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Copyright © 2020 Quality Machine Tools, LLC
PM-835S v3 2020-10
DOWNFEED RETURN SPRING TENSION
The quill should automatically retract when the manual feed le-
ver is released following a drilling operation. If it fails to retract,
the return spring may need to be re-tensioned — but first check
for other issued such as obstructions or lack of lubrication.
Fully raise the quill. Remove the feed handle, lock the quill,
then remove the two screws securing the pinion shaft index
plate, Figure 4-10. (Some pressure should be felt when the
second screw is loosened; if not, the spring may be broken, or
detached from the shaft — call Precision Matthews for guid-
ance.)
Allow the index plate to rotate to its neutral setting — spring
fully relieved. Using a pin wrench or needle-nosed pliers, ro-
tate the index plate clockwise 90
o
from neutral, then re-attach.
With the feed handle in place, check the return spring force. If
insufficient, try one or two additional 45
o
rotations.
GIB ADJUSTMENT
Gibs on the X, Y and Z axes control the fit of t
he mating dove-
tailed surfaces. They are gently-tapered lengths of steel or
cast iron held in place by opposing screws at each end. Ad-
justing them is a trial and error process that takes time and
patience. Aim for the best compromise between firmness and
reasonably free table movement. Too tight means accelerated
wear on the ways, leadscrews and feed motors, if installed.
Too free means workpiece instability, inaccuracies and chatter.
BOTH gib screw heads must be tight against
the gib ends. If you loosen one, tighten the oth-
er. Remove the way covers for access to the
back of the Y gib and bottom of the Z gib.
COLLET LOCATING SCREW
R8 devices are located in the spindle by a special set screw
that protrudes less than 3/32" beyond the inner wall of the quill.
This may or may not be locked in place by a second, outer,
set screw. If your R8 devices meet spec, but consistently bind
when inserted, the inner screw may be in too far.
For access to the set screw(s), lock the quill, then loosen the
locking set screw in Figure 4-7. With a pin wrench or needle-
nosed pliers, Figure 4-8, remove the spindle nose-piece —
LEFT HAND
thread. The collet locating screw should now be
visible below the quill, Figure 4-9. Adjust the screw depth using
a ball-end hex wrench (the screw may be too close to the quill
rim for a standard wrench).
Figure 4-8
Removing the nose-piece
Figure 4-7
Spindle nose-piece lock screw
Figure 4-9
Collet locating screw(s)
Figure 4-6
Back gear grease nipple
Figure 4-10
Quill index shaft index plate
Figure 4-11
Table (X axis) gib screw, left side
