Walter Meier (Manufacturing), Inc., warrants every product it sells. If one of our tools needs service or repair, one of our
Authorized Service Centers located throughout the United States can give you quick service. In most cases, any of these
Walter Meier Authorized Service Centers can authorize warranty repair, assist you in obtaining parts, or perform routine
maintenance and major repair on your JET® tools. For the name of an Authorized Service Center in your area call
1-800-274-6848.
MORE INFORMATION
Walter Meier is consistently adding new products to the line. For complete, up-to-date product information, check with your
local Walter Meier distributor, or visit waltermeier.com.
WARRANTY
JET products carry a limited warranty which varies in duration based upon the product (MW stands for Metalworking, WW
stands for Woodworking).
WHAT IS COVERED?
This warranty covers any defects in workmanship or materials subject to the exceptions stated below. Cutting tools,
abrasives and other consumables are excluded from warranty coverage.
WHO IS COVERED?
This warranty covers only the initial purchaser of the product.
WHAT IS THE PERIOD OF COVERAGE?
The general JET warranty lasts for the time period specified in the product literature of each product.
WHAT IS NOT COVERED?
Three Year, Five Year and Lifetime Warranties do not cover products used for industrial or educational purposes. Products
with Three Year, Five Year or Lifetime Warranties that are used for industrial or education purposes revert to a One Year
Warranty. This warranty does not cover defects due directly or indirectly to misuse, abuse, negligence or accidents, normal
wear-and-tear, improper repair or alterations, or lack of maintenance.
HOW TO GET SERVICE
The product or part must be returned for examination, postage prepaid, to a location designated by us. For the name of the
location nearest you, please call 1-800-274-6848.
You must provide proof of initial purchase date and an explanation of the complaint must accompany the merchandise. If
our inspection discloses a defect, we will repair or replace the product, or refund the purchase price, at our option. We will
return the repaired product or replacement at our expense unless it is determined by us that there is no defect, or that the
defect resulted from causes not within the scope of our warranty in which case we will, at your direction, dispose of or
return the product. In the event you choose to have the product returned, you will be responsible for the shipping and
handling costs of the return.
HOW STATE LAW APPLIES
This warranty gives you specific legal rights; you may also have other rights which vary from state to state.
LIMITATIONS ON THIS WARRANTY
WALTER MEIER (MANUFACTURING), INC., LIMITS ALL IMPLIED WARRANTIES TO THE PERIOD OF THE LIMITED
WARRANTY FOR EACH PRODUCT. EXCEPT AS STATED HEREIN, ANY IMPLIED WARRANTIES OR MERCHANTABILITY
AND FITNESS ARE EXCLUDED. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG THE IMPLIED WARRANTY
LASTS, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU.
WALTER MEIER SHALL IN NO EVENT BE LIABLE FOR DEATH, INJURIES TO PERSONS OR PROPERTY, OR FOR
INCIDENTAL, CONTINGENT, SPECIAL, OR CONSEQUENTIAL DAMAGES ARISING FROM THE USE OF OUR PRODUCTS.
SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES, SO
THE ABOVE LIMITATION OR EXCLUSION MAY NOT APPLY TO YOU.
Walter Meier sells through distributors only. The specifications in Walter Meier catalogs are given as general information
and are not binding. Members of Walter Meier reserve the right to effect at any time, without prior notice, those alterations
to parts, fittings, and accessory equipment which they may deem necessary for any reason whatsoever. JET® branded
products are not sold in Canada by Walter Meier.
The JETModel J-4210 Belt and Disc Sanding Machine
is ideal for all shops. This versatile machine can be
used to grind, sand, finish, and contour all types of
parts including metal, wood, plastic, and composite
materials. Because of these capabilities, the JET
sander eliminates the need for multiple machines to
perform the same tasks.
Specifications
Model No.J-4210
Stock No.414550
Belt Size6" x 48"
Disc Size10"
Motor
Horsepower1 HP
Voltage115/230 Vac (pre-wired for
115 Vac)
SwitchRemovable Safety Key
PlatenCast Iron
TablesCast Iron (2)
Belt Speed1650 SFPM
Disc Speed2100 RPM
Dust Collection Shrouds Two (standard)
Weight120 lbs.
3
JET Belt/Disc Sander, Model J-4210
Page 4
plugging in machine.
When using machine:
- Never operate with machine guards missing.
General Machinery Cautions
- Misuse of this machine can cause serious injury.
