The invention thus comprises an extended contact harmonic drive gearing apparatus for transmitting rotary motion from an input drive to an output drive, comprising: a rigid circular spline having gear teeth thereon; a flexible flexs pline having gear teeth thereon arranged radially adjacent the rigid circular spline; an oval wave generator having a major axis and a minor axis arranged radially adjacent the circular spline, and adapted to deform the flexspline whenrotated, to generate a rotative motion between the flexspline and the circular spline; the flexspline having a minor axis thereacross with maximum radial separation between the gear teeth of the flexspline and the circular spline; the flexspline having a major axis thereacross with a maximum engagement between the gear teeth of the flexspline and the circular spline; the gear teeth on the flexspline having a precessing inclination and back again as they pass from the minor axis to the major axis thereon with respect to the oval shaped wave generator