Gains in profitability can come from willingness to rethink production methods. Keller Engineering, of Torrance, California, has improved profitability through the use of CNC (computer numerical control) machines, computer-aided manufacturing, rotary indexing tables and imaginative fixturing. The gradual adaption of new capabilities in these areas has made the company increasingly competitive and allowed for continued expansion.

Keller now has six OKK vertical mills, two OKK horizontal mills using Meldas controls, and one Matsuura vertical mill with a Yasnac control. They also have one Nakamura and two Ikagami lathes with Fanuc controls. Although most of the mills are capable of three-axis simultaneous machining, this capability is not extensively used. Their primary focus has been on parts that require machining on several surfaces. For this reason, Mark Scott, CNC programmer, has concentrated on building fixtures that eliminate repetitive setups.

For example, there was one part that required seven setups and 20 cutting tools, and involved machining on five surfaces in six different orientations. Mr. Scott made significant improvements in the overall cycle time by adding a “tombstone-type” fixture mounted on a rotary table. It held twelve parts and needed only one setup to complete the part. The indexing table cost over, $8,000, but the cost savings on this one job paid for it.

The benefits of this investment in terms of reduced setup costs were substantial (more than 80 percent) but additional improvements in accuracy were significant. In the past, when parts were moved to a second or subsequent operation, it was more difficult to hold tolerances. But with the elimination of this variability, the accuracy of the parts substantially improved. As would be expected, material waste was practically eliminated.

The success of this addition led to the purchase of rotary tables for all of the six vertical mills and indexing tables for the horizontal mills. The expansion of these production capabilities in the form of a fourth axis for each machine meant more time spent in part programming. At this point, Albert Keller, founder, and Mr. Scott began to look for a CAM system to assist in part program generation.

New System

An earlier system had reached the limits of its capabilities. Mr. Scott was aware of the advances in microcomputer-based CAD/CAM, so he undertook an investigation of these more affordable systems. Recent shows, articles, and advertisements had indicated extensive software offerings. Several of the more promising systems were investigated, and some were tried in-house for a period of time. This was done to determine what program features would be truly helpful in practice. Most of the work at Keller is based on 2 1/2-axis machining. Several roughing passes are required on almost every part. The ability to create a variety of roughing routines quickly was a primary function. Spiral roughing, from the center outward in particular, is important when using aluminum. Many parts have islands and bosses that require more complicated tool paths. Combining this with the rotation of the fixture makes programming even more complex.

There was a lot of variety in the programming systems they considered. They varied from CAD-type data input with automatic dimensioning to unlimited post processors. Keller’s final criteria, though, was how quickly they could get the code for the tool path they wanted in the needed format. They decided on the SmartCAM Integrated CAM system from Point Control Co., 2468 W. 11th Ave., Eugene, Oregon 97402, with 3D machining capabilities.

The software has features that help create the complete tool path, especially where the geometry becomes complex with multiple tools. The roughing capabilities are very extensive and meet specific needs. Another important feature is the ability to mask off various segments of the tool path or other geometry when the programmer wants to work with only certain sequences of the tool path. It is also possible to draw a complete tombstone fixture in 3D, position the parts on all sides and then develop a complete tool path with rotations included. At any point in the process, it is possible to see a simulation of the tool path with the actual tools drawn to specification (Figures 1 and 2).

Another factor was that a post processor package supporting the machines was included in the system. It was also able to be customized to meet the shop’s specific needs for each machine variation. Mark Scott has since made several modifications for minor differences. With the combination of the machining equipment and CAM system, Keller has been able to reduce costs by more than 50 percent on many individual parts. The average part has five tools and about a 15-minute cycle time. A typical workpiece program can be generated in about 20 minutes, from start to finish, so one workstation supports all 12 CNC machines.

Results

Keller now has many examples of how their automation has made them more productive. Typically, their customers provide them with drawings and the geometry is entered directly into the CAM system. As the part is drawn, the tool path is automatically created to make that part. When the programmer is finished putting in geometry, most of the work is done. Feeds, speeds, and machining sequences, of course, have to be indicated. For simple parts, learning time was relatively short. The complicated parts are where the system makes the biggest difference.

http://www.findarticles.com/p/articles/mi_m3101/is_n6_v63/ai_9117076

companies look to implement computer-aided process planning along with other manufacturing information systems, they will do well to scrutinize the needs of all system users.

One of the most important steps in converting a design concept into a manufactured product is process planning. The essence of that task is the creation of a complete package of information on how to perform the manufacturing process, which may include work instructions for the shop floor, a bill of material, a quality control plan, tool planning, and so on. Also, there may be links to other manufacturing systems such as MRP (material requirements planning), PDM (product data management), time standards, engineering and manufacturing change control, shopfloor control and data collection systems. In most cases, this initial package of information ultimately determines the final cost and quality of the product.

Traditionally, manufacturing engineers produced the necessary process planning documents from scratch using manual techniques. That required the retrieval and manipulation of a great deal of information from many sources including established standards, machinability data, machine capabilities, tooling inventories, stock availability and, hopefully, existing practice. The resulting process plan was then manifest in the form of printed text, lists and drawings.

The introduction of computers into manufacturing has certainly made the planning function more efficient, but there are additional advantages. For one, computers can readily perform vast numbers of comparisons and, therefore, many more alternative plans can be explored than would be practical in a manual setup. Also, the application of computers can bring greater uniformity to process planning. Ask ten engineers to develop a process plan for the same part, and you will probably end up with ten different plans. Not only does this mean some plans will be better than others, but also that essentially similar jobs planned at different times will be done differently. However, with the comparative capabilities brought about by computer-aided process planning (CAPP), it becomes easier to answer the questions: Which plan best utilizes the facility’s capabilities? Which can be used for estimating future work? Which is best for scheduling and shop loading? And most important, which plan reflects the best practice based on past experience?

While CAPP can indeed answer these questions, to be of optimum value, particularly in larger manufacturing facilities, companies must carefully consider its implementation and integration with other systems. Here are some factors to think about if CAPP is to achieve its potential.

Sorting Parts

CAPP got its start with Group Technology (GT), which was touted as a solution to manufacturing in an environment of smaller lots and shorter product life cycles. The underlying principle of GT is relatively simple: Use a well-structured coding and classification system to identify similar components and processes. Then once “families of parts” are identified, they can be manufactured with standardized process plans.

