CAM – Computer-aided Manufacturing

What does the term CAM stand for?

CAM (Computer-Aided Manufacturing) stands for the computer-aided creation and planning of manufacturing processes. If you think of the milling process as an example, the CAM process includes the definition of tools, clamping devices and zero points.In addition, machining strategies and work sequences are specified here, which lead to an NC program (NC = numerical control; an NC program is a program for controlling a numerically controlled machine tool). Furthermore, manufacturing processes can be simulated in CAM in order to check the generated NC program for errors or collisions. For this purpose, the program can create a 3D model, for example.

Definition and explanations

Computer-Aided Manufacturing (CAM) refers to the use of software independent of the CNC (Computerized Numerical Control) machine to generate NC code and is part of the manufacturing or preparation technology (in companies). NC code can be used to control cutting machines or 3D printers, among other things. In contrast to the generation of the NC code in the workshop (WOP), in the CAM system the NC program is already created during work preparation. CAM is an integral part of Computer Integrated Manufacturing (CIM).

Instead of conventional drawings, the NC program for the part to be produced must be created directly from the CAD data generated on the computer. The necessary instructions for the CNC machine and the instructions for the operator no longer need to be printed out, but simply transmitted to production in electronic form. In addition to the operation of the machine, the preparatory support is directed, for example, to the management and provision of raw and auxiliary materials as well as individual parts. Production employees receive production plans and instructions directly on the system or on the screen.

In CAM, the raw data for the production of individual parts and the assembly of subassemblies is collected, sorted according to work steps and managed according to dependencies. This includes interfaces that, for example, read dimension and material and parts lists from CAD systems and make them available for processing. In addition to the functions already available in computers, additional information is entered. This can be, for example, a comparison of CAD drawings and parts lists from production planning and control, as well as data required for production such as fixture plans, tool requirements and machining sequence.

Codes or material requirements to be processed directly by the machines are then specially entered into the system and retrieved by the operator. In this area, the interfaces are also required for machine control or the storage system. After processing or completing production steps, it may be necessary to further process the verified results and transfer them to other processes in computer-integrated manufacturing through additional interfaces. In addition to proper order-related data processing, CAM tasks also include archiving and standardization.

CAM - Fields of application & use cases

CAM benefits include a clearly defined manufacturing plan that can be used to achieve expected production results. CAM systems can optimize the use of a wide range of manufacturing equipment, including five-axis, high-speed, multi-function and turning machines, EDM machines and CMM machines. CAM systems help create, validate and optimize CNC programs for the highest possible machining performance and automate the generation of production documentation. State-of-the-art CAM systems with integrated product lifecycle management (PLM) enable production planning and manufacturing personnel to manage data and processes to ensure the right data and standard resources are used. To transfer and manage files on CNC machines, CAM and PLM systems can be integrated into DNC systems (Distributed Numerical Control; embedding CNC machines in LAN or WiFi) on the shop floor.

Use cases of CAM systems

Example 1

A leading power sports and motorsports piston and rod company uses application programming interfaces (APIs) and an integrated CAD and CAM solution to fully automate the design and programming of product details. When an order is received, sales engineers enter specifications into a user interface created with the APIs. After model specifications are entered, the software automatically generates the analysis model and toolpaths for the part, and after a brief preview, production can begin. This integrated, automated approach reduces overall lead times by 85 percent. This is achieved by reducing design time by 95 percent, CNC programming time by 75 percent and scrap and rework by 20 percent.

Example 2

Instead of using traditional impression materials, a dentist creates a digital model of your teeth. A special small camera scans your jaw, the teeth and especially the affected teeth and creates a three-dimensional image on the computer. If you need a milled crown or bridge, for example, the prepared tooth can be shown in detail with the camera, which is not always possible with impression material. The software can also be used to correct inaccuracies. This is necessary for the precise fit of your computer-planned denture. The desired crown or bridge is then designed, machined and precisely adapted to the oral environment using special software.

