Precision matthews PM-1440GS User manual

1Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Model PM-1440GS Lathe
High precision 3 HP gap-bed machine, with 2-axis DRO
2 inch spindle bore, with stock-centering spider
D1-5 camlock spindle mount
40 in. between centers, 14 in. swing over bed, 19-3/4 in. over gap
8 spindle speeds from 60 to 1800 rpm
Multi-speed gearbox for full-range screw cutting, TPI & mm pitch
Bidirectional power feed for saddle & cross-slide
Weight, including cast iron stand & coolant system 1800 lb
PM-1440GS standard conguration Includes 2-axis DRO, 3-jaw (reversible) & 4-jaw chucks, faceplate,
coolant system, footbrake, worklight, steadies, wedge-type QC toolpost, assembled on cast iron stand

2Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
PM-1440GS
FAQ
POWER light o󰀨, left arrow?
240 Vac power connected?
Circuit breaker in the electrical box
tripped?
E-STOP button in, right arrow?
Rotate it, should pop out.
My lathe doesn’t
run at all (1)
This manual contains essential safety advice on the proper setup, operation, maintenance, and service of
the PM-1440GS lathe. Failure to read, understand and follow the manual may result in property damage
or serious personal injury.
There are many alternative ways to install and use a lathe. As the owner of the lathe you are solely
responsible for its proper installation and safe use. Consider the material contained in this manual to
be advisory only. Quality Machine Tools, LLC cannot be held liable for injury or property damage during
installation or use, or from negligence, improper training, machine modications or misuse.
This manual describes PM-1440GS machines as shipped from November 2016. There may be detail di󰀨erences between
your specic machine and the information given here (with little or no impact on functionality). Please email us if you have
questions about any aspect of the manual or your machine (see our website www.precisionmatthews.com for support
addresses). Your feedback is welcomed!
Belt cover in place? This closes the inter-
lock switch, bottom arrow.
FOOTBRAKE working, not stuck down?
If working properly, the footbrake should
close the microswitch, top arrow, opening
it when released.
CHUCK GUARD swung back? Close the
guard (photo, cover page).
The motor didn’t run when
power was connected
My lathe doesn’t
run at all (2)
By design it should NOT run if the Motor
Control lever is UP or DOWN when
power is connected.
Electrical schematic, Section 5: Move
the Motor Control switch to neutral, mid
travel, to energize the power-switching
contactor KA, thus restoring normal
conditions.
Copyright © 2020 Quality Machine Tools, LLC
This material was originated by Precision Matthews. No portion of
the manual may be reproduced or distributed in any form without
the written approval of Quality Machine Tools, LLC.

3Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Section 1 INSTALLATION
THESE ARE THE MAIN POINTS TO WATCH OUT FOR!
But read the following pages for more information
• Handling the lathe is at least a two-man job.
• Lifting gear – sling, hoist or forklift – must be rated for at least 1-1/2 tons.
• Working location of the mill must allow space for removal of the belt cover at left; also, ac-
cess to the coolant system (back of right hand cabinet) and the electrical box at the back
of the headstock.
• Power requirement is 220V, 60Hz, 1φ, 20A circuit protection (spindle motor 12A full load).
• Extension cord not recommended; if no alternative, use 12 AWG not longer than 20 ft.
• Before connecting power be sure that:
1. The machine is on a rm footing.
2. Chuck camlocks tight, no wrench left in chuck.
3. Saddle and cross slide approx. mid-travel, power feed disengaged (Figure 1-9).
4. The headstock gear selectors are set for the lowest spindle speed.
SETTING UP THE LATHE
The PM-1440GS is shipped fully assembled in a single pack-
ing case. The machine can be lifted in one piece by an over-
head hoist or forklift with slings and/or chains, all items rated
for a total weight of at least 1-1/2 tons. To lift the machine clear
of the pallet use 1 inch diameter steel bars through the holes
in LH and RH stand cabinets, Figure 1-1.
Figure 1-1 Lifting holes
Install six 500 lb-rated leveling mounts in the mounting holes
of the two stand cabinets, 4 for the left hand cabinet, 2 for
the right. Alternatively, level the lathe using metal shims under
the cabinets. The mounts shown in Figure 1-2, available from
Precision Matthews, allow leveling adjustment from above.
To install this type of mount, remove the threaded stem from
the inverted cup stamping (yellow), then place the cup under
the stand with holes aligned — no washer between stand and
mount. If there is insu󰀩cient headroom in the stand, short-
en the threaded stem; re-install it, with washer and locknut,
through the hole in the stand. Once the stem has bottomed
in the mount, further rotation of the stem (using a wrench) ex-
pands the inner core of the mount, thus raising its upper sur-
face.
Inspect the coolant tank and pump assembly in the RH cabi-
net, Figure 1-3. The tank may have become dislodged in ship-
ment. Level it if necessary.
Figure 1-3 Coolant tank
Figure 1-2 Top-adjusting leveling mount (optional)

4Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
POWER CONNECTION
As shipped. the PM-1440GS is set for 220 V. If your supply is
nominally 240 V, it may be desirable to alter connections to the
24V transformer in the electrical box.
Read Initial Checks, next page, before connecting power
If the lathe did not come with a pre-installed power cord, con-
nect to the power source using 12 AWG (minimum) 3-wire cord
through a strain relief bushing sized for the electrical box ports.
Depending on installed options and other factors, the entry
point shown in Figure 1-6 may not be available. Connect the
ground wire (PE) to the grounding plate at bottom left. Connect
L1, L2 to the left-most two terminals on the bottom terminal
strip (the wires may be marked L, N instead of L1, L2).
Figure 1-5 Slide-out chip tray
Figure 1-4 Footbrake & belt cover interlocks
Brake OFF,
switch closed
Belt cover
switch
Foot treadle
operated,
(brake ON),
switch open
LEVELING
Make sure the lathe is in its permanent location. The following
procedure ensures that the lathe bed is in the same state as it
was when the lathe was checked for accuracy in manufacture
— level from end to end along the bed, and from front to back.
In other words, no warping.
Make sure all leveling mounts and/or shims are properly
weight bearing, rmly in contact with the oor. Check and ad-
just level from end to end using a precision machinist’s level, if
available. If not, use the most reliable level on hand. Check and
adjust level front-to-back across the bed using a matched pair
of spacer blocks to clear the Vee tenons on the bed ways. The
blocks need to be at least 1/4 inch thick, ground or otherwise
accurately dimensioned. Alternatively, check for level on the
ground surface of the cross slide as the carriage is traversed
from end to end. See also "Aligning the Lathe" in Section 4.
FOOTBRAKE & BELT COVER INTERLOCKS
The lathe will not run if the belt cover is removed, allowing the
interlock switch to open, Figure 1-4. The same applies if the
footbrake switch fails to close when the foot treadle is released
(brake OFF). Both switches should be checked before power
is connected.
Figure 1-6 Electrical box inputs/outputs
This conguration may vary depending on installed options, etc.
CLEANUP
Metal surfaces may have been protected by thick grease and/
or paper. Carefully remove these using a plastic paint scraper,
disposable rags and a light-oil such as WD-40.
CHIP TRAY
Check that the chip tray, Figure 1-5, can be pulled forward
without snagging coolant hoses and worklight wiring. Use ca-
ble ties if necessary.

5Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
INITIAL CHECKS
Read Section 3 if unsure about any item in the following
BEFORE connecting power, do the following:
1. Visually check the entire machine for possible distur-
bance in shipping, including the motor, Vee belts and
external gears under the belt cover left of the headstock.
Replace the belt cover.
2. Check oil level (sight glasses) in the headstock, the car-
riage feed gearbox, and the apron. See Section 4.
3. If a chuck or faceplate is installed, check tightness of the
six Camlocks on the spindle nose, Section 3.
4. Lower the chuck guard, photo on page 1.
5. Check the spider, left-hand end of the spindle. Locknuts
on the four clamp screws should be tight. Make sure that
the clamp screws clear the cover when the spindle is
rotated by hand
7. Set the H-L gear levers to the lowest spindle speed, 60
rpm. Make sure the gears are properly meshed by "jig-
gling while shifting" — rotate the chuck back and forth by
hand while moving the levers into position. Make certain
that the motor control lever is set to OFF, mid-travel,
Figure 1-7.
Figure 1-7 Motor control lever
Mid-travel OFF, DOWN Forward, UP Reverse
Figure 1-8 Front panel controls
8. Set the Saddle Feed Direction lever to its center (OFF)
position, Figure 1-8.
9. Check that there are no clamps or locks on moving parts.
10. Check that the footbrake treadle is released (UP).
11. Set the saddle and cross slide to approximate mid-travel.
12. Connect 220 Vac power. The power lamp, Figure 1-8,
should light, unless a circuit breaker in the electrical box
has tripped.
13. Be sure the Emergency Stop (E-Stop) button has not
been pushed in (it should pop out when twisted clock-
wise).
14. Shift the motor control lever DOWN. The spindle should
turn Forward, counter clockwise, viewed at the chuck
(nose) end. The control system can be rewired for
DOWN = Reverse, see the electrical diagram, Section 5.
15. Check the emergency function by pressing the E-Stop
button. The motor should stop. If this doesn’t happen,
the E-stop function is defective, and needs attention.
16. Reset (twist) the E-Stop button to restore power.
17. Check that the chuck guard switch stops the motor when
the guard is swung up.
18. Check that the belt cover interlock stops the motor when
the belt cover is removed.
19. Check that the footbrake stops the motor.
20. Return the motor control lever to OFF, mid-travel. The
motor should stop.
21. Shift the motor control lever UP. The spindle should
Reverse, clockwise rotation, viewed at the chuck (nose)
end. The control system can be rewired for UP = For-
ward, see the electrical diagram, Section 5.
Do not change speed when the motor is running.

6Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
OPTIONAL TEST RUN PROCEDURE
Run the spindle for a few minutes, forward and reverse, at a
selection of the available 8 speeds.
The carriage feed gearbox should also be run at this time, but
rst make certain that the leadscrew and feed shaft oilers at
the tailstock end have been lubricated.
Also note: In initial tests, because the saddle and cross slide
should rst be exercised manually, the leadscrew split-nut
should be disengaged — ditto the saddle/cross-slide power
feed lever, Figure 1-9. The power feed lever can be either in or
out, but it should be centered, neither up nor down.
ALIGNING THE LATHE
The most important attribute of a properly set up lathe is its
ability to “machine parallel”, to cut a cylinder of uniform diam-
eter over its entire length. In other words, no taper.
Leveling of the lathe is a part of this, see earlier in this section.
Equally important is the alignment of the center-to-center axis
with the lathe bed, as seen from above. [Vertical alignment is
nowhere near as critical, rarely causing taper unless the lathe
is damaged or badly worn.] For more information see the nal
pages of Section 4, Servicing the Lathe.
After the initial test run, perhaps with a few additional hours of
machine time, some users drain and rell the headstock and
carriage feed gearbox. Lubricants are specied in Section 4.
Other users prefer to delay this service action for at least 50
hours of running time. No specic recommendation is given by
Precision Matthews.
Figure 1-9 Feed control levers on apron
Saddle Power feed lever OUT & UP to engage. Cross-slide Lever IN
& DOWN to engage. Test for dis-engagement by turning the saddle
and cross-slide handwheels.

7Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Section 2 FEATURES & SPECIFICATIONS
MODEL PM-1440GS Lathe
General information
This is a gap-bed lathe with 2-axis DRO designed for day-in, day-out use in the larger model shop. Distance be-
tween centers is 40in., swing over the bed 14 in. With an all-up weight of 1800 lb, plus 8 spindle speeds from 60
to 1800 rpm, the PM-1440GS is a robust heavy-duty machine. The spindle nose is D1-5 Camlock. A quick-change
carriage feed gearbox provides a full range of leadscrew ratios for U.S. and metric screw cutting, together with an
independent power feed for both saddle and cross slide. The power feed shaft is driven through a friction clutch
that allows the saddle to be stopped precisely at any point along the bed.
The 2-inch bore spindle comes with a stock-centering spider and MT6 internal taper. It runs on high-precision
NSK tapered-roller bearings, and is driven by a 3 HP (2200 W) 220 Vac single-phase motor. A treadle-operated
drum brake stops the spindle instantly, even at the highest speeds. A circulating coolant system is installed in the
right hand stand cabinet.
Accessories included
• 8 in. 3-jaw self centering chuck with two sets of jaws,
in-facing and out-facing
• 8 in. 4-jaw independent chuck with reversible jaws
• 200 Series precision wedge-type Quick Change
toolpost, with 5 toolholders
• Steady rest
• Follower rest
• Micrometer saddle stop
• Worklight
PM-1440GS Floor plan: dimensions approximate (not to scale)

8Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
PM-1440GS SPECIFICATIONS
Including stand: Width 71-1/2 in. x Height 51 in. x
Depth 31 in. (full range cross slide motion)
Footprint: 71-1/2 in. wide x 24 in. deep
Bed length 54 in.
Weight, approximate:1800 lb net
Power requirement
220 - 240Vac, 60 Hz, 1Ø, 12A full load
Motor TEFC type, cap start, 2.2 kW (3 HP), 1725 rpm
Work envelope
Center to center 40 in.
Spindle face to tailstock quill face 43-1/4 in.
Gap insert length 7-1/2 in.
Swing over gap 19-3/4 in. diameter
Swing over bed 14 in. diameter
Swing over cross slide 8-3/4 in. diameter
Saddle travel 38 in.
Cross-slide travel 7-3/4 in.
Compound (top slide) travel 3-3/4 in.
Drive system
(Belt drive with 8-speed gearbox)
Low range, rpm 60, 100, 170, 265
High range, rpm 420, 690, 1150, 1800
Carriage drive, thread cutting Leadscrew 8 tpi
Inch threads Choice of 42, from 4 to 112 TPI
Metric threads Choice of 44, from 0.1 mm to 7 mm pitch
Saddle drive, turning operations Choice of feed rates from 0.002 to 0.118 in./spindle rev
Cross slide drive, facing operations Choice of feed rates from 0.0005 to 0.03 in./spindle rev
Spindle
Chuck/faceplate attachment D1-5 Camlock
Internal taper MT6
Spindle bore Clearance for 2 in. diameter
Spindle length 17 in. overall
Tailstock
Internal taper MT4
Quill travel 4 in.
Work holding
3-jaw chuck, 8 in., self-centering (scroll) Reversible jaws
4-jaw chuck, 8 in., independent
Faceplate
Center rest (steady rest) capacity Up to 3 in. diameter
Follower rest capacity Up to 1 in. diameter
Dimensions, approximate overall, incl. stand

9Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Everyday precautions
• This machine is intended for use by experienced users familiar with metal-
working hazards.
• Untrained or unsupervised operators risk serious injury.
• Wear ANSI-approved full-face or eye protection at all times when using the
machine (everyday eyeglasses are not reliable protection against ying par-
ticles).
• Wear proper apparel and non-slip footwear – be sure to prevent hair, clothing
or jewelry from becoming entangled in moving parts. Gloves – including tight-
tting disposables – can be hazardous!
• Be sure the work area is properly lit.
• Never leave chuck keys, wrenches or other loose tools on the machine.
• Be sure the workpiece, toolholder(s) and machine ways are secure before
commencing operations.
• Use moderation: light cuts, low spindle speeds and slow table motion give
better, safer results than “hogging”.
• Don’t try to stop a moving spindle by hand – allow it to stop on its own.
• Disconnect 220 Vac power from the lathe before maintenance operations
such as oiling or adjustments.
• Maintain the machine with care – check lubrication and adjustments daily
before use.
• Clean the machine routinely – remove chips by brush or vacuum, not com-
pressed air (which can force debris into the ways).
No list of precautions can cover everything.
You cannot be too careful!

