ESDU ME3 treats the relationships used in the performance analysis of internal and external Geneva mechanisms driven by a crank rotating at constant or varying speed and transmitting power using a roller bearing or pin. The equations derived are the basis of the program of ESDU 96011 (ESDUpac 9611) and guidance on its use is given in ESDU 96002. The equations cover the key functional dimensions, velocities, accelerations, bearing/contact forces, and driving torques in the principal components. The lubricant entrainment velocity equations are also included. Practical worked examples on the use of the program are in ESDU 96035.