Sherline Products WETTROTH 8100 User manual

WEAR YOUR
FORESIGHT IS BETTER
THAN NO SIGHT
READ INSTRUCTIONS
BEFORE OPERATING
SAFETY GLASSES
SHERLINE PRODUCTS INC. •3235 Executive Ridge •Vista •California 92081-8527 •FAX: [phone]
Toll Free Order Line: [phone] •International/Local/Tech. Assistance: [phone] •Internet: www.sherline.com
9/8/21
SHERLINE/WETTROTH
Mill Digital Readout
P/N 8100 (Metric P/N 8160)
The Digital Readout in the Modern Machine Shop
Digital readouts are popular on full-size mills because
they make the life of a machinist much simpler. They
make it easier to accurately set or change the table position
and eliminate errors caused by misreading handwheel
increments or losing track of multiple rotations. Now that
same convenience is available on tabletop size machines
with a DRO (Digital ReadOut) for Sherline mills. John
Wettroth designed the compact electronics package and
clever backlash compensation feature.
On industrial DROs, a sensor reads a highly accurate external
scale. On Sherline’s DRO, the sensor reads rotation of the
leadscrew. Because of the accuracy of Sherline’s precision
rolled leadscrew threads and the short travels on a machine
of this size, this system makes it possible to provide a
DRO with sufcient accuracy while maintaining a price
appropriate for a machine of this size and cost.
The kit can be installed on any Sherline mill, regardless of
age and is very easy to use. Remember that the directions
of movement of the mill are referred to as the X-axis (table
side-to-side), Y-axis (table in-out) and Z-axis (spindle up-
down). The readout of any axis can be set to zero at any
time with the push of a button.As you move the handwheels
you can read the table position to three and a half decimal
places on the digital readout. It is not necessary to keep
track of the number of handwheel rotations to gure the
stopping point on larger dimensions.This will be especially
appreciated when cranking in “negative” amounts. Backlash
is compensated for by setting it into the unit’s electronic
memory in increments of .0005". As a bonus, the package
also includes an electronic readout of spindle RPM at
all times.
NOTE: The DRO unit itself is accurate to within 1/100 of a
revolution of the screw. Example: On our 3/8-20 leadscrew,
the pitch is .050/rev.; therefore, .050/100 = .0005". The
accuracy on a 10 x 1mm leadscrew will be .01mm. On our
10 x 2mm ball screw, the accuracy will be .02mm.
Installing the DRO Components on Your Sherline Mill
The following instructions describe the steps required to
remove the existing handwheels and thrust collars and
replace them with the DRO encoder/handwheel units. It
is suggested that you remove the headstock and motor
assembly from the mill to make it easier to install the DRO
components. (“Left” and “Right” refer to the operator’s
left and right sides when facing the mill with the X-axis
handwheel on your right.)
1. Move the table all the way to the left. This will limit
movement of the leadscrew and help center the new
collar.
2. Move the table all the way to the front toward the
operator.
3. Raise the headstock all the way to the top of its travel.
4. Using a 3/32" hex wrench, remove all three handwheels
by releasing their set screws and sliding them off
their leadscrews. (If your mill has resettable “zero”
handwheels, loosen the collar locking knob and rotate
the collar until the hole lines up with the set screw. Then
use the 3/32" hex wrench to loosen the set screw and
remove the entire handwheel/collar unit.)
5. Using a 3/32" hex wrench, remove the 5-40 screws
holding the thrust collars on the X- and Y-axis
leadscrews. Remove the collars.
6. Clean each grooved thrust collar with a solvent like
acetone or lacquer thinner to remove any oil from the
surface. (You will later lock them in place in relation
to the plastic housing with "instant glue" and it will
not stick to an oily collar.) Using the existing screws,
install new grooved thrust collars on the X- and
FIGURE 1—Installing the
new thrust collar on the
X- and Y-axes
New Collar
Existing Screw Leadscrew Shoulder
Leadscrew

P/N 8100, Pg. 2 of 7
Y-axes, making sure the leadscrew is centered in the
collar. Make sure the screws are secure, but do not
overtighten. If a shim washer was present on your
existing leadscrew, reinstall it as it was before.
