Support WBURFixing The Cutting Edge: Innovation Meets Table SawPlay03:46Download AudioChris ArnoldApril 02, 2012 ShareThe table saws in David Butler's (left) workshop are outfitted with prototypes of his "Whirlwind" safety brake system. He and his lifelong friend Robert Calhoun filed their first Whirlwind Tool Co. patent in 2009. (NPR)
