A Computer Aided Inspection Planning (CAIP) system is a process planner able to automatically plan all the operations related to dimensional inspection of mechanical parts by a co-ordinate measuring machine. In this paper we discuss a interesting CAIP aspect: the probe path generation. Once the system has distributed the measuring points on the part, according to an appropriate sampling strategy, the probe path is obtained by connecting all these measuring points with a collision free trajectory. Due to its complexity, the problem is solved by finding a promising visiting sequence and, then, calculating a sub-optimal collision free trajectory for the sequence. Particularly, we present our novel approach in collision free trajectory generation for a generic multiple tip probe and a generic part.