7. Install a new handwheel and encoder ring on the
X- and Y-axes. (The encoder ring has been factory
installed on the handwheel for easier assembly.) Note
that the X and Y handwheels are similar except on the
X-axis, the numbers on the handwheel face away from
the handwheel. On the Y-axis they face toward the
handwheel. Make sure the shoulder at the end of the
leadscrew thread is seated against the thrust collar and
the handwheel is pushed in tightly to remove end play
before tightening the set screw. On the X-axis, push
the table AWAY from the handwheel while pushing
the handwheel onto the leadscrew shaft. On the Y-axis,
hold the table (not the base) with one hand and push
the handwheel onto the shaft with the other. Rotate
the handwheel so that the set screw tightens on a new
part of the shaft. If you don’t, it will tend to pick up
its old indentation making it difcult to tighten it in a
new position.
See Figure 3 for orientation of the encoder housing. The
thicker shoulder inside the encoder should be facing
toward the thrust collar. It is easier to tighten the screws if
you install the units upside down with the screws coming
down from the top. Place the two halves of the shell over
the thrust collar and over the encoder ring and install the
four #2 x 3/8" self-tapping screws. Draw the screws down
until they seat snugly, but DO NOT OVERTIGHTEN or
you will strip the threads! Once tightened into position, the
unit can be rotated around until the screws and cable are
on the bottom.* When nished, the cable from the X-axis
encoder should come off to the rear, and the cable from the
Y-axis encoder should come off to the right.
*NOTE: The unit should be tight enough so that it doesn’t
move accidentally once positioned. If it 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 tightly enough.
8. Using a 1/8" hex wrench, remove the at head screw
that holds the Z-axis thrust collar to the column.
Remove the collar by lifting it up and off the Z-axis
1. First the shell is installed over the thrust
collar and handwheel upside down. (Left)
2. Then the shell is rotated into position
with the cable lead on the bottom. (Below)
FIGURE 2—Making sure the leadscrew is centered
FIGURE 3—(Above) Detail of the encoder housing showing
direction of installation
FIGURE 4—Installing the encoder unit over the thrust collar.
The unit can be installed upside down to make it easier to put
in the screws. It is then rotated into position and tightened to
lock it in place.
FIGURE 5—Rotating the unit into its proper position. (Note:
Handwheel/encoder unit not shown for clarity.)
FIGURE 6—Order of
washers and bearing
in Z-axis thrust collar
Existing Washers
and Ball Bearing
from old Collar
New Collar
Existing Washer
Flat Head Screw
Column
Leadscrew
Center Leadscrew before tightening screw
TOWARD THRUST COLLAR
THICKER SIDE OF HOUSING
AXIS COLLAR GROOVE

P/N 8100, Pg. 3 of 7
leadscrew. If the spacer washer sticks to the bottom
of it, remove it and reinstall it on the leadscrew shaft.
Then remove 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 6.) Install
the new collar on the leadscrew shaft and secure it to
the bed with the at head screw.
9. 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 "Adjustint the
Z-axis handwheel" on page 4 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.
10. 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. A good 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 mill.
2. Peel off the backing and apply the 2-1/2" round decal
to the pulley. (HINT: A little liquid window cleaner
on the pulley allows the decal to be repositioned and
bubbles squeezed out before it sticks. Once the liquid
is squeezed out and dries, the adhesive on the sticker
will stick ne.)
NOTE: You must make sure you have the correct tach
sticker for your machine. Use a 6-pulse (P/N P/N 81510)
tach sticker if your machine is a leadscrew machine, or a
5-pulse tach sticker (P/N P/N 87860) if your machine is a
ball screw machine.
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 mill 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 is
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 for DROs that
were purchased prior to 8/1/21, follow these steps:
1. With the power off, 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
Drill 1/16" hole and mount
sensor head using the self-
tapping screw provided.
Plastic Tie-Wrap
RPM Sensor
Vinyl Decal
FIGURE 7—Mounting the sensor to the belt housing

P/N 8100, Pg. 4 of 7
unit. Once initialized, the unit will always read in your
chosen system of measurement each time it is turned
on unless you change it.
The only difference between the inch and metric packages
is the number of divisions engraved into the handwheels.
The electronics package is the same for either and can be
set to read in either measurement system depending on the
leadscrews of the machine on which it is installed.
NOTE: Before you choose a mode, the mode must be for
the actual leadscrew or ball screw that is on your machine.
For example, if you have an Inch leadscrew on your machine,
you cannot use modes 2,3,5, or 6. You can only use modes
1 or 4. The DRO software calculations (and display) are
based on the actual screw that is on your machine.
NOTICE! On DROs sold before 8/1/21, the display does not
convert dimensions from inch to metric!
