**3. Conclusions**

Phase-plane diagram and Poincare map are used to detect the nonlinear dynamics phenomenon in radial cam and flat-faced follower mechanism at different cam speeds and different contact condition of the material properties. As stated, the level of chaos of steel greasy material in nonlinear dynamics behavior is more than the level of chaos of nylon material properties due to the contact between the cam and the follower. The peak of rise stroke is increased for steel dry and greasy while it decreases for nylon and acrylic material properties. The dwell stroke is varied and increased with the increasing of guide's clearance of aluminum greasy material properties. The level of chaos of nonlinear dynamics of steel greasy is more than the level of chaos of aluminum greasy since this level is increased with the increasing of cam speeds.