- For safety, machine must be set up, used and
serviced properly.
- Read, understand and follow instructions in the
operator’s and parts manual which was shipped with
your machine.
When setting up machine:
- Always avoid using machine in damp or poorly
lighted work areas.
- Always be sure machine is securely anchored to
the floor.
- Always keep machine guards in place.
- Always put start switch in “OFF” position before
You — the stationary power tool user — hold the key to safety.
Read and follow these simple rules for best results and full benefits from your machine. Used properly, JET
machinery is among the best in design and safety. However, any machine used improperly can be rendered
inefficient and unsafe. It is absolutely mandatory that those who use our products be properly trained in how to
use them correctly. They should read and understand the Operators and Parts Manual as well as all labels
affixed to the machine. Failure in following all of these warnings can cause serious injuries.
- Always wear safety glasses with side shields (See
ANSI Z87.1)
- Never wear loose clothing or jewelry.
- Never overreach — you may slip and fall into the
machine.
- Never leave machine running while you are away
from it.
- Always shut off the machine when not in use.
When servicing machine:
- Always unplug machine from electrical power while
servicing.
- Always follow instructions in operators and parts
manual when changing accessory tools or parts.
- Never modify the machine without consulting Walter
Meier (Manufacturing) Inc.
Machinery general safety warnings
1.Always wear protective eye wear when operating
machinery. Also use face or dust mask if cutting
operation is dusty. Everyday eyeglasses only
have impact resistant lenses, they are NOT
safety glasses. Eye wear shall be impact resistant, protective safety glasses with side shields
which comply with ANSI Z87.1 specifications.
Use of eye wear which does not comply with
ANSI Z87.1 specifications could result in severe
injury from breakage of eye protection.
2.Wear proper apparel. Do not wear loose clothing,
gloves, neckties, rings, bracelets, or other jewelry
4
which may get caught in moving parts. Nonslip
footwear is recommended. Wear protective hair
covering to contain long hair.
3.Do not overreach. Keep proper footing and
balance at all times. Failure to maintain proper
working position can cause you to fall into the
machine or cause your clothing to get caught —
pulling you into the machine.
4.Keep guards in place and in proper working order.
Do not operate the machine with guards removed.
5.Don't use in dangerous environment. Don’t use
power tools in damp or wet locations, or expose
them to rain. Keep work area well lighted.
6.Reduce the risk of unintentional starting. Make
sure switch is in off position before plugging in.
7.Never leave the machine running while unattended. Don't leave machine until it comes to a
complete stop.
8.Disconnect tools before servicing; when changing
accessories, such as blades, bits, cutters, and
the like. Whenever changing accessories or
general maintenance is done on the machine,
electrical power to the machine must be disconnected before work is done.
9.Maintain all machine tools with care. Keep tools
sharp and clean for best and safest performance.
Follow all maintenance instructions for lubricating
and the changing of accessories. No attempt
shall be made to modify or have makeshift repairs
done to the machine. This not only voids the
warranty but also renders the machine unsafe.
10. Machinery must be anchored to the floor.
11. Secure work. Use clamps or a vise to hold work,
when practical. It’s safer than using your hand
and it frees both hands to operate tool.
12. Never brush away chips while the machine is in
operation.
13. Keep work area clean. Cluttered areas invite
accidents.
14. Remove adjusting keys and wrenches before
turning machine on. Form habit of checking to
see that keys and adjusting wrenches are
removed from tool before turning it on.
15. Use the right tool. Don’t force a tool or attachment to do a job it was not designed for.
16. Use recommended accessories. Consult the
owner’s manual for recommended accessories.
The use of improper accessories may cause risk
of injury to persons.
Page 5
17. Keep hands in sight and clear of all moving parts
and cutting surfaces.
18. All visitors should be kept at a safe distance from
the work area. Make workshop completely safe
by using padlocks, master switches, or by
removing starter keys.
19. Know the tool you are using — its application,
limitations, and potential hazards.
20. Keep children away. All visitors should be kept
safe distance from work area.
21. Make workshops kidproof with padlocks, master
switches, or by removing starter keys.
22. Don't force tool. It will do the job better and safer
at the rate for which it was designed.
23. Never stand on tool. Serious injury could occur if
the tool is tipped or if the cutting tool is unintentionally contacted.
24. Check damaged parts. Before further use of the
tool, a guard or other part that is damaged should
be carefully checked to determine that it will
operate properly and perform its intended function
- check for alignment of moving parts, binding of
moving parts, breakage of parts, mounting, and
any other conditions that may affect its operation.