Early CAPP systems were based on this general principle, and still are, though there are now basically two approaches to how systems work - variant and generative. In the variant approach, a set of standard process plans is established for all the parts families identified through GT. Then when a new plan is required, an applicable standard plan is retrieved and edited to suit the specific requirements of the new part.

In the generative approach, an attempt is made to synthesize each individual part using appropriate algorithms that define the various technological decisions that must be made in the course of manufacturing. In a truly generative system, the sequence of operations as well as all the process parameters would be established automatically, without reference to prior plans. The costs of setting up such a system are so high, however, that so-called generative process planning systems have been developed only for specific operations - selection of feeds and speeds, for example - or for uniform families of similar parts.

Although some early CAPP systems contained elaborate classification and retrieval capabilities, coding all parts in a typical manufacturing environment proved to be unrealistic. It was simply too tedious, time-consuming and expensive. And in time, many of these systems were used primarily as word processors with some retrieval of standard texts. Nevertheless, this was a great improvement over the old ways of paper-driven process planning. It simply lacked the sophisticated retrieval and modification capabilities of a modern CAPP system.

The Power Of Integration

Also critical to the capabilities of today’s CAPP is the ability to integrate with other data-management systems. A host of computer based technologies - such as CAD, CAM, CNC, CAPP and statistical QC - all have the potential for optimizing the manufacturing process, but only if they are used to reduce redundancy and to learn from our past mistakes.

Early attempts to execute this integration were carried out on mainframe computers, and with a great deal of custom software, often developed by the users themselves. The trend now, however, is toward distributed processing in a network environment and “COTS” (commercial off-the-shelf software). Still, every company wants its own bells and whistles and various print routines or screen displays geared to the presentation requirements of its departments. Therefore, to be effective, a so-called COTS CAPP system must have the capability of being tailored to specific interface and output requirements. One way of achieving such flexibility is to incorporate a macro language that enables the installer to fine tune the system without having to alter the underlying software code.

Learning From Past Mistakes

One of the pitfalls of applying new computer-based technologies is that they make it easier to come up with new designs and methods but not necessarily those that are the most efficient for a particular manufacturing environment. Some may argue that starting from scratch with a clean design and a fresh manufacturing plan will more likely ensure everything is done correctly. However, starting from scratch can result in part designs that are functionally interchangeable but with widely varying manufacturing costs due to differences in tolerances and materials.

In fact, it has become increasingly apparent that when a new product is designed, roughly 80 percent of its parts are either the same or similar to parts already developed for other products. To reinvent these parts from scratch is a waste of effort no matter how fast and easily it can be done. Moreover, this approach increases the likelihood of mistakes sneaking through to the later stages of production because the new design or plan never went through the rigors of the manufacturing process. For these reasons, effective retrieval of existing manufacturing experience becomes essential.

Taming GT

GT often requires an analysis of 2,000 to 3,000 parts before the total of code numbers needed to represent all part families starts to level off. However, part families really represent combinations of basic part features such as holes, slots or pockets, and the number of features represented at any one company is usually quite limited. Furthermore, process plans are determined by part features, not part families.

In fact, most company divisions deal with somewhere between 20 to 30 different features, which usually can be flushed out by analyzing between 100 and 200 randomly selected parts. Each feature, in turn, has a small number of manufacturing methods associated with it - about 15 methods on average, depending on feature size, material and tolerance. This means that most companies deal with no more than 500 distinct manufacturing methods, which is a very manageable number for retrieval purposes.

The AI Factor

What about artificial intelligence? At the end of the 1980s you could barely sell a CAPP system without offering a rule-based generative capability. But actual use of this capability has been minimal. At a conference of some 60 U.S. and European companies sponsored by Houtzeel Manufacturing Systems in 1991, the application of AI in CAPP was explored. Several participants had invested substantial efforts in the development of AI-based generative process planning systems. But all had come to the conclusion that such systems, though technically feasible, provide unacceptably low returns on investment, particularly in dealing with general detail parts or assembly operations.

However, where groups of similar parts or assembly operations are concerned, such as the manufacture of turbine blades, they determined an AI-based system could be profitable. In other words, a global application of AI to provide generative process planning for the entire universe of parts manufactured by a company is unrealistic. However, using GT analysis, it is possible to arrive at a limited number of part families where an expert system can be cost effective.

Needed: Manufacturing Information Management

It becomes increasingly important to implement a manufacturing infrastructure compatible with today’s installed computer networks of mainframes, workstations and PCs to provide access to the many heterogeneous systems. Those systems may serve such diverse activities as CAD, CAM, MRP, SPC, tool management and work time measurement.

To be effective, such a manufacturing information system must be able to create, check and deliver information in a seamless and user-friendly manner, preferably employing a common user interface. The system must be capable of creating and delivering information in a number of ways - whether designs and process plans are created from scratch, or with generative or variant approaches - including

* Product or process designs or sketches,

* Optimized process instructions,

* Access to information to all related areas such as toolroom, shop floor, QC and so on,

* Delivery of process plan in printed or electronic form,

* Management of engineering and manufacturing revisions,

* Work assignment,

* Manufacturing bill of material, effectivity (the selective application of engineering change orders), and where-used.

As manufacturing information is created, it must be made available to all affected parties for concurrent review, and that review process should be properly documented. Moreover, the delivery of information among the various players in the manufacturing cycle should be tailored to their individual needs and expectations. While the manufacturing engineer may compose a complete process planning package including tool, QC, work instructions, and so on, the machine tool operator may require, among other things, a very detailed setup plan that includes graphics, digital photos or video, NC programs and data, or inspection programs and instructions.

Finally, and most important, the system must provide an effective feedback mechanism. It is not sufficient that information flows only from the top down, or that it consists solely of instructions to the next phase in the manufacturing cycle. People at each node in the manufacturing network must be able to annotate the information they receive with appropriate comments reflecting their experience and know-how and pass it back among the affected parties. As an example, red-lining (the electronic attachment and tracking of relevant notes) between manufacturing and design engineering can be used to help ensure that an emerging design is compatible with the best available manufacturing processes.

