For some time now coordinate measuring machines have been an integral part of the shop floor. The goal has been to make coordinate measuring machines (CMMs) into tools that can easily be used by machinists to improve their manufacturing capabilities. The value of a CMM as a quality control tool is undisputed. Now efforts are being made to further reduce the time and cost of measurement by reducing the physical distance between machining and measuring processes. The ability to reduce that distance to zero and measure a part directly on the chip-making machine has been a goal for many years.

Dimensional inspection of parts is primarily conducted by coordinate measuring machines operating on motion instructions from task planning software. The research in direct machining and control (DMAC) at BYU has identified a potential application of CMM technologies on existing machine tools. To prove that a machine tool can be controlled as a CMM with the DMAC controller, this research will integrate the software package PC-DMIS provided by Wilcox Associates, Inc. with a DMAC controller provided by Direct Controls, Inc. to conduct in-process dimensional inspection of parts as they are being machined. This process is referred to as DirectCMM because it will link the DMAC controller directly to PC-DMIS without need for post-processing. This thesis will lay the groundwork for future efforts at developing systems that utilize in-process part inspection to dynamically correct computer aided manufacturing (CAM) process plans.

To aid future efforts at dynamic CAM process updating, a software interface specification will be created for passing measurement data between CMM and CAD/CAM software packages. A CMM control specification will also be created to provide a standard method for controlling coordinate measuring machines with the DMAC controller. Possible methods for dynamic CAD/CAM updating will be explored.



College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering



Date Submitted


Document Type





PC-DMIS, CMM, CNC, DMAC, coordinate measuring machine, machine tool, software controller, machine tool controller, measurement, in-process inspection, DCI, direct control