Everything you need to know about Computer-Aided Manufacturing (CAM)
Computer-Aided Manufacturing (CAM)
Computer-aided manufacturing (CAM) uses computers to assist in the creation or modification of manufacturing control data, plans, or operations and to operate machine tools. Computers are
integral to the manufacturing process. Computerized tools such as welding machines, machining centres, punch press machines, and laser-cutting machines are commonplace. Many firms are engaged in computer-aided design/computer-aided manufacturing (CAD/CAM). In a CAD/CAM system, a part is designed on the computer and transmitted directly to computer-driven machine tools that manufacture the part. Within the CAD/CAM process, there are other computerized steps along the way, including the following:
STEP 1 The CAD program is used to create the product geometry. The geometry can be in the form of 2-D Multiview drawings or 3-D models.
STEP 2 The drawing geometry is used in the CAM program to generate instructions for the CNC machine tools. This step is commonly referred to as CAD/CAM integration.
STEP 3 The CAM program uses a series of commands to instruct CNC machine tools by setting up tool paths. The tool path includes the selection of specific tools to accomplish the desired operation.
STEP 4 The CAM programmer establishes the desired tool and tool path. Running the post-processor generates the final CNC program. A postprocessor is an integral piece of software that converts a generic, CAM system tool path into usable CNC machine code (G-code). The CNC program is a sequential list of machining operations in the form of a code that is used to machine the part as needed.
STEP 5 The CAM software simulator verifies the CNC program (see Figure).
STEP 6 The CNC code is created. Figure 3.26 illustrates the CADD 3-D model, the tool and tool holder, the tool path, and the G-code for machining a part.
STEP 7 The program is run on the CNC machine tool to manufacture the desired number of parts.
Computer Numerical Control (CNC)
Computer numerical control, also known as numerical control (NC), is the control of a process or machine by encoded commands that are commonly prepared by a computer. CNC is a critical aspect of CAM in which a computerized controller uses motors to drive each axis of a machine such as a mill to manufacture parts in a production environment. The motors of the machine rotate based on the direction, speed, and length of time that is specified in the CNC program file. This file is created by a programmer and contains programming language used to establish the operation performed on the machine tool. Examples of CNC programming language include G-codes, which are primary functions such as tool moves, and M-codes, which are miscellaneous functions such as tool changes and coolant settings. CNC is a major innovation in manufacturing. CNC has to lead to increased productivity because the consistency of the process has lowered manufacturing costs, increased product quality, and led to the development of new techniques. Persons possessing skills in CADD and CNC can find a variety of opportunities in manufacturing industries.
Computer-Integrated Manufacturing (CIM)
Computer-integrated manufacturing (CIM) brings together all the technologies in a management system, coordinating CADD, CAM, CNC, robotics, and material handling from the beginning of the design process through the packaging and shipment of the product. The computer system is used to control and monitor all the elements of the manufacturing system. The figure illustrates an example of CAD within a CIM process. The field of CIM incorporates the disciplines of CAD, CAM, robotics, electronics, hydraulics, pneumatics, computer programming, and process control. Computer-integrated manufacturing enables all persons within a company to access and use the same database that designers and engineers would normally use.
Within CIM, the computer and its software control most, if not all, portions of manufacturing. A basic CIM system can include transporting the stock material from a holding area to the machining centre that performs several machining functions. From there, the part can be moved automatically to another station where additional pieces are attached, then on to an inspection station, and from there to shipping or packaging.
In addition to design and manufacturing, CADD provides usable data and supports many other areas of the engineering design process. Most sales and marketing materials, technical publications, and training documents reference some form of CADD data. Often existing drawings and models provide the majority of critical content required for items such as product brochures and installation and service manuals. Technical illustration involves the use of a variety of artistic and graphic arts skills and a wide range of media in addition to pictorial drawing techniques. The figure shows an example of a technical illustration partly created by directly reusing existing CADD data from the design process.