Northfield Automation Systems (NAS), which designs, engineers and fabricates automation machinery for OEMs and high-volume manufacturers, is celebrating its 20th anniversary on Sept. 25.   “We haven’t skipped a beat,” said Mark Wegner, president of NAS. “We have continued to find opportunities to keep our business thriving, and a big part of that is staying on the cutting edge of technology and having a great team here at NAS all along.”    NAS, which is based in Northfield, MN, has deve...