Computer-aided manufacturing (
CAM) is the use of
computer softwareComputer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....
to control
machine toolA machine tool is a machine, typically powered other than by human muscle , used to make manufactured parts in various ways that include cutting or certain other kinds of deformation...
s and related machinery in the
manufacturingManufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...
of workpieces. This is not the only definition for CAM, but it is the most common; CAM may also refer to the use of a computer to assist in all operations of a manufacturing plant, including planning, management, transportation and storage. Its primary purpose is to create a faster production process and components and tooling with more precise dimensions and material consistency, which in some cases, uses only the required amount of raw material (thus minimizing waste), while simultaneously reducing energy consumption.
CAM is a subsequent computer-aided process after
computer-aided designComputer-aided design , also known as computer-aided design and drafting , is the use of computer technology for the process of design and design-documentation. Computer Aided Drafting describes the process of drafting with a computer...
(CAD) and sometimes
computer-aided engineeringComputer-aided engineering is the broad usage of computer software to aid in engineering tasks. It includes computer-aided design , computer-aided analysis , computer-integrated manufacturing , computer-aided manufacturing , material requirements planning , and computer-aided planning .- Overview...
(CAE), as the model generated in CAD and verified in CAE can be input into CAM software, which then controls the machine tool.
Overview
Traditionally, CAM has been considered as a
numerical controlNumerical control refers to the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone...
(NC) programming tool, wherein two-dimensional (2-D) or three-dimensional (3-D) models of components generated in CAD software are used to generate
G-codeG-code is the common name for the most widely used computer numerical control programming language, which has many implementations. Used mainly in automation, it is part of computer-aided engineering. G-code is sometimes called G programming language...
to drive computer numerically controlled (CNC) machine tools. Simple designs such as bolt circles or basic contours do not necessitate importing a CAD file.
As with other “Computer-Aided” technologies, CAM does not eliminate the need for skilled professionals such as manufacturing engineers, NC programmers, or
machinistA machinist is a person who uses machine tools to make or modify parts, primarily metal parts, a process known as machining. This is accomplished by using machine tools to cut away excess material much as a woodcarver cuts away excess wood to produce his work. In addition to metal, the parts may...
s. CAM, in fact, leverages both the value of the most skilled manufacturing professionals through advanced productivity tools, while building the skills of new professionals through visualization, simulation and optimization tools.
History
The first commercial applications of CAM were in large companies in the automotive and aerospace industries for example
UNISURF UNISURF, developed by Pierre Bézier at Renault in 1971, was a pioneering surface CAD CAM system for car body design and tooling....
in 1971 at
RenaultRenault S.A. is a French automaker producing cars, vans, and in the past, autorail vehicles, trucks, tractors, vans and also buses/coaches. Its alliance with Nissan makes it the world's third largest automaker...
for car body design and tooling.
Historically, CAM software was seen to have several shortcomings that necessitated an overly high level of involvement by skilled CNC machinists. Fallows created the first CAM software but this had severe shortcomings and was promptly taken back into the developing stage. CAM software would output code for the least capable machine, as each machine tool control added on to the standard G-code set for increased flexibility. In some cases, such as improperly set up CAM software or specific tools, the CNC machine required manual editing before the program will run properly. None of these issues were so insurmountable that a thoughtful engineer or skilled machine operator could not overcome for prototyping or small production runs; G-Code is a simple language. In high production or high precision shops, a different set of problems were encountered where an experienced CNC machinist must both hand-code programs and run CAM software.
Integration of CAD with other components of CAD/CAM/CAE
Product lifecycle managementIn industry, product lifecycle management is the process of managing the entire lifecycle of a product from its conception, through design and manufacture, to service and disposal...
(PLM) environment requires an effective
CAD data exchangeCAD data exchange involves a number of software technologies and methods to translate data from one Computer-aided design system to another CAD file format...
. Usually it had been necessary to force the CAD operator to export the data in one of the common data formats, such as
IGESThe Initial Graphics Exchange Specification is a file format which defines a vendor neutral data format that allows the digital exchange of information among Computer-aided design systems....
or
STLSTL is a file format native to the stereolithography CAD software created by 3D Systems. This file format is supported by many other software packages; it is widely used for rapid prototyping and computer-aided manufacturing. STL files describe only the surface geometry of a three dimensional...