10 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Section 3 USING THE LATHE
DRIVE TRAIN
Double-groove pulleys connect the motor to the gearbox, Fig-
ure 3-3. Belt tension will not usually require attention. If nec-
essary, loosen the three hex head bolts securing the motor,
Figure 3-4. Adjust the motor to re-tension. Make certain the
motor is properly aligned, then re-tighten the bolts.
What is not in this section ...
The PM-1440GS is a conventional engine lathe that requires
little explanation except for details specic to this particular
model — speed selection, thread cutting, and the saddle/
cross-slide power feed system. Because the user is assumed
to be familiar with general purpose metal lathes, this section
contains very little tutorial.
MOTOR CONTROLS Figure 3-1
Figure 3-1 Main control panel
Before doing ANYTHING, check the installation instruc-
tions and power-up procedure in Section 1
STOP the motor before changing speed
Don't use JOG unless the gears are fully meshed
Figure 3-3 Vee belts & external change gears
Firm nger
pressure here
should deect
the Vee belt
about 1/4"
JOG FEATURE
"Jog" is momentary-type push-button, active only if the Motor
Control lever is in the mid-travel (OFF) position, Figure 3-2.
Press the button briey to "nudge" the spindle in reverse by a
few degrees. Jog can be used to reposition the chuck and/or
workpiece, especially when low spindle-speed gearing makes
hand rotation di󰀩cult.
The control system can be rewired for "Forward Jog", see the
electrical diagram, Section 5.
Figure 3-2 Motor control lever
Mid-travel OFF, Down FORWARD, Up REVERSE
Before connecting power to the lathe, be sure the Motor Con-
trol Lever on the apron is set to OFF, Figure 3-2. Connect the
lathe to a 220 Vac outlet — the POWER lamp should light —
then operate the Motor Control Lever to run the spindle in the
desired direction.
Check that the following interlocks function correctly:
• E-Stop button
• Chuck guard
• Belt cover (to the left of the headstock)
• Footbrake

11 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
SPINDLE SPEEDS
The PM-1440GS has an eight-speed headstock gearbox with
two shift levers, L-H & Speed Selection, Figure 3-1. Before
changing speed, use the Motor Control lever to STOP THE
MOTOR, then move the shift levers to the desired setting. This
may need a little patience because it is not always possible to
go directly from one mesh to another. Move the spindle back
and forth by hand while trying to ease the lever into its detent
(meshed) position. Don’t use the JOG button in this pro-
cess — this may cause gear damage.
Figure 3-4 Motor attachment bolts
CHUCKS & FACEPLATE
The spindle nose on the PM-1440GS accepts D1-5 Camlock
chucks, faceplates and other work holding devices.
A D1-5 chuck or faceplate is held by six threaded studs, each
with a D-shape crosscut to engage a corresponding cam in
the spindle nose, Figures 3-5, 3-6. The function of the cams is
to pull the chuck backplate inward to locate its internal taper
rmly on the spindle nose.
Figure 3-6 Camlock stud
TO INSTALL A CHUCK
Disconnect the 220V supply from the lathe!
D1-5 chucks and faceplates are heavy, some more than 30
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. Some
users add packing pieces, even custom-made cradles, to as-
sist “straight line” installation and removal.
Before installing make certain that the mating surfaces of the
chuck/faceplate 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. Select the highest spindle speed (1150 rpm) to allow easier
hand rotation of the spindle. (Alternatively, try moving the
speed selection levers between detents to nd a “between
teeth” condition to disengage the gear train.)
CARRIAGE FEED DIRECTION
The lever below the speed selectors on the front panel, Figure
3-1, determines whether the saddle feed is right to left — the
usual direction for turning and thread cutting — or reversed.
The selected direction applies to both the leadscrew and the
saddle/cross slide power feed.
Before changing feed direction, STOP THE MOTOR. Hand-
turn (jiggle) the spindle while feeling for the mesh, as above.
To disengage the power feed, set the Saddle Feed lever to its
mid-position.
SPINDLE SPEED (RPM)
H RANGE 1150 1800 690 420
L RANGE 170 265 100 60
Alongside each stud is a stop screw, the head of which ts
closely in a groove at the threaded end of the stud. The func-
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
out on the bench.
Figure 3-5 D1-5 faceplate
All stop screws must be present & fully tightened!
Camlock action can jam any stud lacking a stop
screw — a serious problem.

