Abstract: This paper presents a new method for machining function curves to directly generate the specified feed rate and derive the controlled model from the equation of the function curve . With the proposed method, the speed of the stepping motor of each axis is directly controlled, realizing the given synthetic feed rate and motion trajectory of the machining point. At the same time, it effectively solves the contradiction between the precise stepping of the curve and the capacity of the control system. Simulation results verify the correctness and feasibility of the proposed control method. Keywords: stepper motor; CNC; feed rate ; control; function curve This is of great importance for keeping the stepping motor retting steadily without missing steps. Meaning is the connection between the stepping motor's position and the CNC machine's memory resolved. The predictability and feasibility of the proposed method have been verified with the provided intersecting curves. KEY word : stepping motor; CNC; feedrate; control; functional curves 1 Introduction Stepping motor drive systems have significant advantages such as low cost and simple control, and are widely used in CNC systems. An important issue in machining process control is the control of the synthetic feed rate, which directly affects machining accuracy and is closely related to equipment lifespan and production efficiency. Common interpolation methods used for motion trajectory control include: point-by-point comparison method, digital integration method, and time division method. The synthetic feed rate is related to the feed rate pulse source frequency, interpolation method, programming method, and machining dimensions, making it difficult to adjust the feed rate according to the production process requirements during machining. The motion trajectory of the machining point is a planar curve or a three-dimensional spatial curve. Most machining processes and mechanical equipment are regular shapes, which can be represented by mathematical analytical expressions, and are mostly non-circular function curves. The interpolation methods mentioned above first require mathematical processing to approximate the machined curve with a straight line or circular arc. This precise approximation of the curve contradicts the capacity of the CNC system. Furthermore, the components of the straight line or circular arc segment on each axis are usually not integer multiples of the pulse equivalent, reducing the feed rate and causing trajectory errors. With the continuous improvement of modern microcomputer performance and computing speed, interpolation speed is no longer the main factor affecting CNC machining. To address this, based on the proposed timed interpolation method and the development of a microcomputer-controlled wheel cutting machine, we have conducted in-depth research on the trajectory control and speed control of general function curves, and proposed a new method for directly generating function curves with high precision and feed rate control. [b][align=center]For details, please click: Direct Function Speed ​​Control Method for Stepper-Driven CNC Systems[/align][/b]