A guard or other part that is damaged should be
properly repaired or replaced.
25. Direction of feed - Feed work into a blade or
cutter against the direction of rotation of the blade
or cutter only.
26. Never leave tool running unattended. Turn power
off. Don’t leave tool until it comes to a complete
stop.
Grounding Instructions
1. All grounded, cord-connected tools:
In the event of a malfunction or breakdown, grounding
provides a path of least resistance for electric current
to reduce the risk of electric shock. This tool is
equipped with an electric cord having an equipmentgrounding conductor and a grounding plug. The plug
must be plugged into a matching outlet that is
properly installed and grounded in accordance with all
local codes and ordinances.
Do not modify the plug provided - if it will not fit the
outlet, have the proper outlet installed by a qualified
electrician.
Improper connection of the equipment-grounding
conductor can result in a risk of electric shock. The
conductor with insulation having an outer surface that
is green with or without yellow stripes is the equipment-grounding conductor. If repair or replacement of
the electric cord or plug is necessary, do not connect
the equipment-grounding conductor to a live terminal.
Check with a qualified electrician or service personnel
if the grounding instructions are not completely
understood, or if in doubt as to whether the tool is
properly grounded.
Use only 3-wire extension cords that have 3-prong
grounding plugs and 3-pole receptacles that accept
the tool’s plug.
Repair or replace damaged or worn cord immediately.
General Electrical Cautions
This machine should be grounded in accordance with
the National Electrical Code and local codes and
ordinances. This work should be done by a qualified
electrician. The machine should be grounded to
protect the user from electrical shock.
Wire sizes
Caution: for circuits which are far away from the
electrical service box, the wire size must be increased in order to deliver ample voltage to the motor.
To minimize power losses and to prevent motor
overheating and burnout, the use of wire sizes for
branch circuits or electrical extension cords according to the following table is recommended:
Ampere Rating 120V 25 ft50 ft100 ft150 ft
MoreNot more
Volts Total length of cord in feet
240V 50 ft100 ft200 ft300 ft
5
Figure A
2. Grounded, cord-connected tools intended for
use on a supply circuit with a nominal rating less
than 150 V:
This tool is intended for use on a circuit that has an
outlet that looks like the one illustrated in Sketch A in
Figure A. The tool has a grounding plug that looks like
the plug illustrated in Sketch A in Figure A. A temporary adapter, which looks like the adapter illustrated in
Sketches B and C, may be used to connect this plug
to a 2-pole receptacle as shown in Sketch B if a
properly grounded outlet is not available.
Page 6
The temporary adapter should be used only until a
properly grounded outlet can be installed by a qualified electrician. The green-colored rigid ear, lug, and
the like, extending from the adapter must be connected to a permanent ground such as a properly
grounded outlet box.
3. Grounded, cord-connected tools intended for
use on a supply circuit having a nominal rating
between 150 - 250 V, inclusive:
This tool is intended for use on a circuit that has an
outlet that looks like the one illustrated in Sketch D in
Figure A. The tool has a grounding plug that looks like
the plug illustrated in Sketch D in Figure A. Make
sure the tool is connected to an outlet having the
same configuration as the plug. No adapter is avail-
able or should be used with this tool. If the tool must
be reconnected for use on a different type of electric
circuit, the reconnection should be made by qualified
service personnel; and after reconnection, the tool
should comply with all local codes and ordinances.
4. Permanently connected tools - This tool should
be connected to a grounded metal permanent wiring
system; or to a system having an equipment-grounding conductor.
5. Polarized Plugs - To reduce the risk of electric
shock, this equipment has a polarized plug (one blade
is wider than the other). This plug will fit in a polarized
outlet only one way. If the plug does not fit fully in the
outlet, reverse the plug. If it still does not fit, contact a
qualified electrician to install the proper outlet. Do not
change the plug in any way.
Safety Requirements for Abrasive Sanding Machines
Abrasive sanding can be hazardous to operators and
bystanders. Sanding sparks, chips and dust particles
thrown off by the sanding disc can cause serious
injury by contact or inhalation. To avoid injuries you
must comply with the following safety requirements:
1. Always wear protective eyewear when operating
machinery. Eye wear shall be impact resistant,
protective safety glasses with side shields which
comply with ANSI Z87.1. Use of eye wear which
does not comply with ANSI Z87.1 specifications could
result in severe injury from breakage of eye protection. See Figure B, below.