12 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Figure 3-8 Installing a Camlock chuck
Figure 3-9 Cam in locked condition
TO REMOVE A CHUCK OR FACEPLATE
Disconnect the 220V supply from the lathe!
Protect the lathe bed, as Figure 3-7. While supporting its
weight, turn each of the cams to 12 o’clock, Figure 3-8, then
remove the chuck. If the chuck does not come free, try tapping
the backplate gently with a soft (dead blow) mallet.
CROSS SLIDE & COMPOUND
The cross slide and compound, Figure 3-10, both have 10 TPI
leadscrews, with 100-division graduated collars, so each divi-
sion represents a “real” motion of 0.001”. On the cross slide
dial, only, this shows as 0.002” per division, meaning that a
0.001” depth of cut reduces the diameter of the workpiece by
0.002”.
2. Turn the spindle by hand, checking that all six cam markers
are at 12 o’clock.
3. While supporting its full weight, install the chuck without
tilting, see Figure 3-8, then gently turn each of the cams
clockwise — snug, rm, but not locked in this rst pass.
Figure 3-7 Protect the lathe bed
4. 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.
5. If any cam marker is not within the Vees, rst be sure that
there is no gap between chuck backplate and spindle
ange. Also, remove the chuck to inspect the studs — burrs
can be a problem, hone if necessary. If there are no vis-
ible problems, the stud in question may need adjust-
ment as follows:
• Remove the stop screw from the stud.
• If the cam marker in question can’t get to the rst Vee (3
o’clock), back the stud OUT one full turn, then replace the
stop screw.
• If the cam marker goes beyond the second Vee (6 o’clock),
screw the stud IN one more turn, then replace the stop
screw.
• If the markers are correctly aligned, repeat the tightening
sequence as step 3, light force. Repeat the sequence two
more times, rst with moderate force, then fully tighten.
Figure 3-10 Cross slide and compound dials

13 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Figure 3-13 External gear set F To change gear sets loosen the 17
mm nut, arrowed, then swing down the support casting (quadrant).
SADDLE FEED GEARBOX
Stop the motor before changing feed direction or rate
The saddle feed can be to the left, right, or disengaged, as se-
lected by the Saddle Feed Direction lever on the main control
panel, Figure 3-1.
TAILSTOCK
The tailstock leadscrew has a 10 TPI thread, with 4 inch travel.
A graduated collar on the tailstock handwheel reads 0.001”/
division. To remove tooling from the tailstock taper (MT4) turn
the handwheel counter-clockwise (handle end view) until re-
sistance is felt, then turn the handle a little more to eject the
tool. Conversely, to install a taper tool make certain that the
quill is out far enough to allow rm seating.
For taper turning the tailstock may be o󰀨set by adjusting set
screws on either side, Figure 3-11. To move the tailstock to
the front, for instance, the screw on the lever side would be
unscrewed, then the opposing set screw would be screwed in
to move the upper assembly.
A visual indication of the o󰀨set is provided by a scale on the
back surface, but this is not a reliable measure for precise
work. In practice, the only way to determine the o󰀨set precisely
is to "cut and try' on the workpiece, or scrap stock, homing in
on the correct degree of o󰀨set in small increments.
The same issues arise when re-establishing "true zero" of the
tailstock, in other words returning it to the normal axis for rou-
tine operations. One way to avoid cut-and-try is to prepare in
advance a bar of (say) 1" diameter quality ground stock, with
precise center drillings at both ends (do this by indicating for
zero TIR in a 4-jaw chuck, not in a 3-jaw unless known to be
predictably accurate). The prepared bar can then be installed
between centers and indicated along its length.
Figure 3-11 Tailstock
Offset scale
Offset adjust
Offset
adjust
Figure 3-12 Saddle feed gearbox controls
The rate of power feed relative to spindle speed is set by the
four shifter knobs below the main control panel, Figure 3-12.
The W-X-Y knob at right determines which is the driven shaft,
leadscrew (Wand Y) or feed shaft (X).
Select W to cut U.S. threads (TPI), Y for metric threads
A distinctive feature of the PM-1440GS is its ability to cut a
wide range of U.S. and metric threads with only two external
gear sets, Figures 3-13 and 3-17.

