OP-755 Part 2 Pages 197-401 - Personal Page of GENE SLOVER

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(h) Adjust micrometer couplings to bring dials to zero. Loosen
clamps on operating shafts.
(L) Check zero elevation by means of a leveled transit sighted
into the windowof the sight telescope (Mk:.66). Reset
dials as required.
2. The adjustment and alignment processes previously outlined can
be made as follows:
(a) Determination of trunnion tilt (item l(a)) for center gun.
Remove top bolt of the trunnion bearing cover plate
(216343-1) for clearance purposes. Back out remaining
bolts so that four equally thick spacer blocks maybe inserted
between the cover plate and the outer bearing seat
(216343-1). Insert blocks previously machined to a thickness
of about 5/8 inch and space sameat equal intervals.
Tighten bolts on spacer blocks. Onthe accurately finished
30.247 inches diameter, temporaily exposed suI'fl3.ceof the
cover plate bearing, place a V-block beariIlg#hich acts
as the base for a vertical bar provided wibh :me~sfor
leveling so that it can be set truly vertical. Set up and
level a transit so that there is an unobstructed' view of
both trunnions of the center gun. Sight. t:raIr~'~:t'?n the
leveled vertical bar which rests upon the c:ov6r plate
bearing. Locate. either by marking the vertt9?:lpar or
by sliding an attached pointer, the posi tioh' "h&re the
line of sight of the leveled transit cuts the bar. Move
bar to opposite trunnion of the same gun. Train transit
to sight on the bar in its new position, andaga.in mark
posi tion of line of sight. Measure di.f'f'er-encexinhe Lght.s
of marks. Compute trunnion tilt, based upon the separation
of the two positions of the bar. Adaptations of this
procedure may be worked out.
(b) Alignment of axis of telescope bearings (item l(b)). -
Mounta substantial steel tubing (approx. 2 ins.dia., 36
ins. long), truly round and of a uniform diameter, in two
truly round discs which will fit inside the sight telescope
ball bearings. This unit should be of such workmanship
that, when assembled, the rod is centered accurately
in the several discs, and is free from any eccentricity
when the discs are rested on V-blocks and the unit is rotated
360 0 • Mount discs in a pair of ball bearings of the
same type and accuracy as those carrying the telescope in
its holder. Assemble unit in telescope holder so that it
occupies the position normally taken by the sight telescope.
Mount a dial indicator on some rigid base free of
the moving sight parts, and place spindle end against the
cylindrical surface of the rod, as close as practicable
to the outboard or free end of the rod. Rotate the telescope
bracket to a position corresponding to that required