Makita GB801 8" Bench Grinder Instruction Manual

1. Introduction and Overview

The Makita GB801 8" Bench Grinder is a precision-built electric induction motor tool designed for various grinding applications. It features built-in job lights for enhanced visibility, an easy-to-access on/off switch for convenience, and is equipped with both coarse and fine grinding wheels to suit diverse needs. Adjustable work rests and safety shields are included to ensure precision and user safety during operation. A built-in coolant tray is provided for cooling workpieces.

Figure 1: Front view of the Makita GB801 8" Bench Grinder, showing the two grinding wheels, safety shields, and central motor housing with the power switch.

2. Safety Instructions

Always observe basic safety precautions to reduce the risk of fire, electric shock, and personal injury. Read all instructions before operating this product.

2.1 General Safety Rules

• Read the Manual: Familiarize yourself with the operation and safety procedures before use.
• Eye Protection: Always wear safety glasses or goggles with side shields that comply with applicable standards.
• Work Area: Keep the work area clean and well-lit. Cluttered or dark areas invite accidents.
• Electrical Safety: Do not expose power tools to rain or wet conditions. Ensure the power cord is not damaged.
• Secure Workpiece: Always secure the workpiece firmly to prevent it from moving during grinding.
• Ventilation: Ensure adequate ventilation in the work area to disperse dust and fumes.
• Disconnect Power: Always disconnect the grinder from the power source before making adjustments, changing accessories, or performing maintenance.

2.2 Specific Grinder Safety

• Wheel Inspection: Inspect grinding wheels for cracks or damage before each use. Replace damaged wheels immediately.
• Wheel Guards: Ensure all wheel guards are properly installed and adjusted before operation.
• Work Rests: Adjust work rests to within 1/16 inch (1.5 mm) of the grinding wheel to prevent the workpiece from jamming.
• Clothing: Avoid loose clothing, ties, or jewelry that could get caught in moving parts.
• Coolant Tray: Use the built-in coolant tray to cool hot workpieces, preventing overheating and potential burns.

3. Product Components

The Makita GB801 Bench Grinder consists of several key components designed for efficient and safe operation.

Figure 2: Makita GB801 Bench Grinder with approximate dimensions (length, width, height) indicated.

• Grinding Wheels: Includes one coarse and one fine 8-inch abrasive disc (B-51960, B-51976).
• Wheel Covers: Protective covers for the grinding wheels, featuring built-in job lights.
• Work Rests: Adjustable supports for steadying the workpiece during grinding.
• Safety Shields: Transparent shields that deflect sparks and debris, with an integrated magnifying glass on one side for detailed work.
• On/Off Switch: Large, easily accessible switch for power control.
• Coolant Tray: Integrated tray for cooling hot workpieces.
• Motor Housing: Central body containing the electric induction motor.
• Base: Stable base with rubber feet to minimize vibration.

Included Accessories:

• 8" Bench Grinder (GB801 unit)
• 8" Abrasive Disc (Coarse, B-51960)
• 8" Abrasive Disc (Fine, B-51976)
• Wrench 10-13 (AL00000086)
• Wrench 8-19 (AL00000087)

4. Setup

4.1 Unpacking

1. Carefully remove the bench grinder and all accessories from the packaging.
2. Inspect the unit for any damage that may have occurred during shipping. Do not operate if damaged.
3. Retain packaging materials for future transport or storage.

4.2 Mounting the Grinder

For stable and safe operation, the bench grinder should be securely mounted to a workbench or stand.

1. Position the grinder on a sturdy, level surface.
2. Mark the locations for mounting bolts through the holes in the grinder's base.
3. Drill appropriate holes in the workbench.
4. Secure the grinder using bolts, washers, and nuts (not included) to prevent movement during operation.

4.3 Attaching Components

Attach the safety shields and work rests before initial use.

