JET 577011, 577010 User Manual

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Operating Instructions and Parts Manual

20-inch Disc Grinder

Models J-4421-2 and J-4421-4

JET

1.0 Warranty and Service

JET warrants every product it sells against manufacturers’ defects. If one of our tools needs service or repair, please contact Technical Service by calling 1-800-274-6846, 8AM to 5PM CST, Monday through Friday.

Warranty Period The general warranty lasts for the time period specified in the literature included with your product or on the official JET branded website.

• JET products carry a limited warranty which varies in duration based upon the product. (See chart below)

• Accessories carry a limited warranty of one year from the date of receipt.

• Consumable items are defined as expendable parts or accessories expected to become inoperable within a

reasonable amount of use and are covered by a 90 day limited warranty against manufacturer’s defects.

Who is Covered

This warranty covers only the initial purchaser of the product from the date of delivery.

What is Co vered

This warranty covers any defects in workmanship or materials subject to the limitations stated below. This warranty does not cover failures due directly or indirectly to misuse, abuse, negligence or accidents, normal wear-and-tear, improper repair, alterations or lack of maintenance.

Warranty Limitations

Woodworking products with a Five Year Warranty that are used for commercial or industrial purposes default to a Two Year Warranty. Please contact Technical Service at 1-800-274-6846 for further clarification.

How to Get Technical Support Please contact Technical Service by calling 1-800-274-6846. Please note that you will be asked to provide proof of initia l p u rch a s e whe n calling. If a product requires further inspection, the Technical Service representative will

explain and assist with any additional action needed. JET has Authorized Service Centers located throughout the United States. For the name of an Authorized Service Center in your area call 1-800-274-6846 or use the Service Center Locator on the JET website.

More Informa tion

JET is constantly adding new products. For complete, up-to-date product information, check with your local distributor or visit the JET website.

How S tate Law A pplies

This warranty gives you specific legal rights, subject to applicable state law.

Limitations on This Warranty

JET LIMITS ALL IMPLIED WARRANTIES TO THE PERIOD OF THE LIMITED WARRANTY FOR EACH PRODUCT. EXCEPT AS STATED HEREIN, ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXCLUDED. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE LIMITATION MAY NOT APPLY TO YOU.

JET 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.

JET sells through distributors only. The specifications listed in JET printed materials and on official JET website are given as general information and are not binding. JET reserves 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

Product Listing with Warranty Period

90 Days – Parts; Consumable items; Light-Duty Air Tools 1 Year – Motors; Machine Accessories; Heavy-Duty Air Tools; Pro-Duty Air Tools 2 Year – Metalworking Machinery; Electric Hoists, Electric Hoist Accessories; Woodworking Machinery used for industrial or commercial purposes 5 Year – Woodworking Machinery Limited Lifetime – JET Parallel clamps; VOLT Series Electric Hoists; Manual Hoists; Manual Hoist Accessories; Shop Tools; Warehouse & Dock products; Hand Tools

NOTE: JET is a division of JPW Industries, Inc. References in this document to JET also apply to JPW Industries, Inc., or any of its successors in interest to the JET brand.

branded products are not sold in Canada by JPW Industries, Inc.

2.0 Table of contents

Section Page

1.0 Warranty and Service ..................................................................................................................................... 2

2.0 Table of contents ............................................................................................................................................ 3

3.0 Warnings ........................................................................................................................................................ 4

3.1 Machinery General Safety Warnings .......................................................................................................... 4

3.2 General Electrical Cautions ........................................................................................................................ 2

3.3 Wire Sizes .................................................................................................................................................. 2

3.4 Safety requirements for abrasive grinding machines ................................................................................. 2

4.0 General Specifications ................................................................................................................................... 6

5.0 Machine set-up ............................................................................................................................................... 7

5.1 Grinder set-up ............................................................................................................................................ 7

5.2 Spotting and anchoring the sander ............................................................................................................ 7

