To add visceral realism to its helicopter flight simulator, engineers at Wittenstein Aerospace & Simulation, Bartlett, Ill. (, designed a seat shaker that provides seat vibrations similar to those experienced by helicopter pilots. The design relies on a compact industrial actuator and mechanical linkage that fit under the seat. Both frequency and amplitude are adjustable from 0 to 40 Hz and from 0 to 6 mm, respectively. The controls are housed in a 19-in. rack controller with a power supply. The seat shaker, dubbed The Vibe, can be powered from a standard wall outlet (115/230 Vac) and set to mimic a variety of aircraft.