If you are involved with CNC machines, you are probably involved with CNC programming and CAD/CAM systems. The biggest change in recent times for the CAD/CAM industry lies with the term "integration". Integration plays a very important role in the future of CAD/CAM products. There have been big workstation integrated CAD/CAM systems around for many years. They provide CAD and CAM integration by providing all pieces from the same company.
Now there is a new group of products touting integration as a key issue. They pursue integration through other means than single brand products. What is CAD/CAM integration? Is it good? Do you need it? It all depends on the type of integration and what your needs are. To understand CAD/CAM integration today, it makes sense to start with the steps that need to be integrated.
CAD (Computer Aided Design) is widely used to describe any software capable of defining a mechanical component with geometry, surfaces, or solid models. CAM is software used to develop NC programs. There are other types of CAD and CAM, but for the purposes of this article, only mechanical CAD and CAM are discussed.
Engineering design and manufacturing uses CAD/CAM software for three distinctly different purposes:
Design Modeling. A mechanical design engineer uses CAD software to create a part. This definition of the part can be called its model. This model can be represented as a drawing or a CAD data file. (fig.1)
Manufacturing Modeling. A manufacturing engineer or NC programmer, uses CAD software to:
- Develop a computer model of a part that was defined by a drawing.
- Evaluate and repair the design CAD data to manufacturing tolerances. This is a surprisingly common task.
- Create new part models from the original design to allow for manufacturability. This would include adding draft angles or developing models of the part for different steps in multi-process manufacturing.
- Design models of fixtures, mold cavities, mold cores, mold bases, and other tooling. (figs. 2 & 3)
NC Programming. A manufacturing engineer or NC programmer uses CAM software to select tools, methods, and procedures to machine the models defined in the manufacturing modeling section described above. Note that the user that performs manufacturing modeling is usually the same user that performs NC programming. (4 & 4a).
In a perfect world, you would select up to three different products, each one best at one of these functions, and they would all interact perfectly. Unfortunately this is not a perfect world. For these different products to work well together, they need to possess a high level of integration. Integration refers to how different software functions work together. There are three different types of integration to consider:
Data Integration. Data integration is the ability to share part models (common data files or a common database). This is the most important type of integration for CAD/CAM. An IGES surface file represents poor data integration, due to the amount of manual repair work frequently required for success. (See picts 5 & 6) A Parasolid file sent from one Parasolid based software program to another, represents very good data integration, as the data comes through flawlessly. (See pict 7) Two Parasolid based software programs sharing one Parasolid data file is even better, as both model history and associativity can be maintained.
Application Integration. Application integration is the way in which different modules work together for a single user. This can be achieved by having the different functions physically in the same computer program ("same" application or "inside" application integration). It can also be achieved with technology like OLE, which allows two different computer programs to work closely together, appearing seamless to the user (CAM "beside" CAD).
How Integration Started
In the beginning, there were only CAD systems. Engineers used CAD systems to draw pictures of parts. The first CAM systems helped an NC programmer/machinist/manufacturing engineer program from these drawings. This making of drawings, and programming parts from drawings, was (and still is) time consuming and subject to a lot of human error. Someone got the bright idea to eliminate this to-and-from drawing step, and integrated CAD/CAM was born.
Until recently, integrated CAD/CAM meant buying the same brand CAD and CAM products. Many companies provide such products today. Companies like Parametric Technologies (Pro/E and Pro/Manufacturing), Unigraphics, Dassault (Catia), SDRC (IDEAS), Computervision (CADDS 5), and others. All provide high sophistication, high power, and high cost solutions. These products typically provide data, interface, and application integration. Because of their cost and complexity, these products do not provide ideal solutions for everyone. In addition, once the customer picks the CAD product he likes best, he’s kind of stuck with whatever CAM product they have. No mixing and matching of products is allowed.
The disadvantages of the traditional integrated workstation CAD/CAM system has contributed to the growth of the standalone CAM market as we know it today. These CAM products focus on NC programming, or both manufacturing modeling and NC programming. In general they are faster, easier, and far less expensive than their workstation-based integrated brethren. This class of products has grown in sophistication to rival the capabilities of the traditional integrated CAD/CAM products, while maintaining their lead in simplicity, efficiency, and cost. The only problems they have suffered from is a lack of integration with the original design modeling CAD system, and a lack of ability to access the CAD market. Now that is changing.
The New CAD Market
The PC has been home to CAD software for decades. This CAD software has been primarily 2D drafting and 3D wireframe CAD, with a few surface modeling products, such as Autocad. While a success story in its own right, Autocad, and products like it, have never made the step up to providing significant competition to the workstation CAD market. Things have changed in recent times.