14 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
ENGAGING THE POWER FEED
Power feed controls are located on the apron, Figure 3-14.
The split-nut lever engages the leadscrew, and is typically
used only for screw cutting (W-X-Y knob on gear box set to
either W or Y).
The power feed lever is active only when the feed shaft is
rotating, W-X-Y knob on gear box set to X. When the lever is
pushed LEFT (cross slide) or RIGHT (saddle), the lever tip is
captive to prevent incorrect up/down movement.
When engaging power feed, move the lever gently, feeling
for the gears to mesh as you go. If the gears don’t engage at
the rst try, use the appropriate handwheel to jog the saddle or
cross slide, whichever one you wish to move under power.
The split-nut lever, used only for screw cutting, cannot be
engaged unless the power feed lever is NEUTRAL, neither
up or down
FEEDSHAFT CLUTCH
The clutch shown in Figure 3-15 disengages the power feed if
the saddle or cross slide hits an obstruction when power feed-
ing, thus minimizing the potential for damage. This could be
the result of either an accidental event, or deliberately stopping
the saddle at a precise location set by the stop, Figure 3-16.
The clutch comprises a pair of spring loaded steel balls bear-
ing on a detent disc driven by the saddle feed gearbox. Spring
pressure is adjusted by two set screws on either side of the
feed shaft, arrowed in Figure 3-15. Setting the spring pressure
is a process of aiming for the best compromise between too
high — damaging feed pressure — and too low, which might
mean unexpected stopping for no good reason.
Setting the clutch to work reliably with the micrometer carriage
stop is a good example of such a compromise: start with low
spring force, then work up in small increments until the car-
riage stops in the same location (say ± 0.002”, assuming a
constant depth of cut and feed rate).
SADDLE STOP
The stop assembly, Figure 3-16, has a micrometer-style collar
graduated in 0.001 in. divisions. It can be clamped at any point
along the lathe bed (two M6 socket head screws on the under-
side secure the clamp plate to the block). Make certain that the
stop rod seats rmly on the saddle casting.
Figure 3-14 Feed control levers on apron
Saddle Power feed lever RIGHT & UP to engage. Cross-slide Lever
LEFT & DOWN to engage. Test for dis-engagement by turning the
saddle and cross-slide handwheels.
Figure 3-15 Feedshaft clutch
Figure 3-16 Micrometer saddle stop

15 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Figure 3-17 External gear sets
Screw cutting operations use only sets F and G (special-purpose set
H is for worm cutting). Convert from F to G by exchanging the 33T and
66T gears.
EXTERNAL GEAR RATIOS
Referring to the gear tooth numbers in Figure 3-17, set G
drives the saddle 4 times faster than F. This means that G is
for coarse threads/feeds, and F is for ne.
Ratio of external gear sets G & H relative to F
F = 1 (ne thread)
G = F x 4 (coarse thread)
H = F x 3.14 = F x �
[Gear set H is the "pi factor" that enables the PM-1440GS to
convert from the circular pitch of a worm wheel to the linear
pitch of a matching worm.]
When exchanging gears, make sure that the external gears are
properly meshed. One way to gauge the gap between gears
is to insert a scrap of paper between the teeth as a separator
(use standard printer paper, about 0.004" thick).
Be sure the gears are lubricated!
Saddle X slide Saddle X slide Saddle X slide Saddle X slide
FATX 0.002 0.0005 0.002 0.0006 0.003 0.0007 0.003 0.0008
FASX 0.003 0.0009 0.004 0.0012 0.005 0.0014 0.006 0.0016
FARX 0.007 0.0019 0.008 0.0023 0.010 0.0028 0.012 0.0032
FBRX 0.017 0.0046 0.021 0.0058 0.025 0.0069 0.029 0.0081
GBSX 0.034 0.0092 0.042 0.0115 0.050 0.0139 0.059 0.0162
GBRX 0.067 0.0185 0.084 0.0231 0.101 0.0277 0.118 0.0323
1
3
6
8
POWER FEED RATES
The following table lists inches of travel per revolution of the
spindle. Saddle motion is about 3.6 times cross slide motion.
SCREW CUTTING — U.S. THREADS
UN Coarse & UN Fine
The following table lists threads per inch (TPI).
Gear Set F cuts all UNF threads from #0 to 3/4", plus UNC
from #1 to 3/8"
Gear Set G cuts all UNF threads from 7/8" to 1-1/2", plus UNC
from 7/16" to 1-1/2".
1 2 3 4 5 6 7 8
GCTY 4 4-1/2 5 5-1/2 5-3/4 6 5-1/2 7
GCSY 8 9 10 11 11-1/2 12 13 14
GBY 9-1/2 9-1/2 9-1/2 9-1/2 9-1/2 9-1/2 9-1/2 9-1/2
FCTY 16 18 20 22 23 24 26 28
FCSY 32 36 40 44 46 48 52 56
FBY 38 38 38 38 38 38 38 38
FCRY 64 72 80 88 92 96 104 112

