Motion control has been a fruitful ground for applying Variable Structure Systems (VSS) theory. This paper provides an assessment of the state of the art of the relevant theoretical results for sliding mode control. The design of a sliding-mode controller consists of three main steps. First is the design of the sliding surface, the second step is the design the control law which holds the system trajectory on the sliding surface, and the third and key step is the chattering-free implementation. The main contribution of that paper is a new method for surface sector design based on tensor product model transformation to reduce the chattering. Experimental results of a DSP-controlled single-degree-of-freedom motion-control system are presented.