in pins.
cause if the prisms are not at 90, the field will be tilted.
h. Stake the prisms (2) and flat springs (1).
located in appendix B.
Note. When instrument is used under conditions of ex-
Install clamping screw (1), washer (5), nut
j.
trelme heat the porro prisms must not be staked with shel-
(4), tapered pin (3) removed from housing (2)
lac varnish; use rubber cement. However, optical lens
indicated in paragraph 5-15 above.
sealing compound may be used as a sealing agent under all
conditions.
k. Install the assembled orienting mechanism
housing (2) in gear (6).
5-40 Assembly of Telescope Assembly
Note. When installing components make certa1in that
they are placed in the correct locations and are in aline-
located in appendix B.
ment.
a. Install and secure eyepiece assembly (5) to
cover (4).
5-42. Assembly of the Azimuth Worm
Mechanism
b. Install setscrew (7) and tighten.
c. Apply a small amount of optical lens seal-
located in appendix B.
ing compound to the outer edges of the inner
a. Install plunger (19), spring (18) inside body
faces of cover (4).
(21). Place socket (6) or worm.
d. Install cover (4) with eyepiece assembly
b. Install and position worm (20) in the cor-
to body (6).
rect location inside body (21).
e. Install screws (1) and secure cover to the
c. Place plug (17) in position and tighten plug
body (6).
which will secure the plunger (19) and spring
(18) to the body.
f. Utilize the same instructions outlined in c
through e above when assembling the objective
d. Install setscrew (6) into the body (21)
assembly (3) to cover (2) and installing cover
alining screw with hole in body (21) and hole
with components to body (6).
in plug (17). Tighten setscrew (16).
5-8
