A wing-drive mechanism includes at least one sub-mechanism having a motor that drives a drive shaft in a single direction. The sub-mechanism includes a converter means for converting the rotary motion of the drive shaft to a linear or arcuate back-and-forth motion; amplitude control means for controllably varying the extent of the linear or arcuate back-and-forth motion produced by the converter means; and a rotatably mounted output mechanism engaged with the converter means such that when the converter means produces the linear or arcuate back-and-forth motion, a corresponding alternating rotary motion is imparted to the output mechanism. In other embodiments, the invention is also a wing-drive mechanism and a method for configuring pairs of wing-drive mechanisms.