1. Attach the safety shields to their respective mounting points on the wheel covers. Ensure they can be adjusted freely.
2. Mount the work rests to the grinder. Adjust their position so that the gap between the work rest and the grinding wheel is no more than 1/16 inch (1.5 mm). This minimizes the risk of the workpiece being pulled into the gap.
3. Tighten all fasteners securely.

5. Operating Instructions

5.1 Before Operation

• Ensure the grinder is securely mounted and all guards and work rests are properly adjusted.
• Verify that the grinding wheels are free from cracks or damage.
• Wear appropriate personal protective equipment, including safety glasses, hearing protection, and gloves.
• Clear the work area of any obstructions.

5.2 Grinding Procedure

1. Plug the grinder into a suitable power outlet (100 Volts).
2. Turn on the grinder using the main on/off switch. The built-in job lights will illuminate.
3. Allow the grinding wheels to reach full speed before beginning work.
4. Gently bring the workpiece into contact with the grinding wheel, resting it on the work rest. Apply light, even pressure.
5. Move the workpiece steadily across the face of the wheel to ensure even wear and prevent grooving.
6. For fine grinding or sharpening, use the fine grit wheel. For material removal or rough shaping, use the coarse grit wheel.
7. Do not apply excessive pressure, as this can overheat the workpiece, damage the wheel, or stall the motor.
8. Periodically cool the workpiece in the coolant tray to prevent overheating and maintain material properties.
9. When finished, turn off the grinder and wait for the wheels to come to a complete stop before leaving the machine.

Figure 3: The Makita GB801 Bench Grinder in operation, showing sparks generated during metal grinding. The user is wearing protective gloves.

5.3 Using the Work Lights and Magnifying Glass

The GB801 is equipped with integral work lights that automatically turn on when the grinder is powered on, illuminating the work area for maximum visibility. One of the safety shields features an integrated magnifying glass, providing enhanced visibility for precision work with small objects.

5.4 Using the Coolant Tray

The built-in coolant tray allows the operator to periodically cool the workpiece. This is crucial for preventing the workpiece from overheating, which can alter its material properties or cause burns. Fill the tray with water as needed and dip the hot workpiece into it briefly.

6. Maintenance

Regular maintenance ensures the longevity and safe operation of your Makita GB801 Bench Grinder.

6.1 General Maintenance

• Cleaning: Regularly clean the grinder, especially around the motor vents, to prevent dust buildup. Use a dry cloth or compressed air.
• Inspection: Periodically inspect the power cord for damage. Check all fasteners for tightness.
• Work Rests and Shields: Keep work rests and safety shields clean and free of debris to maintain visibility and proper function.

6.2 Grinding Wheel Replacement

Grinding wheels will wear down over time and need replacement. Always use genuine Makita replacement wheels.

1. Disconnect Power: Unplug the grinder from the power source.
2. Remove Wheel Cover: Carefully remove the wheel cover on the side of the wheel to be replaced.
3. Remove Nut: Use the appropriate wrench (10-13 or 8-19) to loosen and remove the retaining nut and flange. Note the direction of the nut's thread (one side may be left-hand thread).
4. Remove Old Wheel: Slide the old grinding wheel off the spindle.
5. Install New Wheel: Place the new grinding wheel onto the spindle, ensuring it is seated correctly.
6. Reassemble: Replace the flange and retaining nut, tightening securely but without overtightening.
7. Replace Cover: Reattach the wheel cover.
8. Test: Briefly run the grinder to ensure the new wheel runs true and without excessive vibration.

6.3 Lubrication

The motor bearings are typically sealed and permanently lubricated, requiring no additional lubrication. Refer to the official Makita service manual for any specific lubrication requirements if performing advanced maintenance.

7. Troubleshooting

This section provides solutions to common issues you might encounter with your bench grinder.

8. Specifications

9. Support

For further assistance, technical support, or information regarding parts and service, please contact Makita customer service or visit the official Makita website. Keep your product model number (GB801) and serial number (if applicable) ready when contacting support.

For information on Makita's service network or repair options, please refer to the official Makita resources.