Or, when sections of the entire process planning package are disseminated to different manufacturing groups, a feedback mechanism should be in place to signal errors or the potential for better practices to the process planner. This way the information system is continuously updated, which makes future retrieval more relevant. Continuous improvement becomes a reality.

Uniform User Interface

In the use of earlier mainframe-based systems, highly trained engineers tended to specialize in particular tasks such as process planning, bills of material, and so on. But today’s manufacturing engineers are required to perform all these tasks, and more efficiently. Consequently, it becomes important that the user interface be similar or the same for all these tasks in order to reduce learning time and errors. Some companies are now insisting that all functions within the manufacturing information handling system employ the same user interface for functions as diverse as engineering and manufacturing change orders, configuration control, process planning, bills of material, tool management, time standards, shop floor control and data collection, shopfloor access and feedback, and quality control.

Considering this wide range of activities, it only makes sense that uniform user interfaces can substantially improve user efficiency and reduce errors.

PDM And MRP Alone Won’t Do

However, as companies implement PDM and MRP systems, the need to address the requirements of manufacturing information management often gets lost in the shuffle. Management tends to divide company activities into two major functions - design and production - and not three, so the manufacturing engineering function is generally treated as a secondary issue. The reality is that the manufacturing information handling function is far more complex and important to the success of a company than top management realizes.

Management tends to assume that PDM and MRP can provide all necessary manufacturing information, but in fact neither can provide appropriate access for developing and updating entire process planning packages. For example, MRP systems may provide process planning capabilities but they do not typically have the manufacturing information handling capacity or integration with the graphics capabilities now seen in modern CAPP systems.

Or, as another example, PDM databases are developed according to engineering features and therefore are not necessarily relevant to manufacturing considerations. Functionality or part features are the key factors governing the structure of a product-oriented database while the process planner deals with manufacturing elements and processes such as tools and fixtures, turning, milling, hardening, and so on. So when companies suggest that they intend to maintain one overall product database developed from an engineering/design point of view, they overlook manufacturing engineering’s need for access to past manufacturing experience that is so essential to the continuous improvement process.

A critical issue, yet unresolved, is who should maintain authority over such a database. At present, PDM advocates insist that they are the appropriate agency to maintain and control the product information database and that any changes or updates must go through their approach. But unless the PDM system maintains an appropriate database where items can be searched for by engineering and manufacturing features, it is not possible to integrate the manufacturing function - and management’s vision of an overall product database becomes an illusion.

RELATED ARTICLE: What About The Hardware?

At present, the UNIX client/server approach best serves the need for a distributed network because it provides adequate security for the data by strictly controlling access. Different client/server approaches are available. For one, the database can reside on the server and the manufacturing information handling system software (such as CAPP) resides on individual workstations. Or, both the database and system software can reside on a larger server that is accessed with X-Window terminals. And in the near future, the system security of PCs may be sophisticated enough to have system software running on this platform with a database located on either a UNIX or PC server.

ALEXANDER HOUTZEEL President, HMS Software, Inc. Waltham, Massachusetts

http://www.findarticles.com/p/articles/mi_m3101/is_n6_v68/ai_18138836

Even though many software manufacturers tout their “interoperability,” end users are still dealing with disconnects among their CAD, CAM, and CNC systems. But this is quickly changing. In the not-too-distant future, industry-wide collaboration between software and CNC vendors will lead to more-complete data being shared throughout the design-through-manufacturing cycle. This, in turn, will lead to intelligent machine tools that process quality parts in less time.

Fortunately, over the years, integration and data sharing ( interoperability) between CAD and CAM products have come a long way. For instance, industry-standard file formats, such as the Initial Graphics Exchange Specification (IGES), are better supported, letting CAD geometry reliably transfer between CAD and CAM systems. Industry is also developing new standards, like the International Standards Organization’s (ISO) Standard for the Exchange of Product Model Data (STEP), to meet expanding interoperability requirements.

In addition, both CAD and CAM systems typically use solid-modeling kernels such as Parasolid and ACIS that not only allow transparent exchange of solid-model data, but also consistent interpretation of the data. And software libraries, which support reading geometry contained in native CAD-file formats, allow CAM systems to access CAD data without requiring the CAD software. Because of these advances, today’s manufacturers expect to be able to flawlessly read CAD geometry from almost any source.

Process-flow disconnects
Today’s jobshops typically shop for CAD/CAM software by either purchasing from a single-source supplier or building a solution from a number of best-in-class CAD and CAM products. Which they choose is often determined by price, dataintegrity concerns, and flexibility to deal with a variety of customer file formats. But the best solutions lend themselves to the following product/process flow:

1. Design CAD — used by the product design engineer.
2. Manufacturing CAD — employed by manufacturing engineers and CNC programmers to program parts designed by someone else.
3. CAM — defines machining strategies, order of operations, and the tooling used. It also generates machine-specific CNC programs.
4. CNC machine tools — run these programs to cut parts.

Today, designers use CAD to create new products. They then send the CAD file (wireframe or solid models, for example) to the manufacturing departments or jobshops. This CAD data, called a “nominal” model, gives CAM users the final geometry of the parts, but it does not include geometric dimensions, tolerances, or surface-finish information. Thus, the solid model contains the geometry but not all the information necessary to machine a part.

Unfortunately, design and manufacturing groups still communicate product-specification data through engineering drawings. Where CAM system functions could be boosted is by integrating the product specs with the solid model from the CAD system. As is, the CAM system doesn’t have all the information it needs. Hence, CAM users still have to import CAD geometry into their CAM systems and then read blueprints to completely understand what is to be machined.

A similar disconnect occurs between a CAM system and a CNC. G-code, currently the state-oftheart in CNC-program format, tells machine tools exactly where and how to move. But the machines never really make these perfect “nominal moves.” In reality, they just comes “close enough.” That’s because the physics of a CNC machine requires a small tolerance — in deviating from a corner, for example — so that the machine doesn’t come to a complete halt after every move.

Sophisticated CNCs handle axisservo acceleration and deceleration while following toolpath motion. But G-code from the CAM system does not specify tolerances or tell the CNC whether it is roughing, finishing, or cutting a surface or a solid. If it did, CNC manufacturers could build machines that cut parts faster, while still holding tolerances.