The DRO reads rotary handwheel movement and
converts it to a linear dimension based on a formula
assuming a certain leadscrew thread pitch. The DRO
must be set to agree with the leadscrews installed
on your machine to provide accurate measurements.
2021 DRO Mode Settings
We upgraded our DRO chip in 2021 in order to use the
DRO with our metric ball screw machines. We also made
a few other upgrades based on our customer feedback.
This new DRO system will offer the two original settings,
Modes 1 and 2.
• Mode 1 for use on an inch leadscrew machine with an
inch display
• Mode 2 for use on a metric machine with a metric
display.
Modes 3 through 6 are in addition to the original settings.
• Mode 3 is used for our ball screw machine with an
inch display.
• Mode 4 is used for an inch Leadscrew machine with
a metric display.
• Mode 5 is used for a metric Leadscrew machine with
an inch display.
• Mode 6 is used for our ball screw machine with a
metric display.
The chart in Figure 8 shows all six modes along with the
“Key Combinations” to use to activate each mode. The
initializing steps to activate Modes #1 and #2 are the same
as the original DRO instructions noted above for Inch
and Metric. To Initialize modes 3–6, use the same steps
of holding down the POWER ON button along with the
additional keys shown on the chart. Watch the display screen
when the DRO powers on to make sure that the “power up
display” that shows on the screen is correct. For example,
if you are initializing Mode #5, you hold down the Power
button along with the Y and Z buttons. When the display
comes on, the display should show “M1INT6,” then the
DRO display will come on.
NOTE: For more detailed information on setting up the
modes for DRO, please see the DRO Mode Instructions
https://sherline.com/wp-content/uploads/2021/07/dro_
mode_inst.pdf
Mode Key
Combination
Leadscrew
Pitch
Displayed
Units
Example
Display
Position
Resolution
Backlash
Entry Units
Power Up
Display Notes
1 ON + X .05"/Turn Inch + 1.0055 .0005" Inch ININT6
Original Inch Mode for
a machine with an inch
leadscrew
2 ON + Y 1 mm/Turn Metric + 25.41 .01 mm mm M1MMT6
Original Metric Mode for
a machine with an metric
leadscrew
3 ON + Z 2 mm/Turn Inch + 0.3937 0.0008" mm M2INT5
For a Ball Screw machine
showing the readout
in inches
4 ON + X + Y .05"/Turn Metric + 1.0055 .01 mm Inch INMMT6
For an Inch Leadscrew
machine showing the
readout in metric
5 ON + Y + Z 1 mm/Turn Inch + 1.0055 0.0004" mm M1INT6
For a Metric Leadscrew
machine showing the
readout in inch
6 ON + X + Z 2 mm/Turn Metric + 25.42 0.02 mm mm M2MMT5
For a Ball Screw machine
showing the readout
in metric
FIGURE 8—See page 6 for a full-size chart.
Setting the Backlash Compensation Values
To set backlash compensation for each axis, you must
rst measure to determine what the backlash is. Use a dial
indicator to determine how far the handwheel on each axis
rotates before the table starts to move. (If this amount is
excessive, see your instruction manual for instructions on
setting backlash. It should ideally be in the .003" to .005"
range.) Once the amount is determined, the backlash is
compensated for by setting it into the display unit’s memory.
To set the measurement system to correspond to your
machine’s leadscrews, complete the following steps for
each axis:
1. Turn the handwheel for each axis one full turn
clockwise. This assures that the software starts the
backlash compensation at the proper initial point.
2. Hold down the “Power” button for longer than a second
until the display changes.
3. Now you can set in the backlash for each axis by
pushing the button for that axis. Each time the button
is depressed, .0005" (or .01 mm on metric units) is
added to the reading. Set in the amount of backlash
you measured previously for each axis. Amounts up
to .015" (.50 mm) can be set. (Note: You cannot cycle
backwards to a lower number. If you go past your
desired setting you must continue pushing the button
until the reading passes .015" or .50 mm and returns
to zero. Then start over.)
4. Once the backlash for all three axes is set, briey push
the “Power” button again to return the display to its
normal reading. The backlash setting can be checked
or changed at any time by holding the power button
until the display changes. The amount can then be reset
as described in instruction number 3 above. Once set,
backlash settings are held in a special memory chip
even if the unit is turned off and unplugged. They
remain until you change them.
