Abstract
This paper introduces the geometric event constraint for the automatic design synthesis of mechanisms. Using a Lagrange type I formalism event constraints and dummy particles can efficiently find the optimal joint configuration in mechanism design studies. Two examples are presented using nonholonomic and holonomic event constraints. The holonomic system is simulated for a locus of optimal performance joint locations during mechanism articulation, providing both synthesis and analysis in one simulation. Desired system response, dependent on joint configurations, is obtained using standard multibody dynamics software avoiding additional special purpose code or optimisation routines.