2. Wear leather safety gloves, arm guards, leather
aprons and safety shoes.
3. A dust collection system is recommended,
Operator shall also wear a dust mask at all times.
See Figure C, below.
4. Additional precautions may be necessary for
sanding materials which are flammable or have other
6
hazardous properties. You should always consult the
manufacturer of such materials for instructions on
sanding and handling.
5. Do not force or jamb the workpiece into the
sanding disc.
6. Before sanding, always allow the motor to come
up to operating speed, then check the sanding disc
for wobble, runout, or any unbalanced condition. If
the disc is not operating accurately and smoothly,
immediately stop the motor and make repairs before
attempting any sanding operations.
7. Abrasive discs must be stored in a controlled
environment area. Relative humidity should be 35%
to 50% and the temperature should be between 60
and 80 degrees Farenheit. Failure to do so could
cause premature disc failure.
8. Examine the face of the sanding disc carefully.
Excessive sanding which wears down to the backing
material can tearing of the disc. Never use a disc
which shows backing, nicks or cuts on the surface or
edge or damage due to creasing or poor handling.
9. When installing a new disc, be certain the disc is
accurately centered on the drive wheel. Failure to do
so could cause a serious unbalanced condition.
10. Always present the workpiece to the wheel while
resting the workpiece firmly on the table. Failure to
do so could result in damage to the workpiece or
throwing of the workpiece off the wheel.
11. Safety shoes which comply with ANSI Z41.1 shall
be worn. See Figure D.
12. Personal hearing protection such as ear plugs or
ear muffs shall be used to protect against the effect of
noise exposure. See Figure E.
Figure B Figure C Figure D Figure E
Page 7
Introduction
This manual includes operating and maintenance
instructions for the JET Model J-4210 Belt and Disc
Sander. This manual also includes parts listings and
illustrations of replaceable parts.
Belt and Disc Sander
Features
Figures 1 and 2 depict the main features of the JET
Model J-4210 Belt and Disc Sander. (Specifications
for the sanding machine are provided on page 3.)
Tracking Adjustment
Belt Tensioning Lever
Belt Work Table
Clamping Knob
Sanding Belt
Belt Guard
Platen Housing
Debris Duct
On/Off
Switch
Belt Sander
Work Table
Machine
Base
Stand
Sanding Disk
Disc
Debris
Duct
Miter Gauge
Disc Work Table
Clamping Knob
Figure 1: Belt and Disc Sander Features
(Right Side View)
Power Cord
Figure 2: Belt and Disc Sander Features
(Left Side View)
The sander has both a sanding belt and a sanding
disc for use on a variety of work pieces and materials.
The platen housing for the belt sander can be positioned vertically or horizontally. When in the vertical
position, the drum at the upper end of the platen
housing can be used for contouring. A tracking
adjustment mechanism for the sanding belt is provided at the upper end of the platen housing.
The platen housing has a lever that is used to apply
tension to the sanding belt. The sanding belt is easily
replaced by releasing the tension lever, removing a
sanding shroud and dust collection duct at the bottom
of the platen housing, and slipping the belt from the
belt sander drums. Installation is the reverse of the
removal steps.
7
Page 8
The disc sander consists of an aluminum disc onto
which is installed an adhesive-backed sanding and
other abrasive discs. The disc is contained within a
ducted shroud.
The sanding disc can be replaced by removing the
table and a cover over the lower portion of the disc.
If desired, the aluminum disc can be removed from
its drive shaft to ease replacement of the sanding
disc.
The drive motor for the belt and disc sander is
attached to the underside of the machine base. An
ON/OFF switch is mounted on the machine base on
the side opposite the disc sander. Electrical wiring
for the motor enters the machine base below the ON/
OFF switch and is routed to the switch and motor
inside the machine base.
The belt and disc sander is driven by V-belts connected to the drive motor. A pulley on the motor shaft
drives a V-belt that drives a dual-groove pulley on an
idler shaft. A second V-belt is installed in the second
groove of the dual-groove pulley and connects to a
pulley on belt sander drive shaft.
Installation and Setup
Mounting
It is recommended that the belt and disc sander be
secured to the floor for safe operation. The machine
stand has mounting holes in a flange on the inside of
stand enclosure. The stand can be secured to the
floor using these mounting holes.
