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PM-1228VF v3 2021-05
Copyright © 2021 Quality Machine Tools, LLC
Figure 3-4
Spindle speed sensor
The speed display is unlit when the power switch is OFF (0), or
if the Emergency Stop (E-Stop) button is pressed. When pow
-
er is restored following either of those conditions, the LCD dis-
plays
0000
— motor stationary — until the RUN motor button
is pressed and the speed control knob adjusted to the desired
setting. (This is a safety measure to ensure that a previous
speed is NOT resumed automatically following what could be
an uncorrected fault condition.)
Input to the tachometer is from a sensor in the spindle cavity of
the headstock, Figure 3-4.
The display may alternate ± a few rpm when the spindle is
running at constant speed. This is to be expected, and is not
a fault condition.
CHUCKS & FACEPLATE
The spindle nose on the PM-1228VF-LB accepts D1-4
Camlock chucks, faceplates and other work holding devices.
A D1-4 chuck or faceplate is held by three threaded studs,
each with a D-shape crosscut to engage a corresponding cam
in the spindle nose, Figure 3-6. The function of the cams is
to pull the chuck backplate inward to locate its internal taper
firmly on the spindle nose.
Figure 3-6
Camlock stud
Emergency Stop button
Slap the E-Stop button with the palm of the hand to disconnect
power instantly. The button pops out when twisted clockwise
a few degrees. This restores power, but does
not activate
the
motor (see Speed display above).
Alongside each stud is a stop screw, the head of which fits
closely in a groove at the threaded end of the stud. The func-
Figure 3-5
D1-4 three-jaw chuck
TO INSTALL A CHUCK
Disconnect the 110V supply from the lathe!
Chucks and faceplates are heavy — 6 in. chucks can weigh
more than 20 lb. They will cause serious damage if allowed
to fall. Even if a chuck is light enough to be supported by one
hand, the lathe bed should be protected by a wood scrap, as
Figure 3-7.
Figure 3-7
Protect the lathe bed
Some users add packing pieces, even custom-made cradles,
to assist “straight line” installation and removal. Before install-
ing make certain that the mating surfaces of the chuck/face-
plate and spindle are
free of grit and chips
.
The cams on the spindle are turned with a square-tip wrench
similar to the chuck key (may be same tool in some cases).
Recommended procedure:
1. Turn the spindle by hand, checking that all three cam mark-
ers are at 12 o’clock, Figure 3-8.
2. While
supporting its full weight
, install the chuck with-
out tilting, then gently turn each of the cams
clockwise
—
snug, firm, but not locked tight in this first pass.
3. Check that each of the cam markers lies between 3 and
6 o’clock, between the two Vees stamped on the spindle,
Figure 3-9.
tion of the stop screw is
NOT
to clamp the stud in place, but
instead to prevent it from being unscrewed when the chuck is
not installed.
Never leave the chuck key in the
chuck, not even for a second!
