Simulation of 2D cutter paths for CNC machines controlled by stepper motors

CNC machines are used in many applications where the planned path is required to be followed precisely. In addition the motion should be smooth and normally at constant surface speed. Stepper motors are often used to control such machines in an open loop system without feedback. Previous work in our group has involved the development of new interpolation algorithms based on the geometry of the path to generate pulses to control the motion of the stepper motors as stated in Chow (2003) and Chow et al. (2002). The pulse timings can be stored prior to machining to allow further evaluation or investigation. A new simulation system has been developed to provide a visual representation of the expected motion of the machine in real time or with an appropriate delay factor. The simulation also provides speed plots for the two axes, which allow evaluation of interpolation algorithms for smoothness of the motion. Thus, the simulator allows many problems to be detected prior to cutting and therefore can prevent wastage