Data Sheet

-40-
the ball bearing thrust and two washers from the collar
and reinstall them in the new Z-axis thrust collar in the
same order (See Figure 83). Install the new collar on the
leadscrew shaft and secure it to the bed with the at head
screw.
8. Install the remaining handwheel and encoder unit onto the
Z-axis leadscrew. Lift up on the saddle assembly until the
washer and shoulder of the leadscrew are all the way up
against the bottom of the collar. Then push down on the
handwheel and tighten its set screw, being sure to tighten
it against a new spot on the shaft. If installed on your
machine, reinstall the 5-40 x 3/8" at head screw through
the center of the Z-axis handwheel and into the end of
the leadscrew. See “Adjusting the Z-axis handwheel” on
page 41 for more details on adjusting this screw. Install
the pickup housing over the handwheel unit as shown
in Figures 4 and 5. When nished, the cable should exit
toward the left when viewed from the front.
Leadscrew Handwheel Position on the Model 4400 Lathe
The die cast base on the Model 4400/4410 long bed lathe is
relieved so that the bed and base align. The lip on the bottom
of the machined area will keep the sensor housing from being
able to be rotated straight down. The solution to this is to orient
the housing as shown in Figure 84 below. The joint between
the two halves of the housing now becomes the witness mark
against which you read the handwheel markings. On the Model
4400/4410 lathe, the bed and base are ush at the end, so the
housing can be positioned straight down as is shown in the
other gures.
JOINT BETWEEN UPPER AND
LOWER HOUSING HALVES
FIGURE 84—On the long bed lathe, the leadscrew handwheel
sensor housing must be positioned as shown.
Making Sure the Housings Do not Move
The sensors that read gear-tooth position as you turn the
handwheel are located in the bottom of the handwheel housing.
If the housing moves, it is the same as if you moved the
handwheel, because it changes the relationship between the
sensor and the gear tooth. Therefore, the housing should be
anchored in place so that it cannot be inadvertently moved.
The screws that hold the two halves together go into plastic,
and overtightening them can strip the threads out of the hole.
If the housing rotates too easily when the screws are tightened,
you can remove the housing shell and sand the mating surfaces
on a piece of sandpaper on a at surface until they grip the
collar more tightly. If this doesn’t do the job, another solution
is to place a drop of “super glue” between the plastic housing
and the metal collar once the housing is positioned where you
want it. This will keep it in place but can still be broken loose
if you need to later.
Installing the RPM Sensor
1. Reinstall the headstock/motor/speed control onto the lathe
or milling column.
2. Peel o the backing and apply the 2-1/2" round sticker
to the pulley. (HINT: A little liquid window cleaner
on the pulley allows the sticker to be repositioned and
bubbles squeezed out before it adheres. Once the liquid
is squeezed out and dries, the adhesive on the sticker will
stick ne.)
3. Locate the RPM sensor by holding it in the position shown
in Figure 7. Mark the center of the hole on the plastic belt
housing and drill a 1/16" hole. Fasten the sensor to the
belt housing using the self-tapping screw provided. (Do
not overtighten or you can strip the threads.) A plastic tie-
wrap is provided to secure the sensor lead to the motor’s
power cord to keep it out of the way.
NOTE: If you have a machine with an older AC/DC motor
that does not have a plastic belt guard, the RPM sensor can be
mounted in the proper position over the pulley by attaching
it to the motor mounting bracket. Locate and mark where the
hole should be drilled. Remove the motor and drill a hole
through the bracket. You can use a self-tapping sheet metal
screw or a bolt and nut through the hole, or you can tap the
hole to match the thread of the bolt you use.
Hooking up the Connecting Cables
Plug the cable connector from each encoder unit into its
respective port on the display unit. The telephone type cable
connectors go in with the locking tab facing up when the unit
is lying on its back. The RPM sensor cable goes into the port
marked “Tach In.”
Plug the power adapter into the bottom hole marked “DC In,”
and plug the transformer into a 115 VAC (60 Hz.) source.
Check to make sure all three axes are functioning. Turn on the
motor and check to see that the RPM indicator is functioning.
Initializing Your Display for Inch or Metric Leadscrews
When you press the “Power” button to turn your system on,
the upper right corner of the display will read either “inch”
or “metric” mode. Normally, the DRO will be set up properly
when you receive it, but there is always a possibility it could
be set wrong. To set or change the system of measurement
your unit displays, follow these steps:
1. With the power o, unplug the power cable from the
display unit.
2. INCH—Hold down both the “Power” button and the
X-axis button while you plug the power cord back into
the display unit. After the display comes up, release the
buttons. The display should now read in inch dimensions.
3. METRIC—To initialize your display unit to read metric
dimensions, hold down the “Power” and “Y” buttons
while plugging the power cord back into the display unit.
Once initialized, the unit will always read in your chosen
system of measurement each time it is turned on unless
you change it.