Electrical Connection
Refer to the Wiring Data section for wiring information. Electrical power should be connected by a
qualified electrician. Observe local electrical codes
when connecting and grounding the machine.
The aluminum sanding disc is driven off the end of
the idler shaft. A shaft connected to the second Vbelt pulley drives the belt sander drive drum.
The belt and disc sander is mounted on a stand that
can be secured to the floor to stabilize the machine.
The stand has a door for access to the fasteners for
the machine base.
8
Page 9
Operation
This section defines the controls and other features
with which the operator should be familiar. Refer to
Figures 3 and 4 for some typical sander operations.
Figure 3. Contouring with Belt Sander
Figure 5. ON/OFF Switch
Miter Gauge
A miter gauge is provided with the machine and can
be used on either the belt sander of disc sander work
tables. The angle of the miter gauge can be adjusted
up to 45 degrees to accommodate angular work
piece surfaces.
Adjustments
Adjusting Belt Tracking
The tracking of the sanding belt may require adjustment after changing the belt. The belt housing has a
tracking adjustment mechanism (Figure 6) that is
used to adjust tracking.
Figure 4. Sanding using Disc Sander
Controls
The ON/OFF switch is located on the side of the
machine base (refer to Figure 5).
1.Start the machine.
2.Check tracking of the sanding belt. The belt
should track at the center of the drums.
3.Adjust belt tracking by turning the adjustment
knob. Turn the knob as needed to correct the
tracking of the belt.
Belt should track
at center of drums;
no side-to-side
movement.
Belt Tracking
Adjustment Knob
Belt Tensioning
Lever
9
Figure 6. Adjusting Belt Tracking
Page 10
Adjusting Platen Housing
Adjusting the Sander Tables
Position
The sanding belt can be operated with the platen
housing horizontal, vertical, or at any angle in
between. Change position of the platen housing as
follows:
WARNING: DISCONNECT ELECTRICAL POWER
TO THE MACHINE BEFORE PERFORMING ANY
MAINTENANCE.
1.Disconnect electrical power.
2.Remove four screws (52) and pulley cover (12).
3.Using an open end wrench, loosen two hex
screws (13) (refer to Figure 7).
4.Move the platen housing to the desired position.
When the platen housing is to be placed in the
horizontal position, lower the platen housing onto
stop screw (28) on the machine base.
5.If the stop requires adjustment, loosen jam nut
(29), adjust stop screw (28) to desired position,
and tighten nut (29).
6.Tighten two hex screws (13).
7.Install pulley cover (12) and secure with four
screws (52).
8.Start the machine to check operation.
The belt and disc sander tables can be adjusted
from 0 to 45 degrees to accommodate the work
piece.
Disc Table
1.To change the disc table angle, loosen the knob
on the left side of the table (refer to Figure 8).
2.Move the table to the desired angle.
3.Tighten the knob to secure the table.
Belt Table
Clamping Knob
Belt Table Angle Scale
(left underside of table)
10
Clamping
Screws
Platen
Housing
Figure 7. Platen Housing Clamping Screws
Disc Table Angle Scale
Table Clamping Knob
Figure 8. Adjusting Sander Table Angle
Belt Table
1.To change the belt table angle, loosen the knob
on the right side of the platen housing (refer to
Figure 8).
2.Move the table to the desired angle.
3.Tighten the knob to secure the table.
Page 11
Maintenance
This section provides procedures required to maintain the belt/disc sander. The numbers in parentheses throughout the manual correspond with reference
numbers for parts shown in the exploded views in the
Replacement Parts section.
Lubrication
The bearings used in the sanding machine are
sealed, pre-lubricated bearing. The bearings do not
require periodic lubrication.
1.Install replacement sanding belt on drums.
Position edges of sanding belt evenly on the
drums.
2.Lift tensioning lever to tighten sanding belt on
drums.
3.Install guard (75) and secure with screw (76).
4.Install guard (96) and secure with eight screws
(97).
5.Connect electrical power and operate machine to
check operation.
6.If belt does not track properly, adjust tracking
(refer to Adjusting Belt Tracking).
Replacing the Sanding Disc
Cleaning
Periodically use a vacuum cleaner to remove sanding
debris from the machine. In hard to reach areas,
brush the debris loose while vacuuming.
Replacing the Sanding Belt
WARNING: DISCONNECT ELECTRICAL POWER
TO THE MACHINE BEFORE PERFORMING ANY
MAINTENANCE.
1.Disconnect electrical power.
