TM 9-3419-234-14&P
the cone ring cover and cone ring assembly by one
1-3 ADJUSTMENTS
increment until the proper tension is obtained.
a. Headstock
(5) If proper tension cannot be gamed through
(1) Internal adjustments will seldom be necessary,
adjustment, the sectionalized driving plate is excessively
however, if required, the repair should be made by a
worn and will require adjustment. The driving plate can
mechanic skilled In making such an adjustment.
be exposed for replacement by removing the cam
(2) Excessive spindle end play may be eliminated by
bushing and unscrewing the cone ring, cone ring cover
tightening the spindle bearing lock nut, #79, Figure 13,
and floating plate from the hub and back plate.
Page 15.
(6) After adjusting the driving plate or replacing it,
(3) First, loosen the spindle bearing lock nut lockscrew.
additional adjustment to the clutch for tension will be
Rotate the lock nut clockwise until all end play is
required.
eliminated, then tighten the lock screw. Before placing
the machine in operation after such an adjustment is
c. Leadscrew
made, make certain the spindle revolves freely.
(1)
In many applications, Leadscrew Threading are
CAUTION. An over adjustment could result in
used to thread workpieces requiring relatively short thread
damage to the machine.
lengths. After an extended period of operation, the
leadscrew used to control the carriage movement in
b. Clutch
producing these threads may wear sufficiently to cause
(1) After extended service, the function type dutch,
lead error.
Figure 4, may need adjustment to restore the original
(2)
For this reason, the leadscrews on all machines
operating efficiency.
were designed to allow them to be reversed or turned end
for end. The section of the leadscrew which received little
usage can be repositioned to control the movement of the
carnage and restore lead accuracy.
(3) When threads are being produced in lengths which
require the use of the entire leadscrew, the purchase of a
new leadscrew Is highly recommended if close tolerances
are to be maintained without difficulty.
(4) To reverse the leadscrew, it is necessary to remove
the entire leadscrew assembly from the machine. This
can be accomplished by removing the lower leadscrew
change gear and the bearing thrust plate. The lead-
Figure 4
(2) To determine the proper clutch tension, shut off the
power and engage the clutch several times. When
correctly tensioned, there will be a definite snap to the
clutch lever when engagement is made.
(3) To increase clutch tension, release the clutch, pull
the spring loaded adjusting lock pin outward and revolve
the cone ring cover and cone ring assembly in a
clockwise direction, Figure 4. A series of adjustment
Figure 5
holes are provided around the outer face of the tension
plate.
For best results, revolve the assembly in
increments of one space at a time.
(4) After adjusting the cone ring cover and cone ring
assembly by one increment, re-engage the adjusting lock
pin with the floating plate. Engage the clutch and check
for proper tension by operating the machine under power.
No slipping should occur. If required, continue to adjust
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