In the case of the crown or bridge as a dental prosthesis, the CAD process is upstream of CAM (CAD/CAM). CAD has become very widespread because it greatly simplifies the planning processes and you only need a few clicks for various modifications. In dentistry, the process is such that the dental technician responsible for planning uses a 3D scanner and software to complete a 3D model of the patient's plaster cast. Then, computer planning software creates a digital version of the desired prosthesis.

Based on the parameters entered, the entire planning process is supported by the software, which also ensures that the planned prosthesis has the appropriate properties. The created 3D plan is processed by a dental technician using a CNC milling machine. The computer-controlled programmable milling machine enables digital design with unique precision. The patient can rely on the final result, which is achieved with an accuracy of several micrometers (unlike conventional dentures, whose accuracy is only 70-80 micrometers).

What is the difference between CAD and CAM?

CAD focuses on the design of a product or manufacturing part, CAM organizes the workflows. The start of any design process begins in the CAD world. Engineers produce either a 2D or 3D drawing, whether it's the crankshaft of a car or the inner frame of a kitchen faucet. In CAD, each design is considered a model and contains certain physical properties that are used by the CAM system.

Another advantage is the overall user experience. CAD is particularly suitable for parts of medium to high complexity, such as 3D free-form surfaces. The field of application is mainly the production of single and small series products, such as in the production of models, molds and tools. CAD technology has proven itself in the construction and drawing industry. Many product models (drawings) are created using CAD. However, only a few integrate the generated data directly into an NC program. A wide variety of CAD systems are available for a wide range of applications such as mechanical engineering, architecture, electronics and printed circuit board design and more.

Computer-aided design (CAD) uses computers to turn a rudimentary product idea into a detailed construction project. This involves the creation of geometric product models that can be manipulated, analyzed and refined. On the other hand, computer-aided manufacturing (CAM) involves the use of computers to help managers, process engineers and production workers automate production tasks and manage machines and systems.

CAD includes processes such as geometric model definition, interface translation, definition, design and analysis algorithm, detailing, design and final documentation. In contrast, CAM includes processes such as numerical control programs, geometric modeling, interface algorithms, process planning, control, assembly, and packaging.

A CAM system requires control and coordination of a physical process, equipment, materials and labor, while CAD requires a concept and analysis of the product design.

CAD benefits:

• Scaling and scaling changes in drawings and models are easier, more automatic, and more accurate

• Minimizes the need for large numbers of expensive drafters for product development

• Allows cutting data to be generated directly for CNC machine tools

• Design data can be transferred to computerized production control systems

• It is easier to store and retrieve models

• Multiple copies can be stored, printed and transferred electronically, eliminating the need to store large paper drawings

• Accurate 3D models can be examined before expensive materials are produced

• This increases production speed and requires less labor

Benefits of CAM:

• The machines are precise and production can be repeated over and over in large batches

• Production requires minimal supervision and is therefore less labor intensive and labor saving

• The occurrence of errors is negligible and the machines can run continuously

• Virtual machining allows on-screen evaluation of operations and machining results

• Prototypes can be quickly prepared for comprehensive testing before the design is finally ready for mass production

How do CAD and CAM work together?

Once the structure is completed in CAD, it can be imported into the CAM program. Traditionally, this is done by exporting a CAD file and then importing it into CAM software. With certain tools, both CAM and CAD coexist in the same world, so no export/import is required.

Preparation for processing

After the CAD model is imported into the CAM software, the program starts preparing the model for processing. CNC processing is the controlled work process of transforming raw materials into a specific shape through actions such as drilling, cutting, or milling. The CAM software prepares the model for processing by performing several steps, including:

• Verification of the presence of geometric errors in the model that affect the production process.
• Creation of a tool path for the model, a set of coordinates that the machine will follow during processing
• Setting all the necessary machine parameters such as clamping, cutting speed, cutting/grooving height, etc.
• The CAM system configures the best part alignment to maximize machining efficiency

Transport of data to the processing machine

When the model is ready for processing, all the information is sent to the machine that physically manufactures the part. However, a set of instructions cannot simply be passed to the CNC machine. In order to address the equipment in "machine language," the processing information is converted into a language called G-code. It is a set of instructions that control the actions of the machine, including feed rate, speed, coolant. G-code is easy to read if you understand the format.