, that are supported by a wide variety of software.
The output from the CAM software is usually a simple text file of G-code, sometimes many thousands of commands long, that is then transferred to a machine tool using a
direct numerical controlDirect numerical control , also known as distributed numerical control , is a common manufacturing term for networking CNC machine tools...
(DNC) program.
CAM packages could not, and still cannot, reason as a machinist can. They could not optimize toolpaths to the extent required of mass production. Users would select the type of tool, machining process and paths to be used. While an engineer may have a working knowledge of g-code programming, small optimization and wear issues compound over time. Mass-produced items that require machining are often initially created through casting or some other non-machine method. This enables hand-written, short, and highly optimized g-code that could not be produced in a CAM package.
At least in the United States, there is a shortage of young, skilled machinists entering the workforce able to perform at the extremes of manufacturing; high precision and mass production. As CAM software and machines become more complicated, the skills required of a machinist or machine operator advance to approach that of a computer programmer and engineer rather than eliminating the CNC machinist from the workforce.
Typical areas of concern:
- High Speed Machining, including streamlining of tool paths
- Multi-function Machining
- 5 Axis Machining
Multiaxis machining is a manufacturing process, where computer numerically controlled tools that move in 4 or more ways are used to manufacture parts out of metal or other materials by milling away excess material, by water jet cutting or by laser cutting...
- Feature recognition
The term "feature" does not imply the same meaning in different engineering disciplines. This has resulted in several ambiguous definitions for feature. A feature, in computer-aided design software, can be called a region of a part with some interesting geometric or topological patterns...
and machining
- Automation of Machining processes
- Ease of Use
Overcoming historical shortcomings
Over time, the historical shortcomings of CAM are being attenuated, both by providers of niche solutions and by providers of high-end solutions. This is occurring primarily in three arenas:
- Ease of use
- Manufacturing complexity
- Integration with PLM and the extended enterprise
Ease in use
- For the user who is just getting started as a CAM user, out-of-the-box capabilities providing Process Wizards, templates, libraries, machine tool kits, automated feature based machining and job function specific tailorable user interfaces build user confidence and speed the learning curve.
- User confidence is further built on 3D visualization through a closer integration with the 3D CAD environment, including error-avoiding simulations and optimizations.
Manufacturing complexity
- The manufacturing environment is increasingly complex. The need for CAM and PLM tools by the manufacturing engineer, NC programmer or machinist is similar to the need for computer assistance by the pilot of modern aircraft systems. The modern machinery cannot be properly used without this assistance.
- Today's CAM systems support the full range of machine tools including: turning
Turning is the process whereby a single point cutting tool is parallel to the surface. It can be done manually, in a traditional form of lathe, which frequently requires continuous supervision by the operator, or by using a computer controlled and automated lathe which does not. This type of...
, 5 axis machining and wire EDM. Today’s CAM user can easily generate streamlined tool paths, optimized tool axis tilt for higher feed rates and optimized Z axis depth cuts as well as driving non-cutting operations such as the specification of probing motions.
Integration with PLM and the extended enterpriseLM to integrate manufacturing with enterprise operations from concept through field support of the finished product.
- To ensure ease of use appropriate to user objectives, modern CAM solutions are scalable from a stand-alone CAM system to a fully integrated multi-CAD 3D solution-set. These solutions are created to meet the full needs of manufacturing personnel including part planning, shop documentation, resource management and data management and exchange. To prevent these solutions from detailed tool specific information a dedicated tool management
Tool management is needed in the metalworking so that the information regarding the tools on hand, can be uniformly organized and integrated in the manufacturing environment and process flow. The information is stored in a database and is registered and applied using the tool management software...
solution for CNC production and shop floor requirements is implemented.