Adjusting the Z-axis Handwheel Screw
To adjust tension on the screw, rst remove all Z-axis
backlash in the conventional manner by lifting the motor/
speed control unit by hand while tightening the handwheel

P/N 8100, Pg. 5 of 7
set screw on a “fresh” quadrant of the leadscrew to avoid
picking up any previous indentations. Once adjusted, tighten
the center screw* only until it is “nger tight”. Use a very
small amount of Loc-tite®on the end of the screw to keep it
in place. (Do not coat the threads or the screw may become
impossible to remove.) Overtightening the screw will cause
the handwheel to become hard to turn. The purpose of the
screw is not to adjust backlash, but rather to keep it from
increasing once it is properly adjusted. Do not try to use
the screw to pull out additional backlash. The small 5-40
threads are not strong enough for this task.
*NOTE: If installing the Z-axis DRO handwheel on an
older machine that does not have a 5-40 hole in the end of
the leadscrew this screw is not used.
Tach Readout
In addition to the mode selections, the tach readout is also
different for our leadscrew machines and our ball screw
machines.
The leadscrew machines have a tach sticker that goes on
the headstock pulley. This is the tach sticker that comes
with the DRO. This tach sticker is a 6-pulse tach sticker. If
you have a leadscrew machine, use the 6-pulse tach sticker.
The ball screw machines come with the MASSO 5-pulse
tach sticker. This 5-pulse tach sticker is what the optical
encoder uses with the MASSO controller. Use the 5-pulse
tach sticker on the ball screw machine. When you set your
DRO to Mode 3 or Mode 6, the software is set up to read
the 5-pulse tach sticker.
You can also change the “Tach Pulse Number” on the DRO
to match either a 5 or 6-pulse tach sticker on your machine.
To do this, follow the previous instructions to set the DRO
to your machine and desired readout setting.
Then follow the instructions below to change the tach
pulse setting:
1. Disconnect the DC power from the DRO box.
2. Simultaneously hold down the Power, X, Y, and
Z buttons, and reconnect the DC power. This is
accomplished easiest by using your forenger to hold
down the X, Y, and Z buttons, and your pointer nger
to hold down the Power button.
3. When the DRO display screen comes on the “T6”
should change to a “T5” in this case.
NOTE: If you have a ball screw machine, and you are
using a controller other than our MASSO controller, you
will need to request the 5-pulse tach sticker (P/N 87860)
for the DRO tach readout to be correct.
A Few More Tips
When in use, shield the unit from chips so they don’t
accumulate around the telephone jack connections
on the side. Do not use an air hose to clean the unit.
A metal stand is included with your DRO so you can stand
the unit up on your workbench. This makes it easier to
read while you work. If you wish to secure the box to the
stand, a piece of double-sided foam tape or hook-and-loop
(Velcro®) tape are good methods.
Reversing the Direction of the Reading on the X-axis
The X-axis readout is designed to read negative numbers
when the handwheel is turned in the clockwise direction
and positive when turned counter-clockwise. Should you
wish to change your readout so that it uses a standard x-y
plot, you can do so by switching two of the four wires
coming from the encoder for the X-axis.
To do so, unplug the X-axis cable from the readout box.
Remove the four screws that secure the lower housing to
the upper housing and then remove the encoder halves from
the handwheel. On the bottom of the half with the encoder
is a cover plate secured by three screws. Remove these
screws and the cover plate. This will expose the soldered
connections for the four wires coming from the encoder.
To reverse the direction of the readout, unsolder the green
and black wires. Reverse their position and re-solder to the
encoder leads. Reinstall in reverse order. The diagram in
Figure 9 shows the factory locations of the wires before
the swap is made.
SINGLE HOLE
TO PLUG
TOP VIEW
GREEN
BLACK
G
Y R
BK
WIRING
DIAGRAM
FIGURE 9—The drawing on the left shows the encoder housing
and wires coming from the plug. The diagram to the right shows
a schematic of where each wire is connected. Swapping the black
and green wires will change the + (plus) and – (minus) directions
of the readout.
NOTE: The wires and solder joints are small and delicate.
If you don’t have a suitable soldering iron and a little
expertise along these lines you may return your encoder
housing to the factory and we will make the change for you
at no charge. Call rst for a return authorization number
and instructions on how to return your housing.
Getting the Most out of Your DRO
When using a machine equipped with a digital readout, we
nd it is best to use either the readout or the handwheels,
but not both. If the displayed accuracy of .0005" (.01mm)
is satisfactory for the job you are doing, use just the digital
readout and disregard the handwheel settings. In cases
where you might want to interpolate to a higher degree
of accuracy, the markings on the handwheels will allow
you to do this.
