|
1.
Thoroughly clean both the ring gage and the setting plug in a good
cleaning solution and jet blow dry (or clean ultrasonically). Then visually
inspect to make sure all foreign material in the thread has been removed and
no nicks or burrs are present.
2.
Lubricate the setting plug with a thin film of light viscosity oil
before inserting into the ring gage.
3.
Turn the locking screw counter-clockwise until it is loosened.
4.
Turn the adjusting screw clockwise, which opens the ring to a
larger pitch diameter than the setting plug.
5.
Turn the ring gage onto the setting plug all the way to the back
(full form section) so that approximately one thread extends beyond the last
thread of the setting plug. (This promotes more uniform wear over the
entire thread length of the plug.)
6.
Turn the adjusting screw counter-clockwise until there is a
slight drag between the ring and the setting plug.
7.
Turn the locking screw clockwise until tight. This locks the
adjusting screw so that the size of the ring gage remains fixed. There
should now be a noticeable drag between ring and setting plug. Operations 6
and 7 may have to be repeated more than once to obtain the proper drag fit.
8.
Turn the ring gage from the full form section onto the truncated
section at the front. The drag should be approximately the same to both
sections, which insures good flank angle contact.
9.
Remove the setting plug from the ring.
10.
Now turn the ring onto the setting plug 1-1/2 to 2 threads at the
front. There should be some resistance or drag even at this short
engagement. To test for taper or bellmouth, place the ring on its face on
the workbench and test for shake or looseness with the setting plug. Being
very careful not to damage these end threads.
11.
Remembering the feel at the 1-1/2 to 2 thread engagement, turn the
ring further onto the truncated section. The drag should remain
approximately the same although it may be slightly greater at full
engagement due to more flank contact.
12.
Remove the ring from the setting plug and repeat operation 10 and 11
on the other side of the ring gage.
13.
The fit should be approximately the same on both sides of the ring to
insure proper straightness. Remember if the setting plug is made or worn
smaller at the front, it will falsely indicate taper or bellmouth in the
ring gage. Setting plugs must be responsibly straight.
14.
The minor diameter of a thread ring gage is normally checked with GO
and NO-GO plain plug gages. These should be made to the minimum and maximum
limits of the minor diameter of the ring gage, and to class x or xx
cylindrical gage tolerance. The GO should enter through the ring and the
NO-GO should not enter to assure that the minor diameter is correct after
the ring is set to the proper pitch diameter.
15.
It is then the standard practice to cover the adjusting screw and
locking screw holes with sealing wax. This helps to prevent unauthorized
tampering with the setting of the ring gage.
|