Machining process
Most machining progresses through four stages, each of which is implemented by a variety of basic and sophisticated strategies, depending on the material and the software available. The stages are:
Roughing
- This process begins with raw stock, known as billet
Semi-finished casting products are intermediate castings produced in a foundry that need further processing before being a finished good. There are four types: ingots, billets, blooms, and slabs.-Ingot:...
, and cuts it very roughly to shape of the final model. In milling, the result often gives the appearance of terracesTerraces are used in farming to cultivate sloped land. Graduated terrace steps are commonly used to farm on hilly or mountainous terrain. Terraced fields decrease erosion and surface runoff, and are effective for growing crops requiring much water, such as rice...
, because the strategy has taken advantage of the ability to cut the model horizontally. Common strategies are zig-zag clearing, offset clearing, plunge roughing, rest-roughing.
Semi-finishing
- This process begins with a roughed part that unevenly approximates the model and cuts to within a fixed offset distance from the model. The semi-finishing pass must leave a small amount of material so the tool can cut accurately while finishing, but not so little that the tool and material deflect instead of shearing. Common strategies are raster passes
Raster passes are the most basic of all machining strategies for the finishing or semi-finishing of a part during computer-aided manufacturing . In raster passes machining the milling cutter moves along curves on the cutter location surface obtained by intersecting the CL surface with vertical,...
, waterline passes, constant step-over passes, pencil millingPencil milling is a cleanup toolpath generated by computer-aided manufacturing programs to machine internal corners and fillets with smaller radius tools to remove the remaining material that are inaccessible with larger tools used for previous roughing, semi-finishing, and finishing toolpaths...
.
Finishing
- Finishing involves a slow pass across the material in very fine steps to produce the finished part. In finishing, the step between one pass and another is minimal. Feed rates are low and spindle speeds are raised to produce an accurate surface.
Contour milling
- In milling applications on hardware with five or more axes, a separate finishing process called contouring can be performed. Instead of stepping down in fine-grained increments to approximate a surface, the workpiece is rotated to make the cutting surfaces of the tool tangent to the ideal part features. This produces an excellent surface finish with high dimensional accuracy.
Software
The top 20 largest CAM software products and companies, by vendor revenues in year 2009 are, sorted alphabetically:
- BOBCAD-CAM from BobCAD-CAM
- CATIA
CATIA is a multi-platform CAD/CAM/CAE commercial software suite developed by the French company Dassault Systemes...
from Dassault SystèmesDassault Systèmes S.A. is a leading company specializing in 3D and PLM software.Dassault Systèmes develops and markets PLM application software and services that support industrial processes and provide a 3D vision of the entire lifecycle of products from conception to maintenance to recycling...
- CAM-Tool from C & G Systems
- CimatronE from Cimatron
Cimatron Group is one of the largest CAD/CAM software developers worldwide, offering manufacturing, toolmaking and CNC programming solutions. Founded in 1982, Cimatron is listed on the Nasdaq and Tel Aviv Stock Exchange under the symbol CIMT...
Group
- Dynavista from Nihon Unisys
- Edgecam from Planit
- Esprit from DP Technoogy
- GibbsCAM
GibbsCAM is a computer-aided manufacturing program developed by Gibbs and Associates , a division of Cimatron Group. GibbsCAM specializes in providing a powerful range of CNC programming functionality. The software is intended to be familiar to machine shop personnel...
from CimatronCimatron Group is one of the largest CAD/CAM software developers worldwide, offering manufacturing, toolmaking and CNC programming solutions. Founded in 1982, Cimatron is listed on the Nasdaq and Tel Aviv Stock Exchange under the symbol CIMT...
- HyperMill from Open Mind
Open Mind may refer to:* Open Mind , 1984 album by Jean-Luc Ponty* Open Mind , American Champion racehorse* Keep Your Mind Wide Open, a 2007 song by AnnaSophia Robb* The Open Mind, a long-running public affairs talk show...
- Mastercam from CNC Software
- NX from Siemens PLM Software
Siemens PLM Software is a computer software company specializing in 3D & 2D Product Lifecycle Management software. The company is a business unit of Siemens Industry Automation division, and is headquartered in Plano, Texas....