5.3 Checking table level ................................................................................................................................... 7

6.0 Electrical ......................................................................................................................................................... 7

6.1 Service wiring ............................................................................................................................................. 7

6.2 To correct disc rotation ............................................................................................................................... 8

6.3 Changing service voltage ........................................................................................................................... 8

6.4 Replacing the LVP switch cut-out coil ........................................................................................................ 8

6.5 Changing motor connections ...................................................................................................................... 8

7.0 Operating Instructions .................................................................................................................................... 9

7.1 Applying a workpiece to the disc face ........................................................................................................ 9

7.2 ON/OFF Switch .......................................................................................................................................... 9

7.3 Raising and lowering the table ................................................................................................................. 10

7.4 Adjusting the table angle .......................................................................................................................... 10

7.5 Using the miter system ............................................................................................................................. 11

8.0 Recomm en de d abra siv es

9.0 Maintenan ce pro ce dur es

9.1 Removing and replacing grinding discs .................................................................................................... 12

9.2 Removing and replacing motor and/or drive disc ........................................................................... .......... 13

10.0 Lubrication .................................................................................................................................................. 14

11.0 Replacement Parts ..................................................................................................................................... 14

11.1.1 Motor and Trunnion – Exploded View ................................................................................................. 15

11.1.2 Motor and Trunnion – Parts List .......................................................................................................... 16

................................................................................................................................. 11

................................................................................................................................. 12

3.0 Warnings

- 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.

- Al w ays k eep machine guards in place.

- Always put start switch in “OFF” position before plugging in machine.

When using machine:

-Never operate with machine guards missing.

-Always wear safety glasses with side shields (See ANSI Z87.1)

-Never wear loose clothing or jew elry.

-Never overreach — you may slip and fall into the machine.

3.1 Machinery General Safety Warnings

1. Always wear protective eye wear when operating

machinery. 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. No loose clothing or jewelry

which can get caught in moving parts. Contain long hair. Rubber soled footwear is recommended for best footing.

3. Do not overreach. 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. Avoid dangerous working environments. Do not use

stationary machine tools in wet or damp locations, or in an explosive environment. Keep work areas clean and well lit. Special electrics should be used when working on flammable materials.

6. Avoid accidental starts by being sure the start

switch is “OFF” before plugging in the machine.

7. Machinery must be anchored to the floor.

8. Never leave the machine running while unattended.

Machine shall be shut off whenever it is not in operation.

9. Disconnect electrical power before servicing.

Whenever changing accessories or general maintenance is done on the machine, electrical

-Never leave machine running while you are away from it.

-Always shut off the machine when not in use.

When ser vicing machin e:

-Always disconnect machine from electrical power while servicing.

-Always follow instructions in operator’s and parts manual when changing accessory tools or parts.

-Never modify the machine without consulting JET.

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 mandatory that those who use our products be properly trained in how to use them correctly. They should read and understand the Operating Instructions and Parts Manual as well as all label s affi xed to t he machi ne. Fa ilur e to fol low al l of these warnings can cause ser ious injuries.

power to the machine must be disconnected before work is done.

10. Maintain all machine tools with care. 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 machi ne unsafe.

11. Secure work. Use clamps or a vise to hold work,

when practical. It is safer than using your hands and it frees both hands to operate the machine.

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 mach in e on.

15. Use the right tool. Don’t force a tool or attachment

to do a job for which it was not designed.

16. Use only recommended accessories and follow

manufacturer’s instructions pertaining to them.

17. Keep hands in sight and clear of all moving parts

and cutting surfaces.

18. All visitors should be kept 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.

3.2 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.

3.3 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

3.4 Safety requirements for abrasive grinding machines

Abrasive grinding can be hazardous to operators and bystanders. Grinding sparks, chips and dust particles thrown off by the grinding disc can cause serious injury by contact or inhalation. To avoid such injuries you must comply with the following safety requirements:

1. CAUTION: The gap between the abrasive surface and table edge must not exceed 3/16". If it does, loosen the four motor mount bolts and move the motor forward to minimize gap.

