TM 1-1500-204-23-9
Figure 3-76. Checking Propeller Shaft Run Out
Figure 3-77. Telescoping Gauges
b.
Use. To use the gauge, the arms are
compressed, placed in the hole to be measured, and
allowed to expand. A twist of the locknut on top of the
handle locks the arms. The tool may then be withdrawn
and the distance across the arms measured. To measure
the diameter of a hole from 1/2 to 6 inches in diameter,
select the tool with the proper range and proceed as
follows:
(1)
Loosen the knurled nut at the end of the
handle.
(2)
Telescope the adjustable end of the
gauge of a size slightly smaller than the hole, and retighten
the nut.
(3)
Insert the gauge into the hole as shown
in figure 3-78.
(4)
Loosen the nut to permit the spring-
loaded adjustable end to expand to the hole diameter, and
tighten the nut. The spring-loaded feature will assure
proper contact.
NOTE
Ensure that the gauge is held with the
telescoping end at right angles to the axis of
the hole to measure the true diameter.
(5)
Remove the gauge and measure the
setting with an outside micrometer.
c.
Care. Observe the following practices for the
care and upkeep of telescope gauges:
(1)
Coat metal parts of telescope gauges
with a light film of oil to prevent rust.
(2)
Store gauges in separate containers.
(3)
Keep graduations and markings clean
and legible.
(4)
Do not drop telescope gauges. Small
nicks and scratches will result in inaccurate measurements.
3-22. Small Hole Gauges. For measuring smaller slots or
holes than the telescoping gauges will measure, small hole
gauges can be used. These gauges come in sets of four or
more and will measure distances of approximately 1/8 to
1/2 inch. They are shown in figure 3-79.
3-36
