A ROBOTIC roller skate propels itself across the fifth floor of an old sewing factory at 397 Bridge Street in Downtown Brooklyn. The softly lighted room is permeated by an acrid odor emanating from soldering irons and recently extinguished birthday candles.

Over the thump of electronic rock, two dozen men and women chat, type at laptops and pull on tangles of wire. “Firing the laser!” someone shouts. An electronic sign attached to the wall blinks: “Welcome — to — the — 21st — Century.”

The 800-square-foot space belongs to a hacker collective called NYC Resistor, which opened in the summer of 2007, and already has inspired a clone. The collective has turned away those who are interested in fraudulent computer hacking, preferring a membership of tinkers and inventors — mostly self-professed nerds — each of whom pays $75 a month for access to the space and equipment.

“People think hacker means a criminal,” said Devon Jones, a 33-year-old member of the collective who was slumped on a ratty couch drinking a beer. “Well, we want our word back.”