TM 9-1220-238-14
Figure 2.2 Board plotting M18 - Two-man operation
relieve pressure on the adjusting thumbscrew while
2-6. Operational Checks and Adjustments.
turning the thumbscrew).
a. Place the scale assembly on the rest bracket as
c. Check the surface of the disk assembly to be
located by either the one or two-man configuration.
certain it is not scored, nicked, scratched, stained or
Press the brake lever and, holding the lever depressed,
damaged to the extent that plotting errors could occur
rotate the frame assembly The frame assembly should
during operation. If such a condition does exist, turn the
rotate smoothly through the entire range of travel
disk over and utilize the new surface If necessary, wash
without binding. If It does not, recheck the spindle and
the plotting surface with a soft cloth and mild soap
frame assemblies for proper seating and the vernier
solution. If both sides of disk are unserviceable, replace
bracket and roller assemblies for proper mounting and
the disk assembly
function.
d. Rotate the slow motion vernier knob (fig 1-1)
b. Check to be certain that the scale assembly has
until the index screw is approximately in the center of
been properly installed (para. 2-5k). Move the plotting
the vernier bracket assembly aperture. Press the brake
scale assembly back and forth across the plotting disk
lever (fig. 1-1) and rotate the table until the zero
The plotting scale shall bear lightly upon the plotting
graduation on the azimuth scale is roughly in alinement
disk without scraping If it scrapes the disk, rotate the
with the zero graduation on the vernier. Release the
adjusting thumbscrew (fig 2-1) clockwise until the
brake lever Rotate the slow motion knob until the
plotting scale bears upon the plotting disk with optimum
indices are in perfect coincidence. Move the
pressure (Lift the scale assembly at the elbow ring to
2-4
