Use a Portable Drill Guide Attachment

Clamp a commercially made portable drill guide onto your hand drill or set it on the workpiece to constrain the bit to a perpendicular path.

How It Works

Portable drill guides are lightweight accessories that provide a physical constraint preventing the drill bit from wandering off-angle. They come in two main designs: (1) a base plate that sits on the workpiece with a vertical bushing or channel that the bit passes through, and (2) a guide that mounts directly onto the drill body and extends to the work surface. Both types force the bit to enter the material at 90 degrees by eliminating the possibility of lateral tilt.

Instructions

1. Select a drill guide compatible with your drill and drill bit size
2. For base-mounted guides: place the guide flat on the workpiece with the bushing centered over the drilling mark. Some models have V-grooves for centering on round stock
3. For drill-mounted guides: attach the guide to your drill per the manufacturer's instructions
4. Insert the drill bit through the guide bushing or channel
5. Start drilling at a moderate speed. The guide constrains the bit to a vertical path
6. Once the bit is established in the material (1/4 to 1/2 inch deep), the hole itself maintains alignment

Tips

• Portable drill guides range from $10-40 and are a worthwhile investment for anyone who regularly needs straight holes without a drill press
• The Milescraft 1318 DrillMate ($15-20) is a popular, affordable option with interchangeable guide sizes
• The Big Gator Tools V-DrillGuide ($15-25) features V-grooves that also work on round stock like pipes and dowels
• Some guides include multiple bushing sizes for different drill bit diameters
• A guide is especially valuable for consistent results when drilling many identical holes in sequence

Common Mistakes

• Not holding the guide firmly against the workpiece, which allows it to rock and defeats its purpose
• Using a drill bit diameter that is significantly smaller than the guide bushing, which allows lateral play
• Expecting a $10 guide to match the precision of a $200 drill press — they improve accuracy significantly but are not perfect
• Not center-punching the hole location first, which can cause the bit to wander before engaging the guide