2.Position sanding belt platen (4) in the vertical
position. Remove eight screws (97) and guard
(96).
3.Remove screw (76) and guard (75).
4.Move tensioning lever (50) downward to slacken
sanding belt (79).
Refer to Figure 9. Slip sanding belt off drums (5) and
(39).
WARNING: DISCONNECT ELECTRICAL POWER
TO THE MACHINE BEFORE PERFORMING ANY
MAINTENANCE.
1.Disconnect electrical power.
2.Loosen screw (65). Remove disc table (60).
3.Remove four screws (56) and plate (55) from
disc shroud (53).
4.Insert a long T-handle Allen wrench through the
side opening in shroud (53) and into set screw
(57). Loosen disc set screw (57) and remove
disc (58).
WARNING: USE CARE WHEN USING KNIFE TO
SEPARATE SANDING DISC (59) FROM DISC (58).
INJURY FROM THE KNIFE MAY OCCUR IF THE
KNIFE SLIPS OR IF SANDING DISC SHOULD
SUDDENLY COME FREE.
5.Using a knife, slowly work the tip of the knife
blade under sanding disc (59). Slowly work the
tip around the circumference of disc (58).
Continue to work around the circumference until
sanding disc can be separated by hand from
disc (58).
6.Remove paper backing from replacement sanding disc (59). Place sanding disc (59) on disc
(58). Make sure the sanding disc is place evenly
at the outside diameter of disc (58).
7.Press on the sanding disc to remove any entrapped air and to make sure the sanding disc is
adhering to disc (58).
8.Install disc (58) onto shaft (16). Position the disc
on the shaft to provide clearance between plate
(55) and sanding disc. Tighten set screw (57).
11
Figure 9. Replacing Sanding Belt
NOTE: There is a close fit between the edge of disc
(58) and disc shroud. To ease installation and positioning of the disc, use an L-shaped tool (such as an
Allen wrench) under outer edge of the disc to support
and position the disc while tightening set screw.
Page 12
9.Install plate (55) and secure with four screws (56).
Check for clearance between plate (55) and the
sanding disc.
10. Install table (60) onto rod (74). Position table so
it is level and tighten screw (65) against rod (74).
11. Connect electrical power and operate machine to
check operation.
Replacing the V-Belts
19. Install key in idler shaft with keyway facing up.
Install pulley (20) on idler shaft.
20. Install motor V-belt (18) in outermost groove of
pulley (20) and on pulley (18) on motor shaft.
21. Position motor belt (18) on idler shaft so it is
parallel with the inner wall of the base. Tighten
set screw in pulley (20).
22. Place assembled base on stand. Secure with
four screws, washers, nuts.
12
WARNING: DISCONNECT ELECTRICAL POWER
TO THE MACHINE BEFORE PERFORMING ANY
MAINTENANCE.
1.Disconnect electrical power.
2.Remove sanding belt table.
3.Remove sanding disc table.
4.Remove sanding disc and shroud.
5.Remove pulley cover. Loosen set screw in pulley.
6.With second person holding belt housing,
alternately loosen and remove two screws.
7.Remove V-belt from pulley (11). Remove pulley
from shaft while separating assembled belt
housing from the machine base.
8.Remove key from sanding belt drum shaft.
9.Loosen set screw in pulley (20).
10. Remove pulley. While removing pulley, slip Vbelts from pulley.
11. Remove four screws from base. With assistance
of the second person, lift base from stand.
NOTE: Place base on bench. As an alternative, the
stand may be used to support the base while removing drive motor screws.
12. Place base on bench with underside of the base
facing up.
13. Remove two hex head screws, two nuts, and two
washers from the motor base on the shaft side of
motor.
14. Loosen (but do not remove) two hex bolts, two
nuts, and two washers on the side of motor base
opposite the motor shaft.
15. Tip motor enough to provide clearance between
end of shaft and wall of base. Remove motor
drive belt.
16. With base still on the bench, slip V-belt (15) over
end of idler shaft.
NOTE: Install V-belt for sanding belt first, followed by
the motor V-belt.
17. Install replacement V-belt over end of motor shaft.
18. Install two hex bolts, two nuts, and two washers in
the motor base on the shaft side of motor.
Tighten all four hex nuts and hex head screws.
NOTE: Because of the weight of the belt housing, a
second person should hold the belt housing in
position while installing pulley (10).
23. Hold belt housing in position in bracket (3). Start
two screws (13) in threaded holes in platen.
