Tool trend: Brushless motors

Brushless and conventional motors

For a kid rummaging around Grandpa’s workshop, circa 1972, an unattended power drill was a magical thing. Pull the trigger, and not only did the bit spin, but through the cooling vents you could see sparks—real, raw electricity—dancing and glittering. Cool.     

Not so cool for anyone using the tool all day. Those sparks are caused by the motor’s carbon brushes, feeding electricity through commutator bars on the spinning armature. The longer and harder the drill works, the more friction between moving parts. The tool gets hot, the brushes wear down, and the cranking power is drained by heat and sparks.

That’s why power-tool makers are introducing tools with cooler, more efficient brushless motors. When engineers swap brushes for an electronic controller (and rework the motor so the windings are on the outside, while the magnets spin on the shaft), cordless tools gain longevity and power, and the battery lasts longer.

Brushless motors aren’t new, but until recently their uses were restricted by their relatively high cost. About a decade ago, they started showing up in tools for the pros. Now they’re “more and more widespread” for serious DIY users, says Matthew Noel, product manager for Makita Canada. Like DeWalt, Milwaukee, and other makers, Makita is putting brushless motors into everything from impact drivers and hammer drills to brush cutters and trimmers. They make the most sense in frequently used tools; you probably won’t pay the roughly 40 per cent premium for a brushless tool that sits in the shed most of the time.

But for hard-core cottage handymen putting in long hours, going brushless is a good investment. A brushless tool stays cooler in your hand during a full day of work and, best of all, offers as much as 50 per cent longer run time on a single battery charge. That’s magic even a grown-up can admire.