In addition, if CAM systems knew the accel/deaccel curves for specific machines, how controllers calculated path deviations, and how fast they processed blocks of G-code, they could better optimize toolpaths and accurately model tool motion and run times. In fact, having a complete understanding of a specific-machine tool’s configuration — including tools loaded in its tool changer and tolerances it can hold —would let a CAM system further tailor developing manufacturing strategies for faster run times and improved part quality.

Future CAD/CAM/CNC
Such opportunities cannot easily be acted upon by any single product vendor. That’s because the CAD product must include geometric dimensions and tolerances with other part-specification data and provide a way to access it. The CAM software, in turn, has to do something useful with this data. And information communicated from the CAM system to the machine tool must contain enriched data that lets the CNC intelligently process it.

Through a collaboration similar to that between CAD and CAM vendors, CAM software and CNC manufacturers will build next-generation capabilities to take advantage of this extended data. However, collaborations can be tough to realize.

Fortunately, the U.S. Government provides grants and funds programs for improving technologies. For instance, it supports projects for next-generation technologies such as STEP-NC. This ISO data format should extend CNC’s data-input format well beyond Gcode. Though still in the early stages of definition, STEP-NC shows much promise in providing process data to machine tools.

At the same time, various industry groups are working together to promote the development of nextgeneration machine tools.The Open Modular Architecture Controller (OMAC) consortium is defining a control architecture that integrates components from multiple sources, not just single-source, proprietary solutions. OMAC is also defining a standard human-machine interface for controllers. This will give a common interface for operators moving from machine to machine. Finally, the Smart Machine Platform Initiative (SMPI) project is defining a next-generation machine tool smart enough to ensure that the first cut part is correct.

http://www.americanmachinist.com/304/Issue/Article/False/8593/

Theorem Solutions is building on its new status as a Dassault CAA development partner through the application of its CADverter technology to provide new interoperability capabilities for CATIA V5 users. Theorem’s advanced data translation tools are paving the way for new functionality to support Dassault’s MultiCAD initiative which calls for interoperability to be in the hands of users, so that ‘design in context’ can be undertaken without the need for external translation of non CATIA V5 parts. Within the MultiCAD environment, CATIA V5 users are able to select a part or assembly in a third party format such as UGNX and cause it to appear as a node on their CATIA V5 design tree; either as a single component or full assembly, as appropriate.

Specification of the required components to be worked on automatically initiates the Theorem translation technology to bring the non CATIA data into the CATIA V5 session in the user’s desired CGR or Brep format, depending on the CATIA session settings.

This highly interactive method of operation not only benefits users working within the CATIA V5 MultiCAD strategy, as CATIA V5 also maintains and manages links with the imported files - enabling updated versions of them to be made available to the user if the original UGNX part or assembly is modified.

As a result, users benefit from the Theorem technology without needing to undertake a separate translation operation and without having to worry if any changes have been made to the imported parts.

UGNX, I-DEAS and Pro/Engineer data will be the first non CATIA V5 formats to be made available within the CATIA V5 MultiCAD environment using CADverter technology and demonstrated by Theorem for the first time at the European CATIA Forum (ECF) in Paris during November.

Commenting on the new development, Keith Jeacock, Theorem’s general manager said: ‘We are delighted to be capitalising on our close working relationship with Dassault to bring our leading edge translation capabilities to the X-CAD platform.

This new and exciting application of our technology provides CATIA V5 users with a very powerful way of collaborative working within a MultiCAD environment.’ * About Theorem Solutions - Theorem Solutions is recognised as one of the world’s leaders in CAD/CAM product data exchange, offering application programs for Direct Database conversion and for International Standards-based conversion methods (STEP).

The Theorem CADverter family is the widest range of direct CAD translators available from any single source.

It includes CADviewer, data exchange Navigator (DXN) and CADhealer, all delivering improved communications and interoperability between CAD systems.

http://www.manufacturingtalk.com/news/teo/teo130.html

available from OneCNC are XR Lathe Express and Professional for C NC turning, and XR Profile Express and Professional for CNC lasers, plasmas, waterjets, oxy torches and CNC routers, which include new technology for nesting and sheet optimization.

According to the company, key features are improved functionality, user-friendly menus and the capability to machine 3D parts quickly. The company also says that the XR series for milling, turning, profiling, wire EDM and design provides users with a means by which to reduce programming time, increase part quality and expedite delivery.
The XR Profiler has been developed for CNC profiling, and it provides users with the tools to design, import, program and post process NC programs that connect with virtually any CNC laser, waterjet, plasma, oxy torch and CNC router.

Other features of the series include solid machining technology, rapid implementation, a NC manager and functions for creating, managing and editing CAM operations. Additionally, users can customize postprocessors using natural language.

http://cnc-info.blogspot.com/

Manufacturing software has come a long way in just the last five years. Independent software developers point out some of the advancements in manufacturing software in the hopes that some fabricators realize they may be missing out on some real production-optimization tools.
Looking for software to run its 13 laser cutting systems spread across two job shops, Laser 3D, based in Melbourne, Australia, chose Camtek’s PEPS five-axis CAM software to run its LaserLab and TRUMPF lasers. The software helped to reduce setup times by 50 percent, because operators no longer had to conduct manual teaching of the laser cutting heads, and fixturing times by 80 percent.

Software has changed the nature of fabricating. Most fabricating shops hammer out the manufacturing details of a job on their own computer-aided manufacturing (CAM) software packages immediately upon receipt of the customer’s engineering drawings. Some of the more aggressive fabricating shops even might go back to the engineers and suggest ways to make the part more manufacturing-friendly and, perhaps, take some cost out of it simultaneously.

Some fabricating shops are going a step further—engineering parts and assemblies for customers. The computer-aided design (CAD) tools that used to be found only on the desks of engineers working for Fortune 1000 manufacturers are now available for those further down the supply chain, including fabricators.

In short, CAD/CAM tools have grown more affordable and user-friendly, while manufacturing relationships have grown more complex. Fortunately, the software tools, particularly from a CAM and nesting standpoint, are helping fabricators to stay competitive with the hope of improving even more.

Glenn Binder, vice president of sales, SigmaTEK Systems, said the folks at machine tool builder Mazak understand the opportunity that lies ahead for fabricating shops.