It all started with Windows NT and fast PCs like the Pentium Pro, helped along by low priced RAM. Workstation CAD users began to envy the low purchase cost, low maintenance cost, ease of use, ease of networking, and performance of the new PC’s. (Not faster then a workstation yet, but an excellent price vs. performance). It didn’t take long before someone realized these PCs were now capable of running the same solid modeling technology used in the major workstation CAD products.
Unix has 62% of the CAD/CAM market in 1997, down from 67% in 1996. Window NT is estimated to have 23% of the CAD/CAM market in 1997, up from 17% in 1996. The total number of Unix seats grew 9%in 1997. The total number of Windows seats grew 59% in 1997#. (See chart) With a massive difference in growth rates, UNIX is rapidly being overtaken by Windows NT as the dominate CAD/CAM platform.
Another key change in the CAD/CAM market is the advent of the third party solid modeler. Solid modeler kernel companies like Spatial Technologies (ACIS), EDS (Parasolid), and Ricoh (Designbase) began selling to solution providers who started focusing on the mid-range CAD market. In 1995, SolidWorks and Intergraph SolidEdge were introduced and a new era of solid modeling CAD began. They weren’t alone for long. New product announcements have become common, with all major CAD companies jumping into this new market. Bentley introduced MicroStation Modeler. Parametric Technology renamed their Pro/E Jr. as PT Modeler to better be perceived as a mid-range CAD player. Computervision introduced DesignWave, and was purchased by PTC. SDRC introduced their Artisan series and purchased Camax to provide CAM technology. Dassault (Catia) has announced their intent to field a Windows NT product and recently purchased SolidWorks. Not only does solid modeling technology fuel the rapid growth of new products, but it also provides a backbone for seamless data transport between compatible products.
CAM in the new CAD Market
CAM products are also moving into this solid modeling CAD world. Some CAM products have plotted the shortest possible path to a marketing claim of "solids-based solution". In several cases, this path has lead to an "inside" CAD application version of their product, where the product’s CAM capabilities are actually placed within the CAD software. This, however, can lead to a very limited set of CAM capabilities, not nearly the full feature set of the standalone versions.
There is another alternative. Any CAD or CAM product based on the same modeler (solid modeling kernel) can exchange data as well as the big workstation systems do, providing a high level of data integration between different brand of products, for the first time. (See picts 8, 9 & 10) Solid model standards include Spatial Technologies’ ACIS (.sat files) and Parasolid (.x_t and .xmt files) and Ricoh’s Designbase. These standards are becoming widely supported.
Fig. 9 (right): A core created from the above mentioned SolidWorks part. The data integration between the products provides high levels of integration.
OLE (and OLE for D & M) is another Windows technology becoming popular. This capability allows a CAM product to directly "ask" a CAD system for model data, without the hassles of saving and opening files, or the technical problems of file translations. It is another powerful tool for providing data and application integration.
Historically all CAD/CAM solutions offering high levels of integration have achieved it by putting all functions in the same computer program. This is one reason why some people think that there are big advantages with same application integration for CAD/CAM. Today’s technology provides flexible alternatives to the old same application approach. Solid models and OLE provide excellent integration between different applications. Windows NT/95 offers excellent interface integration.
Who needs Integration?
Everybody. To illustrate the different types of needs, consider three classes of users:
Job Shops. A job shop machines other people’s designs, created on other people’s CAD systems. A job shop does not have a primary design modeling CAD need, and therefore derives little value from interface or application integration with other people’s CAD systems. Data integration with other people’s CAD systems is very valuable, and a prime concern. Job shops have to deal with a wide variety of data types from a variety of sources. The ability to import and repair data from many sources is vital. A job shop needs manufacturing modeling and CAM capabilities.
Small Integrated Manufacturing sites. The small integrated manufacturing company, for the purposes of this paper, is defined as a company where one person is doing the primary product design modeling, the manufacturing modeling, and the NC programming, on a single computer. Like the job shop, data ntegration between the products is the most important issue. In addition, the user gets advantages from application and interface integration with his CAD product.
General Manufacturing sites. These manufacturing companies have separate individuals performing design modeling, manufacturing modeling, and CAM, or in most cases have entirely different departments. These companies range from job shop like departments supporting a wide range of internal CAD formats, to departments that utilize the same CAD as the design department, for maximum integration. Data integration is the common issue.
How To Decide What’s Right For You
The first step in deciding what is right for your shop is to understand that you now have options. You are no longer trapped in to buying an large, expensive, workstation CAD/CAM system if it is not right for your needs. Nor do you have to settle for less than adequate data translations from standalone products. Examine your needs. Do you get most of your CAD files from a variety of sources? Or, do you receive CAD files from primarily a single source? Then look around for the CAD and CAM products that fit the needs of your shop best -- focusing on ease of use and suitability to the type of work that you do. Armed with the facts and the new capabilities available to you, you are ready to make an informed choice.