Abstract: A method for determining a smooth machining course for a cutting tool during machining of a workpiece. Each possible cutting tool position, with respect to the workpiece, is defined by a separate reference vector. A progression of points are defined as a tool path. A first specified portion of the reference vector will follow the tool path during machining of the workpiece. A series of reference planes are generated, each plane defines a planar set of all possible reference vector positions for each point. An acceptable range from eahc set is established which defines acceptable reference vector positions within each plane for each point. A tool course is generated, which will be followed by a second portion, distant from the first portion, of the reference vector utilizing an algorithm to minimize irregularities of the course, and to contain the course entirely within the acceptable range.