Draper 44351 Drill Grinding Attachment User Manual

Introduction

The Draper 44351 Drill Grinding Attachment is designed to provide fast and accurate sharpening of twist drills. This attachment is intended for use with a standard bench grinder. It supports a range of drill diameters and offers pre-set angles for various tip requirements.

Key features include:

• Designed for use with a standard bench grinder.
• Accurate sharpening of HSS twist drills from 3mm-19mm (1/8-3/4 inch) diameters.
• Diecast body with pre-set notches for common tip angles: 41° (countersink), 49°, 59°, 68°, and 88°.
• Weight: 0.63 kg (1.39 pounds).

Package Contents

The package for the Draper 44351 Drill Grinding Attachment includes:

• 1 x Draper Drill Grinding Attachment

Setup

1. Prepare the Bench Grinder: Ensure your bench grinder is securely mounted and in good working condition. Select an appropriate grinding wheel for sharpening high-speed steel (HSS) drill bits.
2. Mount the Attachment: The drill grinding attachment is designed to be used in conjunction with a standard bench grinder. It should be positioned adjacent to the grinding wheel. Some bench grinders may require the removal of side protection guards to allow the jig to get close enough to the wheel for proper operation. Always prioritize safety and re-install guards when not using the attachment.
3. Adjust Grinder Rest: Adjust the grinder's tool rest to provide stable support for the attachment. The attachment should be positioned so that the drill bit can make contact with the grinding wheel at the desired angle.

Note: For optimal results, ensure the attachment is firmly secured and stable during operation to prevent movement and ensure consistent sharpening angles.

Operating Instructions

This attachment facilitates accurate sharpening of twist drills. Follow these steps for effective use:

1. Insert Drill Bit: Loosen the clamp on the attachment and insert the drill bit. The attachment accommodates drill bits from 3mm to 19mm (1/8 to 3/4 inches) in diameter.
2. Set Drill Projection: Crucially, ensure the drill bit's projection from the end marker of the attachment is set accurately. This determines the amount of material removed and the final cutting edge. Incorrect projection can lead to poor sharpening results.
3. Select Grinding Angle: The diecast body features pre-set notches for various tip angles. Rotate the attachment to align the desired angle with the grinding wheel. Available angles are:
   • 41° (for countersinking)
   • 49°
   • 59° (common for general purpose drilling)
   • 68°
   • 88°
4. Grind the First Flute: With the grinder running, carefully bring the drill bit, held by the attachment, into contact with the grinding wheel. Apply gentle, consistent pressure. Grind one flute until a sharp edge is achieved. Avoid overheating the drill bit by applying light pressure and cooling if necessary.
5. Grind the Second Flute: Rotate the drill bit within the attachment to present the second flute to the grinding wheel. Ensure the same angle and projection are maintained. Grind until the second flute matches the first, creating a symmetrical and sharp cutting edge.
6. Check Sharpness: After grinding, inspect the drill bit for sharpness and symmetry. Both cutting edges should be uniform and sharp. Practice on old drill bits is recommended to achieve proficiency.

Tip: Start with larger drill bits (e.g., 5mm and above) when first using the attachment, as they are generally easier to sharpen. Smaller drill bits require more precision and a gentler approach.

Maintenance

• Cleaning: After each use, wipe down the attachment to remove any grinding dust or debris. A dry cloth is usually sufficient.
• Storage: Store the drill grinding attachment in a clean, dry place to prevent corrosion and damage.
• Inspection: Periodically inspect the attachment for any signs of wear or damage. Ensure all moving parts operate smoothly and that the clamping mechanism is secure.

Troubleshooting

• Poor Sharpening Results:
  • Ensure the drill bit projection from the attachment is accurate and consistent for both flutes.
  • Verify the grinding wheel is suitable for HSS and is not worn or glazed.
  • Confirm the selected angle on the attachment matches the desired tip angle for the drill bit.
  • Apply light, consistent pressure to avoid overheating or removing too much material.
• Drill Bit Overheating:
  • Reduce grinding pressure.
  • Take breaks to allow the drill bit to cool.
  • Consider using a finer grinding wheel if excessive heat is a persistent issue.
• Attachment Not Stable:
  • Ensure the bench grinder's tool rest is properly adjusted and secure.
  • Verify the attachment is correctly positioned and not obstructed by grinder guards.

Specifications