Extra-Power Tool

A More Powerful Motor

For guys on a job site drilling hundreds of holes a day, power matters—it lets them work faster and blow through knots, nails and other obstructions. That’s why corded tools, with their bigger, stronger motors, still reign for contractors, and why DeWalt challenged its engineers to deliver even more oomph. Their answer: a motor that squeezes in extra copper to deliver 40 percent more power.

Electric motors send current though copper coils embedded in a steel ring, generating a magnetic field that spins an electromagnetic rotor inside. The ring is typically a single piece of metal. Copper coils are inserted through a gap into slots on each side of the ring, and then slid into place. DeWalt instead uses a four-piece steel ring and assembles it around larger coils, eliminating the need for a gap and making room for more power-producing copper.

The motor is now in two new half-inch drills and a handheld grinder, but it could easily migrate to any tool that needs some extra kick.

Stop Gap: In a crosscut of the new motor [foreground, right], copper coils fill the crescent-shaped slots on each side to provide maximum power. The old design [far left] required leaving a gap where the coils were inserted.