“Mazak calls it the 93 percent/7 percent rule,” he said. “They say we spend only 7 percent of our total manufacturing lead-time burning. Ninety-three percent of the manufacturing lead-time—defined as the time between the customer placing the order to the time that the fabricator delivers the goods—is time wasted on non-value-added activities.”

That leaves a lot of room for improvement, and software can play a large role in whittling away that 93 percent. To get a better idea of just what manufacturing software can do, The FABRICATOR talked to several independent software developers to determine just what a fabricator’s software package should be capable of so that it can stay ahead of the competitor down the street and around the globe. The following are some questions that need to be asked.

Just how flexible is your current manufacturing software?

From the most basic perspective, manufacturing software tools just aren’t built the way they once were. The software is built in a 32-bit environment, not on the reliable but not-so-flexible DOS platform, and the database technology associated with the CAM software allows for easy information exchange between the software and the machine tool controls.

“Now it’s a much more open environment,” said Luca Poggi, sales manager for Computes Inc. “The customer can customize the software himself. For example, he can import information in Excel, ASCII, or other files from one system to another.”

That sort of flexibility is necessary for a majority of fabricators because they want to maintain some sort of control over the manufacturing process. They are not ready to surrender complete control to software.

SigmaTEK’s Binder said he believes 80 percent of his company’s software
COPRA® MetalBender from data M Corp. is an example of software that can integrate with other software. It interfaces with systems such as Cybelec, Delem, and ToPs and is available for CAD packages such as Autodesk® Inventor™, Mechanical Desktop®, and AutoCAD®. users are working in a manual or semimanual mode when it comes to preparing sheet to be cut on the shop floor. Some are nervous about the technology supplanting someone’s contribution.

“The folks also are nervous that these software tools are going to replace jobs, which in our experience doesn’t happen very often,” Binder said. “These are very good folks and skillful folks that can work with these tools. They either oversee the automation or move up in the organization.”

Others need to be able to lay out nests manually because of certain details on the shop floor. For example, a steel service center may need to ensure that small parts are not nested in certain areas of the sheet because when they are plasma-cut, they might fall into the sump of the plasma cutting machine, becoming irretrievable unless the machine is shut down.

Manufacturing software’s flexibility to work in a manual mode is important for some, but its ability to automate manual tasks is where software can make a big difference. The nesting algorithms that are available today simply weren’t available only a few years ago because of underpowered computers.

“We literally had ideas for algorithms five years ago that we couldn’t use because it would have taken you six hours to do a nest,” said Oliver Goettsche, national sales manager, MTC Software Inc.

Derek Watson, MTC Software’s international sales manager, offered up the advances in common-line cutting as an example of what the new nesting algorithms are capable of. Common-line cutting—in which the cutting device cuts a line between two straight-edged sheet parts leaving no space between them—used to be limited to common lines shared by rectangles and squares in an array. Now any combination of shapes that have at least one straight edge on the part can be nested for common-line cutting.

Automatic nesting is just one way that manufacturing software can save fabricators time. More software packages are equipped with bending, cutting, and forming simulation, which helps to streamline the actual fabricating process. Albert Sedlmaier, managing director of data M Corp., said such developments put the software closer to computer-aided engineering systems than typical manufacturing software.

Doug Wood, the Radan team leader for Planit Solutions Inc., said he has heard from fabricator customers that have saved at least 45 minutes in setup time by using the bending simulation features of the Radan CAD/CAM software. In addition, the simulation helps to eliminate the trial-and-error process that comes with running a first-time press brake job.

“It’s a whole lot cheaper to scrap out those three or four parts electronically and offline,” Wood said.

Is your manufacturing software compatible with the 3-D world?

Over recent years the prices for solid modeling systems, such as Autodesk® Inventor™, SolidWorks®, and UGS’s SolidEdge, have fallen to the point where it is no longer cost-prohibitive for small and medium job shops to invest in a software license or two. The world of 3-D design has come to the masses.

With the newfound design muscle, fabricators had to ensure that their manufacturing software could function in this 3-D world. Fortunately, many software developers have come a long way in ensuring that 3-D drawings lead to automatic tool selection and nesting layout, just as the software did for 2-D drawings. And when changes need to be made to the 3-D drawings, it’s not that big of a deal.

“It’s minimal,” Wood said. “Traditionally, customers in the past sent flat DXF files back and forth. When whoever was forming the components needed to modify the part, in some cases they basically had to recalculate the flat pattern to get the part to match the press brake tooling and get the desired outcome.

“By working with 3-D data, it’s much simpler to manipulate the geometry, make a minor change to it, and get the part correct.”

Ed Patterson, vice president of technology, Vero International Inc., said this type of change on-the-fly is possible because software is no longer constricted by a history tree, a record and collection of every change that is made to a design drawing over the drawing’s history and up to the most recent modification. When a change is made to a 3-D model, a designer doesn’t have to worry how this might affect an earlier revision.

Patterson said Vero’s die design software allows users to cut out a piece of a die, replace it with a new piece, and carry on with the project.

“We are seeing people enjoying their work because they can do a representation of what they are going to get, three-dimensionally,” Patterson added.

How is your manufacturing software prepared to deal with data management?

Working with 3-D drawings and translating them into useful manufacturing files can be a wonderful thing, but it also opens the door to some new concerns.

“The shortcoming with these modeling systems is that once you talk about doing everything as a 3-D model versus individual drawing files, there is a lot more data that has to be managed,” said Michael Boggs, sales manager, Striker Systems.

The result is the creation of a software product called a production data management (PDM) solution. The PDM product consistently would verify that the latest revision is being worked on. The software also would control who could check out design drawings and keep track of drawings checked back in. It would act as a sort of master revision control system.

Boggs said that PDM products targeted to the fabricating world are relatively new, and most CAD/CAM products in the fabricating shops don’t have programming interfaces that allow them to interact with the new data management tools.

In lieu of a PDM solution, Boggs said an alternative might exist. For every job revision a customer releases electronically, the fabricator can request that a revision number be designated to the order. If the revision number does not exist in the fabricator’s part library, the manufacturing software automatically could flag the customer to let him know that the fabricator doesn’t yet have this revision or a new number needs to be issued.