Install key (8) in shaft.
NOTE: Because of the length of screws (13), the
screws will have to be installed alternately. As the
screws are installed, there will be enough clearance
to slide the belt drum drive pulley a little at a time onto
shaft (8).
24. Alternately install two screws (13). As the screws
are tightened, slide pulley (10) onto the idler shaft
as allowed by the protrusion of screw heads.
Make sure V-belt remains on pulleys (11 and 20).
25. When screws (13) are fully installed, align pulley
(20) with pulley (11). Tighten set screw (10).
26. Install shroud (53) on base and secure with four
screws and washers.
27. Install pulley cover (12) and secure with two
screws.
28. Install disc (58) onto shaft (16) and over key.
Position the disc on the shaft to provide clearance between plate (55) and the sanding disc.
Using long T-handle Allen wrench, tighten set
screw (57).
NOTE: There is a close fit between the edge of disc
(58) and the disc shroud. To ease installation and
positioning of the disc, use an L-shaped tool (such as
an Allen wrench) under the outer edge of the disc to
support and position the disc while tightening the set
screw.
29. Install plate (55) and secure with four screws
(56). Check for clearance between plate (55)
and the sanding disc.
30. Install table (60) onto rod (74). Position table so
it is level and tighten screw (65) against rod (74).
31. Install assembled table (88).
32. Connect electrical power and operate machine to
check operation.
Page 13
Replacement of Motor
WARNING: DISCONNECT ELECTRICAL POWER
TO THE MACHINE BEFORE PERFORMING ANY
MAINTENANCE.
1.Disconnect electrical power.
2.Remove four screws from base. With assistance
of the second person, lift base from stand.
NOTE: Place base on bench. As an alternative, the
stand may be used to support the base while removing drive motor screws.
3.Place base on bench with underside of the base
facing up.
4.Remove four hex head screws, nuts, and washers from the motor base.
5.Remove motor V-belt from motor pulley.
6.Remove motor from base.
7.Loosen set screw in pulley (18). Remove pulley.
8.Align set screw in pulley with flat on motor shaft
and install pulley. Do not tighten set screw.
9.Install replacement V-belt over end of motor shaft
and install motor in base . Secure with four
screws, washers and nuts.
10. Install and tighten four hex bolts, nuts, and
washers in the motor base.
11. Position pulley (18) on motor shaft so the V-belt
is parallel with the inner wall of the base. Tighten
set screw in pulley (20) against flat on motor
shaft.
12. Place assembled base on stand. Secure with
four screws, washers, nuts.
13. Connect electrical power and operate machine to
check operation.
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Page 14
Wiring Data
Single phase electrical hook-up
Note: Local electrical codes in many jurisdictions do
not allow the use of plug type connections for single
phase power when the machine is used in a commercial or industrial establishment.
When connecting your machine to single phase
power you may be connecting to either 115 or 230
volts, depending upon the motor type provided. Local
codes may, or may not, permit the use of a plug type
of connection for your machine. Where a plug
connection is permitted, the following installation
practices must be followed:
1. The plug used must be a grounding type of plug.
On a 115 volt single phase connection, the plug
must be a three-prong plug with two flat, parallel
blades for the power wires and a single rounded
or U-shaped prong for the ground connection.
On 230 volt single phase connections, the lug
must be a three prong plug with two flat blades in
tandem to carry the current, and a third round or
U-shaped prong for the ground connection.
2. The service branch to which the plug is connected
must be a branch with a separate ground wire so
the grounding prong of the plug can be connected to ground effectively.
In these cases you must connect your machine to
the service branch using a hard-wired junction box
connection.
All JET sanders are shipped with the power cable
terminating without a plug on the assumption the
machine will be hard-wired to its service branch.
Circuit protection
Where the service branch is protected with a fuse or
circuit breaker which is too high a value to offer
protection to the motor supplied, a fuse or circuit
breaker box should be used at the point where the
machine connection is made and the time delay fuse
or circuit breaker should be a value just slightly
higher than the maximum load current draw as
specified on the motor plate on the motor.
Correcting motor rotation in single
phase motors
JET provides single phase motors in both 115 volt and
230 volt configuration. Several motor manufactures
may be used by JET for motors of this type.
14
Figure 10: Pictoral diagram for single
phase motor, 115 volts w/plug.
Figure 11: Pictoral diagram for
3-phase motor.