- PowerMILL from Delcam
Delcam is one of the world's leading suppliers of advanced CAD/CAM software product development solutions for the manufacturing industry. The company has grown steadily since being founded formally in 1977, after initial development work at Cambridge University, UK...
- Pro/E from PTC
Parametric Technology Corporation is a U.S.-based company that develops, markets and supports software for product development. Its main products are for CAD/CAM, engineering calculations, and product lifecycle management. Its customers include companies in manufacturing, publishing, services,...
- SolidCAM
SolidCAM provides CNC manufacturing customers with a full suite of CAM software modules for 2.5D Milling, High Speed Surface milling, 3D Milling/High-Speed Machining, Multi-sided Indexial 4/5 axes Milling, Simultaneous 5 axes Milling, Turning, Turn-Mill and WireEDM.SolidCAM's latest iMachining...
from SolidCAMSolidCAM provides CNC manufacturing customers with a full suite of CAM software modules for 2.5D Milling, High Speed Surface milling, 3D Milling/High-Speed Machining, Multi-sided Indexial 4/5 axes Milling, Simultaneous 5 axes Milling, Turning, Turn-Mill and WireEDM.SolidCAM's latest iMachining...
- Space E from NTTD
- SurfCAM from Surfware
Surfware, Inc. is a Camarillo, CA-based company dedicated to innovation and development of CAD/CAM software. In 1950, Victor Diehl opened a mold shop in Southern California for machine tooling medical products. Throughout the 1950s, Victor Diehl focused on precision mold products for the medical...
- TopCAM from Missler
- Tebis
Tebis is a CAD/CAM program supplied by Tebis Technische Informationssysteme AG headquartered in Martinsried near Munich/Germany.- Facts and figures :...
from Tebis AG
- VisiCAM from Vero
Vero may refer to:* Véro, a 2005-2006 talk show on the Radio-Canada television network* Vero Beach, Florida* Vero, Corse-du-Sud, a commune of France in Corsica* Vero cell* Vero Software Plc* Vero in Aragon, Spain...
- Vericut from CGtech
- WorkNC
WorkNC is a Computer aided manufacturing software developed by Sescoi for 2, 2.5, 3, 3+2 and 5-axis machining. WorkNC is well known for having always focused on automation and ease of use since its first release in 1988. WorkNC-CAD was introduced in 2002, making WorkNC a complete CAD/CAM product,...
from SescoiSescoi is a developer of industrial software for computer-aided manufacturing, enterprise resource planning and extended enterprise productivity. Its WorkNC software is one of the market leaders in the CAD/CAM field and is used by more than 25% of companies in demanding countries such as Japan...
See also
- Computer-integrated manufacturing (CIM)
- Direct numerical control
Direct numerical control , also known as distributed numerical control , is a common manufacturing term for networking CNC machine tools...
(DNC)
- Flexible manufacturing system
A flexible manufacturing system is a manufacturing system in which there is some amount of flexibility that allows the system to react in the case of changes, whether predicted or unpredicted...
(FMS)
- Integrated Computer-Aided Manufacturing
Integrated Computer-Aided Manufacturing is a US Air Force program to develop tools, techniques, and processes to support manufacturing integration and has influenced the computer-integrated manufacturing and computer-aided manufacturing project efforts of many companies.The ICAM program was...
(ICAM)
- Manufacturing process management
Manufacturing process management is a collection of technologies and methods used to define how products are to be manufactured. MPM differs from ERP/MRP which is used to plan the ordering of materials and other resources, set manufacturing schedules, and compile cost data.A cornerstone of MPM is...
(MPM)
- STEP-NC
STEP-NC is a machine tool control language that extends the ISO 10303 STEP standards with the machining model in ISO 14649, adding geometric dimension and tolerance data for inspection, and the STEP PDM model for integration into the wider enterprise...
- Rapid prototyping
Rapid prototyping is the automatic construction of physical objects using additive manufacturing technology. The first techniques for rapid prototyping became available in the late 1980s and were used to produce models and prototype parts. Today, they are used for a much wider range of applications...
and rapid manufacturing - solid freeform fabrication direct from CAD models
External links