Delta GR450 - User Manual

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Summary

Safety Guidelines and Definitions

General Safety Rules

Important Safety Instructions

Emphasizes following all warnings and instructions for safe operation to prevent injury.

Grounding Instructions

Grounded Cord-Connected Machines

Explains grounding requirements for machines with a grounding plug and proper outlet connection.

Grounded Machines for <150 V Circuits

Details using temporary adapters for grounded circuits when a proper outlet is unavailable.

Functional Description

Foreword

Introduces the Delta ShopMaster Model GR450 8" Variable Speed Grinder and its features.

Assembly

Tool Rests Assembly

Instructions for attaching, positioning, and adjusting the tool rests for optimal support.

Spark Guards Assembly

Guidance on mounting and adjusting spark guards to protect the operator from sparks.

Eye Shields Assembly

Steps for attaching eye shields to the grinder for eye protection.

Fastening Grinder to Supporting Surface

Instructions on how to secure the grinder to a supporting surface to prevent tipping.

Operation

Starting and Stopping the Grinder

Procedure for turning the grinder ON using the switch and turning it OFF.

Locking the Switch in the Off Position

Method to lock the switch in the OFF position to prevent unauthorized startup.

Parts, Service, and Warranty Assistance

Two Year Limited Product Warranty

Porter-Cable Delta Service Centers

The device described in the manual is an 8" Variable Speed Grinder, Model GR450, manufactured by Delta ShopMaster.

Function Description

The Delta ShopMaster Model GR450 is an 8-inch variable speed grinder designed for various grinding, sharpening, and buffing applications. It is equipped with two grinding wheels and can also accommodate a buffing wheel for polishing tasks. The variable speed control allows the user to adjust the rotation speed of the wheels, making it suitable for different materials and tasks. The grinder includes safety features such as adjustable tool rests, spark guards, and large eye shields to protect the operator during use. A flexible lamp is also integrated to illuminate the work area.

Important Technical Specifications

Model: GR450
Type: 8" Variable Speed Grinder
Power Source: 120V, 60 Hz alternating current. Requires a separate electrical circuit, not less than #12 wire, protected with a 20 Amp time lag fuse.
Speed Control: Variable speed.
- Minimum RPM (counter-clockwise position): 1725 RPM
- Maximum RPM (clockwise position): 3450 RPM
Grinding Wheels:
- Diameter: 8 inches
- Arbor Hole: 5/8 inches
- Width: 1 inch (Using wheels less than 1" wide can cause vibration and damage).
- Rated RPM: 3600 RPM or higher.
- Supplied with: Two aluminum oxide grinding wheels (36 grit and 60 grit).
Buffing Wheel: Can be installed in place of a grinding wheel.
Lamp: Flexible lamp, requires a 40 watt or smaller, 120 volt, reflector track type light bulb (not supplied). Standard household light bulbs should not be used.
Mounting: Designed to be fastened to a supporting surface to prevent tipping, sliding, or walking during operation.

Usage Features

Variable Speed Control: The grinder features a knob to adjust the rotational speed from 1725 RPM to 3450 RPM, allowing for precise control depending on the material and desired finish.
On/Off Switch: Located on the front of the grinder for easy access.
Switch Locking Mechanism: The switch toggle can be removed to lock the grinder in the "OFF" position, preventing unauthorized use. If removed while running, the machine can be turned off but not restarted without the toggle.
Adjustable Tool Rests: The tool rests are adjustable to be positioned slightly below the centerline of the wheel and as close as possible (1/8" or less) to the grinding wheel, providing maximum support for the workpiece. They must be tightened securely to prevent shifting.
Adjustable Spark Guards: These guards are mounted to the side of each wheel guard and should be adjusted close to the grinding wheel to prevent sparks from striking the operator's hand.
Eye Shields: Two large eye shields are provided and must be properly installed and adjusted to protect the operator's eyes from flying debris.
Flexible Lamp: An independent lamp illuminates the work area, enhancing visibility during operation.
Quick Release Arbor Nut System: Facilitates easier changing of grinding wheels and buffing wheels. The arbor nut wings must be flat against the arbor flange to prevent vibration.
Workpiece Feeding: Workpieces should always be fed against the direction of the wheel's rotation.
Grinding Technique: Grinding should be done on the face of the wheel only, and freehand grinding should be performed on the lower quarter of the wheel.
Buffing Wheel Installation: The manual provides detailed instructions for installing a buffing wheel, including the use of a buffing wheel bushing and ensuring proper arbor nut wing contact.

Maintenance Features

Wheel Dressing: The grinder comes with a wheel dresser (or a suitable silicone carbide stick type dresser can be used) to maintain the grinding wheels. Wheels should be dressed on the face only to keep them clean and with square edges. Dressing also helps maintain balance and prolong bearing life.
Wheel Inspection: Grinding wheels must be inspected for cracks or fragments before each use. Damaged wheels must be replaced immediately.
Tool and Machine Condition: All tools and machines should be kept sharp and clean for optimal and safe performance. Lubrication and accessory changes should follow instructions.
Damaged Parts Check: Before use, operators should check for damaged parts, including alignment of moving parts, binding, breakage, and any other conditions affecting operation. Damaged guards or parts must be repaired or replaced.
Work Area Cleanliness: The work area should be kept clean and free of clutter.
Dust Removal: Precautions against dust inhalation are emphasized. Operating in well-ventilated areas and using wood dust collection systems are recommended, especially when grinding wood or wood products.
Cleaning: The machine should be thoroughly cleaned, especially when switching between different workpiece materials (e.g., wood, steel, aluminum) to prevent fire or explosion hazards from mixed dust.
Protective Coating Removal: Upon unpacking, protective coating on unpainted surfaces should be removed with a soft cloth moistened with kerosene, followed by applying a good quality household floor paste wax.
Extension Cord Maintenance: Extension cords should be kept in good condition, and damaged or worn cords should be repaired or replaced immediately.
Bearing Life: Using balanced wheels and properly dressing them contributes to extending the life of the grinder's bearings.