These motors may, or may not, rotate in the correct
direction -- counter-clockwise -- when connected to
your single phase power source. If, after connection, the motor runs in the correct counter-clockwise
direction, the power connection is successful.
CAUTION: IF THE MOTOR RUNS CLOCKWISE
WHEN CONNECTED TO YOUR SINGLE PHASE
POWER SOURCE, YOU MUST DISCONNECT THE
POWER SOURCE, OPEN THE JUNCTION BOX
AND FIND THE CORRECT WIRING CONNECTIONS
FOR THE MOTOR, OR LOCATE THE WIRING
CONNECTIONS REQUIRED ON THE MOTOR PLATE
ON THE OUTSIDE OF THE MOTOR.
Different manufacturers provide different wiring
configurations for correcting the rotation of the motor
armature. Therefore, no wiring diagrams for these
motors are provided in this manual. Always consult
the motor plate and/or the wiring diagram inside the
junction box if rotation direction is not correct.
Page 15
Connecting Power for 3-phase Motors
1. Be certain the power to the branch you are
connecting is off, and locked out, so power
cannot be reestablished, accidentally.
2. Connect the ground wires. Thse wires will be
either green, or green with a white trace.
3. Connect the remaining three cable wires to the
three power wires in the service branch.
4. Reestablish power to the branch.
5. Turn the machine on. The motor should be
turning counter-clockwise, the belt sander should
be moving downward, and the disc sander should
be turning clockwise. If this is the case, the
machine can be considered wired correctly. If
the motor is not turning in the correct direction,
take the following corrective action:
6. Disconnect power in the branch again and be
certain it cannot be accidentally turned on while
you correct the wiring.
7. Reverse ANY TWO of the power wires to the
machine.
8. Reestablish power in the service branch to the
machine.
9. Turn on the machine again. The motor should
now be turning in the correct direction.
Figure 12: Schematic diagram for
single phase motor with 3-wire
cable. Note: this schematic
provided for use with older
sanders, only. All machines are
now shipped with a 4-wire cable
whether single phase or 3-phase.
Figure 13: Schematic diagram for
single phase motor with 4-wire
cable.
Figure 14: Schematic diagram for
3-phase motor.
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Page 16
Troubleshooting
FaultProbable Cause Remedy
Machine does not start.1. Blown fuse or tripped1. Determine reason for blown fuse/tripped
circuit breaker.breaker (such as a short circuit or motor
overload). Correct reason for fault. Replace
fuse/reset breaker.
2. Motor failure.2. Replace motor.
3. Not connected to power3. Connect to power source.
source.
4.Motor not wired for correct4. Correct motor wiring.
voltage.
5. Motor not connected to5. Connect to proper voltage source.
correct voltage source.
Sanding belt does not1. Sanding belt stretched1. Replace sanding belt.
trackcorrectly.unevenly.
2. V-belt worn.2. Replace V-belt.
3. Pulley worn.3. Replace pulley.
Abrasive disc separates1. Improperly bonded.1. Clean residual adhesive from disc.
from disc.Reapply adhesive-backed disc to clean disc.
16
Sanding belt slips or stalls1. Abrasive belt tension1. Tighten sanding belt.
when pressure is applied.inadequate.
2. Excessive pressure being2. Reduce pressure on sanding belt
applied to platen housing.(and platen housing).
3. Motor belt loose.3. Tighten motor belt.
Disc stalls when pressure1. Motor V-belt loose.1. Tighten motor V-belt.
is applied.
Frequent replacement of1. Too much pressure being1. Reduce pressure on work piece.
sanding belt.applied to work piece.
2. Full width of belt not being2. Stroke across sanding belt using full width
used.of belt surface.
Page 17
Replacement Parts
This section provides exploded view illustrations that show the replacement parts for the JET Model J-4210 Belt/
Disc Sander. Also provided are parts listings that provide part number and description. The item numbers
shown on the illustration relate the item number in the facing parts listing.
Order replacement parts from:
WALTER MEIER (Manufacturing) Inc.
427 New Sanford Road
LaVergne, Tennessee 37086
Ph.: 800-274-6848
www.waltermeier.com
To order parts or reach our service department, call 1-800-274-6848 Monday through Friday (see our website for
business hours, www.waltermeier.com). Having the Model Number and Serial Number of your machine available
when you call will allow us to serve you quickly and accurately.
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Page 18
Assembled View and Parts Listing of Stand –
Model J-4210 Belt and Disc Sander