An important component of the CAM module is the built-in postprocessor (PP), which must be adapted to geometry and control technology depending on the machine used. This allows an NC program created in CAM to be simulated identically to a G-code control and output with the corresponding control-specific syntax.

The advantages of automated manufacturing over WOP systems should have become clear. But CAM software does even more: processes are further optimized through a high level of networking with other applications. The application can communicate directly with a tool management system or a PPS system, in particular to transmit set values directly to a presetting device for measurement. These capabilities lead to improved data and process management and facilitate the creation of production documentation.

Disadvantages with sequential, non-integrated design approaches

To better understand the potential benefits of an integrated CAD / CAM platform, it is helpful to compare the workflow of a traditional, sequential, non-integrated design approach with the parallel collaborative workflow of an integrated CAD / CAM platform. Each approach is reviewed and described in detail for both injection molded and machined parts.

When using incompletely integrated CAD and CAM systems, the workflow between design and development is a linear sequential transfer of design data with the potential costs and delays caused by later changes in the development process. Once a design is released for production, workers must import, convert or transfer the data to a file that they can use to program toolpaths for machining parts or molds. Difficulties due to structural geometry, material cost or manufacturability must be sent back to the designer for resolution, and the process begins again.

Problems of this nature often go unnoticed until tooling is created and production begins, resulting in costly scrap and rework. In addition, solving such a problem usually requires additional linear variations between design and manufacturing. Manufactured solutions are sometimes chosen for convenience rather than quality to avoid further changes and even more labor costs.

For molded parts, additional linear steps are required to create a mold prototype, mold base and mold inserts. Again, subsequent shape improvement options such as slope, fill, and parting line issues require a lot of additional work and multiple transfers between design and manufacturing. Even more disruptive are design changes or design change orders (ECOs) that result from the design of a product for which production must be restarted. A non-integrated approach from design to production has several drawbacks, the most important of which is the increased risk of inaccuracies. Errors can occur when a file needs to be converted, translated, or imported from one data format to another.

FAQ about CAM

What is CAM?

Computer-aided manufacturing (CAM) refers to the use of computers to automate production tasks and manage machines and systems. CAM processes include numerical control programs, geometric modeling, interface algorithms, process planning, control, assembly and packaging of products. CAM is used to organize work processes.

How are CAM and CAD related?

The technology behind the abbreviations CAD and CAM has been around since 1965, meaning Computer Aided Design and Computer Aided Manufacturing. The merging and networking of these areas and their CAx techniques have recently come to the fore. In manufacturing engineering, the development of CAx methods has been targeted at tasks that today can be classified as CAD and CAM. The first study was conducted in the early 1950s at the Massachusetts Institute of Technology (MIT) on numerically controlled machine tools.

Which technical areas are important for CAM?

Three technical areas are fundamental to the creation of a new product: design, calculation and manufacturing. CAx methods, of which CAM is a part, are used in all three areas. The CAx concept has two goals: Firstly, the individual functional areas of the company are to be integrated more closely. Secondly, there is to be a constant flow of data between different areas of the company.

What problems can occur with CAM?

The problems in implementing the CAx concept relate to the following areas: Costing, Design and Production (CAM). They can occur both at the organizational level (who has access to which data?) and at the information technology level (databases, interfaces, HW, SW) and cause complications.

What is the starting point for the CAM process chain?

The starting point for the CAD/CAM link is the internal computer-aided (3D) CAD model. Its capabilities are simulated or stored in a computer. A variety of interfaces are available for geometry exchange between different CAx tools. Computer programming CAD/CAM is directly in the area of creating 3D CAD geometry. Often, by integrating a CNC programming module into a CAD system, the generated CAD data can be used in the same data format without an interface for CNC programming.