At the very least, fabricators probably need manufacturing software with some sort of shared library system offering to keep up with the trend toward more 3-D data, according to Boggs.

Can your manufacturing software connect to the latest front-office software products?

The days of having a traveler card for a specific job order be the main source of manufacturing information in a fabricating operation are nearly gone.

First came the emergence of material requirements planning (MRP) software that used bills of material, inventory data, and production schedules to calculate material requirements. The software could recommend the initiation of new orders for materials as inventories dwindled and even reschedule jobs when due dates and shop floor realities did not align.

Enterprise resources planning (ERP) does what MRP software did, but reaches over the entire business. ERP handles not just inventory and resource tracking, but also covers all aspects of financial, manufacturing, and distribution management. Many view this type of software as the neurological lifeline for decision-makers because it provides the needed information to make informed business decisions.

“We are getting a lot of interest in this area,” said Planit Solutions’ Wood. “The need to have the production data and the schedules interfaced with the CAM software is necessary to prioritize jobs.

“With this ability to pull this data from the MRP system, you can drive the manufacturing software, the nesting, and other components with the information and on the back side get reports of what was produced and where jobs are at.”

This trend has led many manufacturing software companies to develop interfaces with some of the leading MRP and ERP software used in the manufacturing space. Some manufacturing software developers even have created custom interfaces to work with homegrown front-office systems that might have sprung from the mind of a talented database administrator.

In reality, most have basic MRP systems or job shop management systems that handle the creation of job orders, production schedules, and quoting. Whatever the case, the need to have an up-to-date picture of the manufacturing operations leads to more efficient operations.

MTC Software’s Watson said this level of connectivity between manufacturing software and front-office software automates formerly paper-based processes, helping to remove cost and possible mistakes from the production process. At the very least, he added, people are looking to have the bill of materials accompany the manufacturing drawing.

That level of connectivity is going to become more important as larger manufacturing customers rely on the Internet to communicate with their contract manufacturers. Job shops that rely on older manufacturing software or that fail to ponder future information technology may find themselves working on retirement plans instead of manufacturing drawings.

http://www.thefabricator.com/CADCAM/CADCAM_Article.cfm?ID=1513

For many years building drawings were painstakingly created by hand using pen and paper on a drafting table. Any changes often required new drawings to be created or at the very least sections redrawn. The advent of the desktop computer soon gave rise to Computer Aided Design (CAD) drafting allowing drawings to be created on a PC and printed electronically. Changes could be made quickly without having to redraw the whole drawing.

With over 1 billion paper and linen drawings in map cabinets throughout North America and probably that many drawings lost or destroyed, there is a booming service industry to create computerized CAD drawings of existing buildings.

Many people wishing to create drawings of their facility have asked themselves questions like these:

* How can I accurately create drawings of my buildings using old paper drawings?
* How can I use the memories of the maintenance personnel who have worked in these buildings for years so their knowledge is in my drawings?
* How do I use the drawings from recent renovations and additions that are already created electronically?

Depending on the quality of the existing drawings, the changes over time to the building and whether drawings are even available the creation of CAD drawings of existing buildings falls under two categories. The first category involves taking an existing drawing and manually or electronically creating a CAD file. The second category involves measurement of an existing building to create a CAD file. The latter is done when drawings do not exist or many changes have occurred over time making the original drawings obsolete.

Different names are used to describe existing and newly created drawings.

* “Design” drawings are used for project proposals to clients.
* “Working” drawings are used to secure building permits and are given to contractors for construction.
* “As Built” drawings begin with the “Working” drawings and include changes made during construction.

“As Is” or “Existing” drawings refer to the measurement of existing buildings to create accurate CAD drawings of the facility. This process is done after construction, before a renovation, when no drawings exist or when accurate CAD drawings are required for use in a Facility Management program. This type of drawing reflects the building as it is today.

The following techniques for creating CAD drawings of existing buildings are in use today.

Paper Takeoffs
Individual lines are measured on a drawing using a ruler then entered into a CAD program. This is a time consuming and inaccurate method. The ability to measure and record room names and fixture locations accurately is hampered by the ruler divisions and paper quality. Given the other options available this technique is not recommended.

Scanning
Scanning involves feeding a paper drawing into a scanner to create a digital image in pixels. The image produced is commonly referred to as raster format, similar to what you see if you magnify a newspaper image, a bunch of dots. Fax machines are small-scale scanners the difference being that the fax machine reads a page, converts it to a digital image and sends the image to another fax machine, which turns it back into a readable document. Raster file formats available include TIFF, PCX, CALS and RLC. The consideration here is to save the scanned image to a vector format recognized by the raster to vector software.

If you think scanning is the way to go about creating drawings of your facility consider these points first:

* are you doing this to archive and view your existing drawings before they disintegrate?
* are your drawings in good shape?
* are they clear?
* has the building changed since the original drawings were created?
* is there a clear cost benefit?
* will the files be converted to vector format later on?
* will conversion to vector format give you what you want?
* does it make sense to scan all of your drawings?
* do you want the digital image to be exactly the same as the paper image?
* do you want to use these drawings in a facility management program?
* are you concerned about accuracy?
* will other methods of creating CAD drawings better meet your needs?

The primary use of a raster file is to have a copy of an original (archive) for retrieval and inspection. This process requires either a CAD program that can view and edit raster files or a separate viewer. Very few of the CAD programs on the market today support the manipulation of the raster format files beyond viewing. This means that the raster files need to be converted to vector format.

Manipulation and viewing of scanned files can be done using simple paint programs already loaded on most PC’s. Editing and cleaning up these files will make them smaller and more manageable for storing and vectoring. More elaborate editing programs will; deskew which straightens the image; despeckle which removes dots below a certain size and remove, copy or erase parts of the file. The cleaner the drawing is the better it will convert to vector format.

Vector Conversion
Raster files are often converted to vector format. Vector entities are described by coordinates and equations such as start and end points for lines and centers and radii for circles.

Different techniques are used to vector a raster file.

Manual or heads up conversion requires an operator to manually digitize by tracing over the existing dots, which creates individual vectors. This is a time consuming process requiring many judgment calls by the operator.

