a. SETTING UP AND ADJUSTING THE CROSS-LEVELING FIXTURE
1 Secure cross-leveling fixture (1) on a solid stand
bolted to the floor.
2 Place precision level (2) on square shaft (3), per-
pendicular to axis of rotation, and center bubble.
3 Place precision level (2) on square shaft (3), paral-
Iel to axis of rotation, and center bubble.
Set cant vernier scale (4) and elevation vernier
4
scale (5) to "0".
5
Mount fixture adapter (6) on cross-leveling fixture
(1); center fixture adapter (6) by means of four
setscrews.
Hold M1A1 gunner's quadrant against mounting
6
surface (7) of fixture adapter (6), and establish a
level position by shimming the fixture adapter (6).
7
Place precision level (2) on surface (8), which is
parallel to fixture adapter (6) keyway, and check
that keyway is level. If necessary, shim fixture
adapter (6) to obtain a level position.
Repeat steps 6 and 7 until both surfaces are level.
8
9 Secure fixture adapter (6) with six mounting screws
(9).