Post- Processing

Introduction
From an ICAM Technologies Corporation (ICAM) perspective, this article will attempt to explain the complete manufacturing process from market demand to finished product. This article will also illustrate the integral role of post-processing within a series of manufacturing actions.

Market Demand

The first element of the manufacturing process ultimately originates from a market demand for a finished product, which usually consists of an assembly of uniquely manufactured parts. In this example, ICAM will illustrate the role of post-processing when manufacturing an impeller, a uniquely manufactured part included within an assembly of parts to produce a jet engine, a finished product conceived to satisfy a market demand for efficient and reliable international travel.

Step 1- Part Design

The design of the impeller is usually produced by a design engineer using a specialized software product commonly referred to as a CAD (Computer Aided Design) system.
The design engineer will use the CAD system to design and draw the impeller within a virtual three dimensional space containing the impeller's dimensions and other pertinent product specifications.

Step 2- NC Program

The final impeller design produced by the design engineer is then handed to a manufacturing engineer. Using a CAM (Computer Aided Manufacturing) software product, the manufacturing engineer will add all the necessary machine logic required to manufacture the impeller on a NC machine – a computer automated machine that will be used to manufacture the impeller. Any changes deemed necessary to the impeller design will be executed during this phase. The final CAM output generated from the manufacturing engineer is referred to as the NC program.

Step 3 - NC Post-Processing

Once the NC program containing the impeller design as well as the machining logic has been created by the manufacturing engineer, the NC program is exported into a standard computer-aided NC programming language such as Automatically Programmed Tools (APT). Subsequently, a post-processor is created using ICAM's NC post-processing software, CAM-POST^®, to translate the APT file to Machine Code Data (MCD). The MCD is is compatible with a specific NC machine selected to machine the impeller.

Step 4- MCD Simulation

The MCD is then tested for program errors such as collisions and over-travel using ICAM's graphical machine simulation software product, Virtual Machine^®. This special product can detect programming errors and provide the possibility to optimize the MCD or the original NC post- processor before initiating the machining process on the actual NC machine. This phase is critical as it will avoid expensive repairs to the NC machine resulting from an NC program that contained unforeseen programming errors.

Step 5- Machining the Impeller

The MCD containing all the machine motion logic required to produce the impeller is uploaded to the NC machine controller- the computer interface of the machine tool. The stock, the material that will ultimately form the impeller, is fitted to the machine and the machining process is then executed by the machine operator. The impeller is then removed from the NC machine cleaned and inspected for imperfections.

Step 6- Product Assembly

The final phase of the manufacturing process is the installation of the impeller within an assemble of related parts ultimately forming the finished product – a jet engine. This step is performed by highly specialized technicians and mechanics.

Conclusion

As of today, no CAD / CAM output and MCD standards have been developed or are being developed; therefore, NC post-processing remains a critical element that "bridges the gap" between these two distinctive technologies, currently and for the foreseeable future.

ICAM Technology- Advanced NC Post-processing and Machine Tool Simulation