Interactive conversion uses software to create the vector file. The operator defines the parameters of the software and any interpretations are asked of the operator not assumed by the software. The advantage of software in this case is that an operator bases calculations and estimates on mathematical calculations by the software instead of interpretation.

Automatic conversion involves the use of conversion software to automatically convert the raster image into a vector file without the assistance of an operator.

Except for heads up conversion, more time is required to check accuracy of the converted file based on the original drawings. Quality Checking (QC) the drawing to the existing building and the insertion of new CAD drawings may be required to update the file to more closely represent the building as it is today.

In scanning and vectoring methods interpretive errors are often made. To avoid any misunderstandings clearly define what you plan to use the final product for before your drawings are converted.

Digitizing
Digitizing is another method of converting existing paper drawings to CAD. With E Size digitizing tablets now available on the market, a typical architectural drawing can be converted to CAD in a very short period of time. The difficulty with “copying” an existing drawing lies in the accuracy of the data being entered.

Ask yourself these questions:
• how will changes to the data be updated?
• how accurate is the original drawing?
• how much will it cost to QC the final drawing?
• how accurate will the final drawing be?
Sometimes all changes to original drawings were not accurately or systematically recorded in a manner that reflects the building as it is today. If changes were contracted to an outside architect or designer it may be too costly to secure copies for your records unless originally tendered. To avoid this expense be sure to include in your project tenders a request for CAD copies of the drawings for your records.

Getting and organizing original drawings for scanning and vectoring can be a daunting task. Sometimes drawings were poorly stored, lost, stolen or permanently borrowed and when you try to get copies you find that companies no longer exist or they don’t have the originals.

In some cases scanning, vectoring or digitizing may not be the most accurate or cost effective means of creating CAD drawings. The way to accurately create “As Is” drawings is to use one of the following measurement techniques.

Team Site Building Measurement
The team measurement technique involves sending 2-3 people to a building with a sketchpad and has them physically measure each room and area of a building. The measurements are transposed to a sketch.

The sketch is then recreated at a CAD station to produce a CAD file. The CAD work requires some preliminary parameters to be set up by the operator. The parameters may include layering, symbol type, insertion and rotation, area calculations and dimensioning. These parameters are usually agreed upon with the client before any work begins.

If all the measurements are accurately recorded, legible and complete no fudging or return visits to the site will be required.

The problem with this technique is the possibility of errors. Missed site details and reversed measurements during the dictation, recording or CAD work may occur.

When the client wishes to have additional elements defined in the drawing such as plumbing fixtures, life safety fixtures and furnishings this technique is not very practical. The measurement team may require several passes on site causing unnecessary disruptions or the CAD time required to create the drawing becomes too costly.

Electronic Site Building Measurement
Electronic Site Measurement is done using hand held or laptop computers, data collection software and a steel tape measure. Sometimes electronic laser devices are also used. This technique creates “As Is” CAD drawings.

The principles are the same as team measurement. The primary differences are in how the data is collected, what data can be collected and how many people are used to measure the building. Using a hand held computer one person can physically measure 10,000 - 30,000 square feet of space a day. One person using a laptop will reduce measurement speed. Two people and a laptop will be quite fast but labor rates will increase. Using software on a laptop for occasional small jobs may suffice.

Measurement begins from a predetermined start point and the survey proceeds from one room/area to another until the complete area is entered into the software.

Accuracy checking is built into the software so that every room/area is checked before leaving the site. Symbols such as plumbing fixtures, electrical outlets, furnishings, text entries and wall types are entered on the fly as the survey is conducted. Surveying in this manner also eliminates multiple visits. Every line entered can be modified and additional information inserted before leaving the site thus ensuring an even greater degree of accuracy and detail.

Once the survey is completed the data is converted to a Drawing Interchange Format (DXF) file used by many existing CAD programs. The DXF file is then imported into a CAD program and a multi-layered drawing is created containing all the symbols, text, walls, doors and windows as they were input into the software on site.

Using software is a fast and accurate means of updating existing drawings in the field.

Choose the technique that best suits your everyday and long-term needs. Do not be bullied into accepting one technique only to realize that down the road spending a few extra dollars would have saved a lot of headaches and money.

The goal of this paper was to shed some light on the different techniques used to create CAD drawings of existing buildings and provide everyone with enough knowledge that they are able to make an informed choice when creating drawings of their facilities.

http://www.facilitymanagement.com/articles/CADindex.html

only thing that will never change is change itself. This has never been so true than in manufacturing industry. The technology of manufacture has become so advanced that process’s that used to take weeks can now be done in hours, and components that used to need 2, 3 or sometimes more machine tools to complete them are now fully machined from start to finish on a single machine with only one setup required.

What’s more the machine tools have become steadily more affordable as more companies realise their usefulness and how easily they reduce manufacturing costs and directly affect the bottom line. This has led to larger volume and in turn cheaper prices.

5-axis machining centres are a good example. Only 10 years ago there were probably only a handful in the country and their price tag was in the millions, but now almost all large toolrooms and many small to medium sized companies have at least one and they can be bought for a fraction of their original cost.

But all of these machine tools are CNC, they have to be in order to do achieve what they do, but what about cad/cam software? Is it keeping up? Can you still use the same software from 10 or even 5 years ago to run these machines?

We the answer is of course no, you cannot. In many cases it has highlighted the outdated nature of some software’s core processing methods; do not forget that many of these products have been around mostly unchanged in their core structure for 25 years or more. Modern machine tools such as the ones mentioned are capable of working on multiple sides of a component without resetting and controlling as many as 14 or 15 axis and up to 6 of them simultaneously. Obviously when development of these products began this kind of capability was never envisaged.

To be able to work with confidence with these machines, modern software must allow the user to model the machines themselves and the workholding fixtures accurately and then to faithfully replicate axis movements exactly as they will occur on the shop floor.

The new software takes the form of a single totally integrated 3D CAD and CAM system, which allows the user to not only model complex components in either solids, surfaces or both but also to machine the parts on any form of machine tool no matter how complex it may be.

The CAD capabilities are totally mainstream and are not limited to single components; CAD capabilities can model assemblies, do mechanical simulations and is fully parametric. CAD capabilities have optional extensions, which encompass mould design, stamping/progression tool design and even sheetmetal design.

