Application and Integration of CAD and CAM Processes in Mechanical Engineering

Glossary:

CAD    - Computer Aided Design

CAM   - Computer Aided Manufacturing

CNC   - Computer Numerically Controlled

SOLIDWORKS  - SolidWorks is a solid modelling computer-aided design and computer-aided engineering computer program

AutoCAD  - AutoCAD is a commercial computer-aided design and drafting software application.

Speeds and Feeds  - Refers to two separate velocities in machine tool practice, cutting speed and feed rate.

Toolpath  - The route through space that the tip of a tool follows when producing the desired geometry of a part.

Abstract:

This report outlines Computer Aided Design (CAD) and Computer Aided Manufacturing (CAM) processes, and how they are applied and integrated in the mechanical engineering industry.

Introduction:

Development of engineering products have historically been divided into two processes, design & manufacture. CAD describes any software used to design and define a mechanical part with geometry, surfaces or solid models. CAM uses software and Computer Numerically Controlled (CNC) machines to automate a manufacturing process. Contemporary CAD/CAM systems can be tightly interconnected allowing in-depth communication between the CAD data and the CNC programming.

What is CAD?

Computer Aided Design is the use of a computer with software, such as SOLIDWORKS or AutoCAD, to aid in the design process; in particular, the design of parts or products.

What is CAM?

Computer Aided Manufacturing is the use of software and CNC machinery to automate manufacturing processes. The main components of a function CAM system include; software that generates tool paths and can convert them into a language the machines can understand, and the machinery that can comprehend the data, converting raw materials into products.

The CAD to CAM Process:

“CAD focuses on the design of a product or part. How it looks, how it functions. CAM focuses on how to make it” (Autodesk, 2018).

The start of the engineering process begins with design modeling; the mechanical design engineer uses CAD software to realize their part, also known as a model, represented as a drawing of CAD data file.

CAD software is used to further refine the part, focusing on the real world machinability/manufacture of the specific part; this involves evaluating and repairing the model and importantly adding manufacturing tolerances. At this stage the engineer will also design part specific molds, fixtures or other required tooling that will aid during manufacture.

Once the model is imported into the CAM software, the engineer or a CNC programmer uses begins prepping the model for machining.

Prepping the model for machining involves:

-          Rechecking the model for any imperfections of geometry errors that could result in improper machining.

-          Creating a set of coordinates for the machine to track during the machining process, know as a toolpath.

-          Setting up machine specific parameters, such as an origin point, speeds and feeds, material thickness.

Running a Toolpath in Solidworks (Solidworks, 2017)

Once the engineer is content that the piece is ready for machining, the information is then sent to the selected machine to physically produce the part. The information is sent to the machine in a language know as G-code, once this is received by the machine, the machine can transform the raw material into a finished part with a single push of a button.

The Benefits of CAD/CAM Integration

Once a part has been designed in CAD, it has to be loaded into CAM. Depending on the software this can either be a simple process as “both CAD and CAM exist in the same world” with “no import/export required” (Autodesk, 2018). The alternative is more convoluted requiring the use of separate, non-integrated CAD and CAM software which creates a “communications barrier between design and production, resulting in cost, time, and quality issues” (Dassault Sytemes, 2013). When using a non-integrated CAD/CAM system the workflow design and manufacture is a linear progression; after the CAD model is finished it is handed over to the manufacturing engineer who has to convert the file and translate the design data that can be read by the CAM program used to program the toolpath. If a fault in the design geometry is uncovered at this stage, the fault will be relayed back to the design engineer will have to resolve the problem, requiring a reset of the process. These changes often occur “late in the process, adding potential costs and delays” (INDUSTR, 2018).

The non-integrated approach to design-through-manufacturing adds unnecessary time and costs related to communication barriers and iterations late in the process (Dassault Sytemes, 2013).

With an integrated CAD/CAM platform you are “working with a single model and data format—with no need to import, translate, or convert data—eliminates chances for error, maintains high levels of accuracy, and minimizes delays related to design errors” (Dassault Sytemes, 2013).

CAD/CAM integration enables a concurrent, collaborative approach to design through manufacturing, which improves communication and quality, and saves time and money. (Dassault Sytemes, 2013).

The lone benefit of standalone CAD and CAM software is they can excel in their specific field cheaper and without compromise; “in general they are faster, easier, and far less expensive than their workstation-based integrated brethren” (3D Systems, 2019).

Conclusion:

The introduction of CAD and CAM integrated processes has revolutionised the engineering and manufacturing industry, and will continue to transform and automate the future of engineering. Whereas early CAD/CAM applications were reserved for exclusive aerospace applications, today this astonishing technology is available to engineering plants of all sizes. Yet, the benefits of CAD/CAM systems are not without their trade-offs; the most notable compromise being the automating away of skilled labour, as well as the high upfront costs of software and machines.

Reference:

• 3D Systems. (2019, April 1). CAD/CAM Integration What’s the Right Choice for You? Retrieved October 15, 2019, from https://www.3dsystems.com/cadcam-integration-whats-right-choice-you.
• Autodesk. (2018, April 27). What is Computer Aided Manufacturing (CAM)? Retrieved October 17, 2019, from https://www.autodesk.com/products/fusion-360/blog/computer-aided-manufacturing-beginners/.
• (2013). Retrieved from https://www.solidworks.com/sw/docs/SW_WP__CAD_CAM.pdf
• INDUSTR. (2018, February 6). Using CAD/CAM to integrate design & manufacturing process. Retrieved October 14, 2019, from https://www.industr.com/en/using-cad-cam-to-integrate-design-manufacturing-process-2321616.
• Solidworks. (2017). Running a Toolpath in Solidworks. Retrieved from https://blogs.solidworks.com/solidworksblog/wp-content/uploads/sites/2/2017/10/launch20image20-20hsm-615×333.png