This paper deals with the analysis and synthesis of slider-crank mechanisms, which are aimed to give suitable coupler curves for automatic machinery, as path generators. A practical method for the dimensional synthesis of slider-crank mechanisms is proposed by referring to a classical approach, which is based on the use of the centrodes, inflection circle, cubic of stationary curvature, cubic curve of centers and Ball’s point. Usually, in the industrial practice, the generation of a specific continuous path is not required because, very often, only the shape and the overall size of a coupler curve is sufficient to satisfy the design specifications. Thus, this paper gives a contribution to the dimensional synthesis of slider-crank mechanisms by formulating a practical and intuitive procedure, in order to obtain two different shapes of path, a symmetric egg shape path with a straight segment part and/or stationary curvature and a raindrop shape path, which both respect the required overall sizes.