16 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
WORM CUTTING — U.S.
The following table lists DP (Diametral Pitch) values for worm-wheels, and the gearbox settings to cut
matching worms. Example: a 16DP worm wheel has a Circular Pitch of π ÷ DP = 3.142 ÷ 16 = 0.1963".
This is the distance between a point on one tooth of the worm-wheel and the corresponding point on its
adjacent tooth.
A matching worm has a Linear Pitch of the same value. In other words, the "thread pitch" of the worm
is also 0.1963". In the table the setup for this pitch is HCTY-1. Compare this with GCTY-1 (U.S. threads
table, preceding page) for a 4 TPI thread, pitch 0.25". Gear set H runs the leadscrew slower (π/4) than G,
so the worm pitch is 0.25 x π/4 = 0.1963".
The following table lists Module numbers for metric worm-wheels, and the gearbox settings to cut match-
ing worms. (Module is the inverse of diametral pitch, but with the pitch circle diameter measured in mil-
limeters instead of inches.) Example: a Module 1.5 worm-wheel has a Circular Pitch of π x 1.5 = 4.712
mm. This is the distance between a point on one tooth of the worm-wheel and the corresponding point
on its adjacent tooth.
A matching worm has a Linear Pitch of the same value. In other words, the "thread pitch" of the worm
is also 4.712 mm. In the table the setup for this is HBRW-6. Compare this with GBRW-6 (Metric threads
table, preceding page) for a thread of 6 mm pitch. Gear set H runs the leadscrew slower (π/4) than G, so
the worm pitch is 6 x π/4 = 4.712 mm.
1 2 3 4 5 6 7 8
HCTY 16 18 20 44 23 24 26 28
HCSY 32 36 40 44 46 48 52 56
HBY 38 38 38 38 38 38 38 38
HCRY 64 72 80 88 92 96 104 112
1 2 3 4 5 6 7 8
HATW 0.1 0.125 0.15
HASW 0.2 0.225 0.25 0.275 0.2875 0.3 0.325 0.35
HBTW 0.375
HARW 0.4 0.45 0.5 0.55 0.575 0.6 0.65 0.7
HBSW 0.5625 0.625 0.6875 0.75 0.8125 0.875
HBRW 1 1.125 1.25 1.375 1.5 1.625 1.75
SCREW CUTTING — METRIC THREADS
The following table lists thread pitch in mm.
Gear Set F cuts all ne threads from M1 to M18 diameters,
plus all coarse threads from M1.6 to M12 diameters, with a
single exception (M5 x 0.8).
Gear Set G cuts all coarse threads from M14 to M68 diam-
eters, plus M5 x 0.8.
1 2 3 4 5 6 7 8
FATW 0.1 0.125 0.15
FASW 0.2 0.225 0.25 0.3 0.35
FARW 0.4 0.45 0.5 0.55 0.6 0.65 0.7
FBSW 0.75 0.875
GASW 0.8 0.9 1.1 1.2 1.3 1.4
FBRW 1 1.25 1.5 1.75
GARW 1.6 1.8
GBSW 2 2.25 2.5 2.75 3 3.25 3.5
GBRW 4 4.5 5 5.5 5.75 6 6.5 7
WORM CUTTING — METRIC

17 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
COMPOUND SETUP FOR THREAD CUTTING
Thread cutting on the lathe is unlike most other turning opera-
tions, for two reasons: 1. The cutting tool must be precisely
ground with an included angle of 60 degrees for most Ameri-
can and metric threads, and; 2. It is preferable to feed the tool
into the workpiece at an angle so it cuts mostly on the left ank
of the thread. The correct angle relative to the cross slide (zero
degrees) is a subject of debate — should it be 29, 29-1/2 or 30
degrees? Many machinists prefer 29 degrees because it holds
the cutting tool marginally clear of the right ank of the thread,
close enough for cleanup of the ank while at the same time
avoiding appreciable rubbing.
The 45o- 0o- 45oscale on the compound is not directly helpful
in setting the thread cutting angle, but it can be used for that
purpose if a second reference mark is applied to the cross
slide. First make certain that the compound is truly aligned
with the lathe axis when 0oon the scale is on the cross slide
Figure 3-18 Setting up the compound for 30o infeed
A new reference mark is stamped on the cross slide at 30 degrees.
To set the compound for thread cutting, rotate it clockwise to bring the
right hand 30oscale mark in line with the new reference mark. For 29o
rotate the compound 1 degree more.
For metric and UNC/UNF threads the tool is ground to 60o (in-
cluded angle). It is installed so that its anks are exactly 30o
either side of the cross axis, ideally with the compound o󰀨-
set as Figure 3-18. Single-point threads are cut in 10 or more
successive passes, each shaving a little more material o󰀨 the
workpiece.
To make the rst thread-cutting pass the leadscrew is run at
the selected setting (table on page 15), and the carriage is
moved by hand to set the cutting tool at the starting point of the
thread. With the tool just grazing the workpiece, the split-nut
lever is lowered to engage the leadscrew. This can be done at
any point, provided the split-nut remains engaged throughout
the entire multi-pass process.
When the rst pass is completed, the tool is backed out clear
the workpiece (using the cross slide), and the spindle is re-
versed to bring the saddle back to the starting point. The cross
slide is returned to its former setting, then the tool is advanced
a few thousandths by the compound for the next pass. Each
successive pass is done in the same way, each with a slightly
increased infeed setting of the compound.
Many users working on U.S. threads save time by disengag-
ing the split-nut at the end of each cutting pass, reversing the
reference mark — do this by indicating against a ground bar
between centers while advancing the indicator using only the
compound. Allow for the variance, if any, when applying the
new reference mark. Grind a chisel edge on a 1/4 in. square
HS tool bit, align it precisely on the left hand 30oscale mark;
then rap the tool bit sharply with a hammer.
CUTTING PROCEDURE FOR TPI THREADS
This procedure assumes that a single point thread cutting tool
will be used, and that the threading dial assembly has been
pivoted forward to engage its worm wheel with the leadscrew,
Figure 3-19.
The threading dial cannot used for metric threads! The
split-nut on the apron must be left engaged throughout
the entire process.
Figure 3-19 Threading dial

