Visual aids can help the user maintain a straight drilling angle.

Level Method: Attach a small bubble level (torpedo level or line level) securely to the top or side of the drill body using tape or rubber bands. Keep the bubble centered in the level as you drill to maintain vertical alignment.
Mirror Method: Place a small mirror flat on the work surface next to the drilling point. Look at the reflection of the drill bit in the mirror as you drill. Adjust the drill angle until the bit and its reflection form a continuous straight line – this indicates the drill is perpendicular to the surface.

N/A - Utilizes simple visual references (level bubble or reflection) to guide manual drilling.

Use a Level or Mirror for Visual Alignment