Motion compensation for five-axis rapid prototyping system

In view of the "staircase or stepped effect" in the present commercial rapid prototyping (RP) systems, a new approach is proposed, and is currently under development to produce true stepless parts. The new RP system is a combination of five-axis motion control technology and precision milling. The system consists of three linear and two rotary axes, which enable the milling tool to be orientated for tangent cutting. Because of the complexity of the five-axis configuration, ensuring high accuracy and precision is both important and difficult. This paper presents an open-loop motion compensation algorithm, which enables the machine tool to move more accurately to a given position and orientation than its physical setup allows. Experimental procedures to measure the geometrical errors in the system setup are also presented in this paper.