18 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
saddle by hand, then re-engaging, usually by reference to the
threading dial, Figure 3-20.
If the TPI number is divisible by 2 re-engagement can be done
at any line on the threading dial.
For all other TPI numbers every engagement, including the
rst, must at the point where a specic line on the thread-
ing dial comes into alignment with the datum mark. If not, the
second and subsequent passes will be out of sync. In some
cases, Figure 3-20, there is a choice of lines for re-engage-
ment, but in every case the process calls for careful timing.
[NOTE: Disengagement and re-engagement of the split-nut is
not applicable to metric threads].
Typical depths of cut per pass vary from an initial 0.005” or so,
to as little as 0.001”, even less. A nishing pass or two with
increments of only 0.0005” (or none at all) to deal with the
spring-back e󰀨ect can make all the di󰀨erence between a too-
tight thread and one that runs perfectly.
Assuming that the compound is set over at between 29 and
Figure 3-20 Threading dial visualization for selected U.S. threads
Minimize wear by swinging the dial indicator assembly away from
the leadscrew when not in use
30 degrees, the total depth of cut is approximately 0.69 times
the thread pitch, P (this equates to a straight-in thread depth of
0.6 times P). There may be a need for a few thousandths more
in-feed than 0.69P, almost certainly not less.
USING THE THREADING DIAL
Referring to Figure 3-20, the general rules are:
1. Divide the TPI value by 2: If this gives a whole number,
example 10/2 = 5, re-engage at any line on the dial. Spe-
cial case: if the result of dividing by 2 is an even number,
example 12/2, you can re-engage midway between lines.
2. If the TPI value is a whole number not divisible by 2, ex-
ample 7, re-engage on the start line, or any line at right
angles to it. In the table this shows as 1-3-5-7 (but could
be 2-4-6-8, etc.).
3. If the TPI value is fractional, but becomes a whole number
when multiplied by 2, example 4-1/2, re-engage only on
the start line, or its diametrical opposite. In the table this
shows as 1-5-1 (but could be 2-6-2, etc.)
If in doubt, re-engage on the start line!

19 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
GAP BED
A 7-1/2 inch long section of the bed at the headstock end can
be removed to allow turning of diameters up to 19-3/4 in., Fig-
ure 3-21.
To remove the gap insert back in the pusher screw one or two
turns, then remove the four large socket head screws secur-
ing the insert to the bed. To minimize cosmetic damage, cut
through the paint and ller along the joint between insert and
bed using a sharp knife or pointed scraper.
Jack out the two locating pins arrowed (exposed threads and
hex nuts), then tap the insert free with a soft-face mallet.
Before re-installing the insert, be certain that all mating surfac-
es are scrupulously clean. Set the insert in place, lightly tap in
the two locating pins, then install the four large bolts (snug, but
not fully tightened). Jack the insert to the right with the pusher
screw to close the gap, if any, between the ground surfaces of
the bed ways at the join (a visible parting line is acceptable, but
a discontinuity that snags the saddle is not). If a satisfactory
join cannot be achieved, it may be necessary to remove and
reinstall the insert from scratch.
Figure 3-21 Gap insert
Pusher
screw
STEADY & FOLLOWER RESTS
The hinge-type steady rest, Figure 3-23, can be mounted any-
where along the lathe bed. It makes possible cutting opera-
tions on long, slender workpieces between centers, or held at
one end by chuck. The steady rest is often used in combina-
tion with the saddle-mounted follower rest, Figure 3-24.
Figure 3-23 Steady rest (representative)
LOCKING THE SLIDES
Figure 3-22 Compound & saddle locks
When face-cutting large diameter surfaces, for instance, it is
often desirable to lock the saddle. Less frequently it can be
helpful to lock, or at least sti󰀨en, sliding motion of the com-
pound, Figure 3-22.
Access to the saddle lock screw may be limited by the DRO
scale cover. If so, it may be desirable to replace the installed
screw (socket head) with a conventional hex head, or a ratch-
eting lever screw.
To set the ngers on the workpiece, rst swing open the upper
casting. Make certain that all three ngers are freely adjustable
by thumbwheel. If not, loosen and re-lock the set screws (ar-
rowed). Raise the two lower ngers to just touch the workpiece
— not deecting it — then close and secure the upper casting.
Lower the top nger to just touch the workpiece, clamp the
frame, then apply oil at the point of contact.
The follower rest, Figure 3-24, is secured to the saddle with
two 8 mm socket head screws. Adjust the follower ngers as
described for the steady rest.

20 Copyright © 2020 Quality Machine Tools, LLCPM-1440GS v3 2020-10
Figure 3-24 Follower rest (representative)
SPIDER
A spider is installed on the left hand end of the spindle. Its
function is to stabilize long workpieces that would otherwise
wobble. To set up the spider, back out its four clamp screws,
then chuck the workpiece using moderate jaw pressure. The
aim is now to match runout at the spider end with runout at
the chuck end (usually adjusted for zero unless a deliberate
o󰀨set is called for). Progressively tighten the spider clamp
screws to grip the workpiece rmly, without deecting it.
Re-check runout at the chuck end, correcting one or more of
the spider screws if necessary. Fully tighten the chuck. Some
amount of iteration may be necessary to achieve similar run-
out at both ends. When satised with the setup, fully tighten
the locknuts on the spider screws, then re-check.
Figure 3-25 Spider attachment