newsmaker/add/jas/mike1st/mark2nd High-Tech/Aerospace 3D Systems Corp., a Valencia-based developer, marketer and manufacturer of solid-imaging systems, has appointed Richard Balanson to the positions of president and chief operating officer. The company’s founder, Charles W. Hull, will assume the posts of vice chairman and chief technology officer. Prior to joining 3D Systems, Balanson was executive vice president of Maxtor Corp., a supplier of computer disk drives, where he headed engineering, manufacturing, materials, sales and marketing activities.