An example of this would be where you have located the
center of a bored hole and then changed the table position.
To return the spindle exactly to the hole’s center again using
the digital readout could leave you a few ten-thousandths

P/N 8100, Pg. 6 of 7
Mode Key
Combination
Leadscrew
Pitch
Displayed
Units
Example
Display
Position
Resolution
Backlash
Entry Units
Power Up
Display Notes
1 ON + X .05"/Turn Inch + 1.0055 .0005" Inch ININT6
Original Inch Mode for
a machine with an inch
leadscrew
2 ON + Y 1 mm/Turn Metric + 25.41 .01 mm mm M1MMT6
Original Metric Mode for
a machine with an metric
leadscrew
3 ON + Z 2 mm/Turn Inch + 0.3937 0.0008" mm M2INT5
For a Ball Screw machine
showing the readout in
inches
4ON + X + Y .05"/Turn Metric + 1.0055 .01 mm Inch INMMT6
For an Inch Leadscrew
machine showing the
readout in metric
5ON + Y + Z 1 mm/Turn Inch + 1.0055 0.0004" mm M1INT6
For a Metric Leadscrew
machine showing the
readout in inch
6ON + X + Z 2 mm/Turn Metric + 25.42 0.02 mm mm M2MMT5
For a Ball Screw machine
showing the readout in
metric
2021 DRO Mode Settings
NOTE: For more detailed information on setting up the modes for DRO, please see the DRO Mode Instructions
https://sherline.com/wp-content/uploads/2021/07/dro_mode_inst.pdf
off, which may not be acceptable. In this case, you should
write down your handwheel settings and direction the
handwheel was last turned before moving from the desired
location. This will allow you to return to the same spot
with great accuracy. The handwheel marks are .001" or
.01mm apart. By reading the space between the marks on
the handwheel and interpolating your position, you can
achieve a high degree of accuracy. Knowing your machine
is an important part of achieving this kind of accuracy, and
as you get more familiar with your machine, your accuracy
will continue to improve.
Sherline’s DRO brings modern machine shop technology
down to tabletop size and makes your Sherline tools easier
and more fun to use. We think you will nd the digital
readout to be a great addition to your Sherline machine shop.
Thank you,
Sherline Products Inc.

P/N 8100, Pg. 7 of 7
P/N 8100 Mill Digital Readout
2
14
4
5
6
7 (X- and Y-axes)
8 (Z-axis)
Cable
9
Sensors
12/12(a)
1
Asby. 3*
asby.
*Assembly includes housing,
sensors, cable and screws but
not handwheel and gear.
10
11
Assembly
Tach sensor
Cable
Sensor housing
13
* NOTE: The Z-axis handwheel has a hole through the center and comes with a 5-40 x 3/8" flat head screw that
goes into the end of the Z-axis leadscrew. The screw is P/N 45013.
REF.
NO.
PART
NO.
DESCRIPTION REF.
NO.
PART
NO.
DESCRIPTION
1 81010 3-axis DRO box and electronics (complete) 10 81270 2-56 x 3/8" pan head Phillips screw
2 81320 2" X-axis handwheel, inch (Metric 81322) 11 81500 Tachometer encoder & cable asby.
81330 2" Y-axis handwheel, inch (Metric 81332) 12 81510 6-pulse Tachometer pickup decal (standard
leadscrews)
81340 2.5" Z-axis handwheel, inch (Metric 81342) 12a 87860 5-pulse Tachometer pickup decal (ball screws)
3 81100 Encoder housing w/ wheel and cable 13 40440 #2 x 1/4” Self-tapping pan head screw
4 81110 Encoder housing upper cap 14 81310 Encoder star gear
5 81120 Encoder housing body -- 81080 Black tie-wrap (not shown)
6 81130 Encoder housing lower cap -- 81050 115 VAC Power supply/transformer(not shown)
7 81300 X- and Y-axis thrust collar -- 81150 Stand for readout display box (not shown)
8 81350 Z-axis thrust collar -- 45013 Z-axis handwheel support screw (not shown)
9 81280 #2 x 3/8” Self-tapping pan head screw
NOTE: Numbered items are complete parts or assemblies. Part
reference numbers shown within the assemblies are individual
components that make up the assembly. Some are not for sale
individually and do not have part numbers listed.
Exploded View and Parts Listing