2. Always wear protective eyewear when operating machinery. Eye wear shall be impact resistant, prot ecti ve saf ety g la sses w it h side shie lds w hic h comply with ANSIZ87.1. Use of e ye wear which does not comply with ANSIZ87.1 specifications could result in severe injury from breakage of eye protection. See Figure A, below.

3. Wear leather safety gloves, arm guards, leather aprons and safety shoes.

4. A dust collection system is recommended. Operator shall also wear a dust mask at all times. See Figure B, below.

5. Additional precautions may be necessary for grinding materials which are flammable or have other hazardous properties. You should always consult the manufacturer of such materials for instructions on grinding and handling.

6. Do not force or jamb the workpiece into the gri nding disc.

7. Before grinding, always allow the motor to come up to operating speed, then check the grinding

sizes for branch circuits or electrical extension cords according to the following table is recommended:

Conductor Length

0 – 50 Ft. No. 14 No. 14 50 – 1 00 Ft. No. 14 No. 12 Over 100 Ft. No. 12 No. 8

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 grinding operations.

8. 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 Fahrenheit. Failure to do so could cause premature disc failure.

9. Examine the face of the grinding disc carefully. Excessive grinding which wears down to the backing material can result in 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.

10. 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.

11. Always present the workpiece to the wheel while resting the workpiece firmly on the table. Failure to do so could result i n dam age to t he workp iece or throwing of the workpiece off the wheel.

12. Safety shoes which comply with ANSI Z41.1 shall be worn. See Figure C.

13. Personal hearing protection such as ear plugs or earmuffs shall be used to protect against the effect of noise exposure. See Figure D.

240 Volt Lines 120 Volt Lines

AWG Num ber

4.0 General Specifications

The JET Model J-4421 20-inc h diameter disc grinder i s a high prod uction, rapid stock removal tool. The st ock removal rate is controlled by t he amount of pressure t he operator applies to t he work piece and t he grit of the abrasive sheet mounted on the drive disc. By using different grit values and materials, a wide range of materials can be ground and an equally wide range of surface finishes achieved.

Because the Model J-4421 is of heavy-duty design throughout, large piece part s can be ground. The use of either the miter system or the tilt table allows high production grinding of angles. When used in combination, the miter/tilt design allows the grinding of compound angles.

The table tilt mechanism is a rigid, precision worm-and-sector gear controlled with a crank. Table angle is shown on a protractor mechanism.

Table height with respect to the drive disc can be adjusted using a rack and pinion gear system controlled by a crank. The table assembly is counterbalanced to make raising and lowering the table easier and to increase the service life of the lifting components.

Model number ....................................................................... J-4421-2 ..................................................... J-4421-4

Stock numbers ........................................................................ 577010 ....................................................... 577011

.................................................................................. (prewired 220V) ......................................... (prewired 440V)

Motor ....................................................................................................... T EFC, 3HP, 3PH, 220/440V, 1725 RPM

Table size .................................................................................................... 27-1/2 x 10-1/2 in. (68.75 x 26.25 cm)

Disc speed ............................................................................................................................................. 1725 RPM

Disc diameter ................................................................................................................................. 20 in. (508 mm)

Table slot ....................................................................................................................... 3/8 x 3/4 in. (9.3 x 19 mm)

Table tilt ............................................................................................... 45 degrees downward; 15 degrees upwar d

Overall dimensions ............................................................................. 30 x 27-1/2 x 53 in. (75 x 68.75 x 132.5 cm)

Net weight ....................................................................................................................................... 397 lb (180 kg)

Shipping weight ............................................................................................................................... 452 lb (205 kg)

The specifications in this manual were current at time of publication, but because of our policy of continuous improvement, JET reserves the right to change specifications at any time and without prior notice, without incurring obligations.

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