TM 55-6680-234-40
of rotor assembly. Install shims as required
fully guide extension shaft through
to obtain end play of shaft of 0.0012 to 0.0020
hollow shaft of front motor assem-
inches. Secure rear motor assembly (19) to
bly. Pass leads back through large
plate (22) with screws (24) and locklwashers
hole in plate (22 of figure 7). Secure
(23).
front motor assembly on plate (4 of
k. Perform the starting test outlined in
4) and lockwashers (16 of figure
dure. on both motor assemblies. Adjust mo
(4)
Install front drag cup assembly (11
tor assemblies to start at the minimum start-
of figure 7) on shaft in front plate
ing RPM by turning screws (8 of figures 9 and
and shaft assembly. Lightly tap drag
11) in or out of return paths (10 of figures
cup to assure that it is properly
seated.
imum starting RPM with nuts (9 of figures
Install front plate and shaft assem-
(5)
starting test, check magnetization of rotor as-
bly on front motor assembly; care-
semblies ( 14 of figures 9 and 11) as outlined
fully guide extension shaft through
in f above,
jewel in front shaft. Secure compo-
nents with screws (8 of figure 7)
l. Using assembly fixture 1489447, proceed
and "C" washers (9 of figure 7).
as follows to assemble the front and rear plate
(6)
Mount rear motor assembly on as-
and shaft assemblies and the front and rear
sembled mechanism. Secure with
motor assemblies.
screws (13 of figure 7) and "C"
(1) Remove front motor assembly from
washers (14 of figure 7).
plate (1 of figure 10) or rear plate
Press rear or engine pointer assembly
(7)
and shaft assembly. Insert rear taper
on its drive shaft so that its tip falls
of extension shaft (1 of figure 10) in-
on the zero RPM calibration mark. If
to hole in rear shaft (7 of figure 10)
necessary use a three-flute, three-de-
of rear plate and shaft assembly.
gree hand-taper reamer to ream hub
Rear taper of extension shaft is lo-
of pointer for proper fit on shaft,
cated on end of shaft having large
Press front or rotor pointer assembly
(8)
diameter. Lightly tap shaft to assure
on inner shaft. If necessary use a
that it is properly seated.
three-flute, three-degree hand-taper
(2) Install rear drag cup assembly (18
reamer to ream hub for proper fit
of figure 7) on rear shaft of rear
on shaft.
p l a t e and shaft assembly. (Rear
Engine pointer must be able to trav-
(9)
drag cup assembly has a smaller hole
el below the 0 RPM calibration mark
in its hub than front drag cup assem-
by an amount equivalent to at least
bly.) Lightly tap drag cup assembly
200 RPM on engine scale. Rotor
ssure that it is properly seated.
pointer must be capable of traveling
(3) Extension shaft (1 of figure 10)
below the 0 RPM calibration mark
must be exactly aligned to prevent
by an amount equivalent to at least
friction in the assembled indicator.
10 RPM on rotor scale. If necessary,
Position rear plate and shaft assem-
check adjustments of hairsprings and
bly in assembly fixture; rotate shaft
hairspring plates as outlined in g(5)
to check its alignment; if shaft does
and (6) above to obtain these con-
not run true, press on side of shaft
ditions.
with finger until exact alignment is
secured. Reinstall front motor as-
(10)
Solder leads of stator assemblies to
sembly on plate (4 of figure 10) of
terminal pins of receptacle assem-
rear plate and shaft assembly; care-
blies in accordance with figure 6,
14
