The low hum of 3D printers echoed through the historic warehouse in Brooklyn’s Sunset Park District this morning as MakerBot ‘Productors’ were busy at work building Replicator 2’s and 2X’s. Today, Bre Pettis and NYC city representatives presented the all new MakerBot Factory…a two-story 50,000 sq ft warehouse filled with nothing but…you guessed it…MakerBots up…