Without leaving the CAD environment the user can then place the part onto a machine tool (either in a vice, chuck or on a fixture) and begin machining in a complete simulated environment with full collision checking. The user works directly on the 3D model itself and of course, if the model needs to change then the toolpaths will update themselves.

True integration is the only way forward

Obviously a completely integrated package from one developer means that the part, the tool, the drawings and the machining are all linked, all of the time, so changes and improvements are handled with ease. And of course, you only need to learn how to use one package not 2 or 3 separate ones.

To fully understand the benefits of a complete one-package solution we need to see what happens when we explore the alternative, that is to use a number of separate packages from different developers and trying to get them to work so called seamlessly together.

Interfacing

Whenever 2 or more software packages need to communicate there is always room for error. Sometimes it may be a minor problem but often the problem will be more severe. Each software supplier writes their own code to handle complex geometry. If there are any differences in the way one or the other describes a lofted surface for example, it means you will not get exactly the same shape as was intended. With an integrated product with both CAD and CAM there is absolutely no possibility of transfer errors.

Data loss

In TopSolid for example you may add numerous forms of additional information onto your part models. This can include tolerances, surface finish requirements, machining methods etc. All of this information can be automatically read by TopSolid CAM, of course when transferring model data between 2 separate products this information is lost.

Version lag

This is a very common problem and it happens when one of your software suppliers releases a new version of its software, of course this means that your other package is now incompatible and will no longer work! You cannot afford to lose half of your capability so you simply have to put the new version back on the shelf until the second supplier catches up.

Fragmented support

As long as you have 2 or more suppliers then each of them are free to play the blame game when something goes wrong. Is it the cad’s fault or the cam’s fault? Another aspect of this problem is what happens when you find a bug in the software. If it’s a bug that impacts both packages, you have twice the workload in reporting and monitoring the result. Also if one supplier does indeed isolate a problem in the others software, they cannot fix it they can only report it while you wait and wait.

Future direction – no control

As each software company develops it products, they do so to suite their own goals and requirements. Ultimately this could affect the level of compatibility with other systems.

Why do we need CAD and CAM together?

Realistically these days when we talk about CAD, we are actually talking about 3D models not 2D drawings, and many stand-alone CAM products on the market are simply not capable of mainstream design and modeling. At best they produce acceptable 2D drawings and simple model geometry for machining purposes but that’s all. A full featured mainstream 3D modeler can work in both solids and surfaces, work with single parts and assemblies and automatically produce associated 2D drawings and many of them offer advanced capabilities such as mechanical simulation, analysis etc.

The real benefit of having these capabilities alongside your CAM system is that it gives you the user, complete control over the whole process. You can work from paper drawings or from 3D models but of course we all know that manufacturing is all about changes and with a completely integrated solution you can adapt to changes easily and the toolpaths will automatically adapt themselves.

Another major benefit highlighted by some of the customers is the ability to design work holding fixtures on the fly. Once they have specifies what the raw material will look like they then use the CAD system to model any special jigs etc that are required. TopSolid comes complete with a fully configured library of 3D parts including cap screws, nuts bolts etc and as the user does not have to switch from CAD to CAM he is free to design any time he needs to.

In 5-axis work it is essential to have every aspect of the machine tool and work holding environment accurately modeled if you are to avoid collisions and in a true 3D modeller, this is a relatively simple process and once again as the user is in a single integrated environment these items are visible at all times and the system can warn the user of any impending problems.

Also bear in mind that having a single integrated CAD and CAM system also means you ever have to say No. Whatever your customer asks you to do, you can do it.

In many cases, the users have gone ahead and bought separate programs simply because they did not know that products like the TopSolid range were available, and in a number of cases they have avoided the evaluation process by simply going the same route as a colleague or supplier. Another major misconception is that integrated software is enormously expensive and out of their price range, this is simply not the case as our integrated package is priced on a par with almost all the stand-alone CAD and CAM products currently on the market and therefore provides exceptional value for money.

Specialist products for specialist tasks

There will always be a need for dedicated stand-alone products as many companies would have already made their choice for a particular CAD system for instance and are happy with it. Alternatively we have clients whose business is purely machining and do no design whatsoever. In either case they look for a CAM package that offers the most suitable features for the type of work they do. Contrary to popular belief all CAM packages are not equal and the quality of your work will be directly affected by poorly calculated toolpaths or even worse a gouged component.

Another good example would be dedicated toolrooms who concentrate solely on the 3D machining of complex mould tools. In almost all cases the geometry of these tools will be provided by the client and so in this case we need a software package which can accept CAD data in almost any form, especially in a native form i.e. without using a 3rd party translator like IGES or STEP etc. This greatly reduces the risks of corrupt or misrepresented geometry.

A product such as WorkNC for example can apply roughing and finishing toolpaths onto a model regardless of its complexity or physical size in an almost totally automatic way. The user simply tells the software which tools to use and which toolpaths to apply and the software does the rest. In many cases users of a system like this gain such high levels of confidence that they are happy to allow their machines to run unattended overnight or over weekends.

What to look for, what are the essentials

The evolution of the machine tool industry into combination machines and the increasing affordability of 5-axis has been discussed, so it is important to try to look ahead when making an investment in software. So when we hear people say we do not do that so we do not need that feature only to realize that once you have such a powerful tool in your workshop you can widen your capabilities.

Versatility should be your number one consideration when evaluating Cad/Cam software. In the same way that machine tool prices have been steadily dropping then so has the software. It simply does not make sense to invest in a product that will only cover you for your present day requirements when for the same money you can buy a package with capabilities extending far into the future no matter what the machine tool industry comes up with, and whatever your clients ask you to do.

Constant 3D stock monitoring is essential if you want to minimize air cutting. Software like our always knows exactly what the stock looks like and so makes intelligent decisions when roughing and finishing ensuring that it only cuts where its needed.

Modern software should have the ability to learn from you, in other words, retain knowledge for re-use. Especially if your business tends to do work of a similar nature but from a number of different clients. It is a huge time and cost saver if you can store away a pre-determined set of machining processes and simply re-apply them to a new component. Even if there are a number of small modifications to be made it’s still a lot quicker than starting over each time.

Feature recognition is a major time saver when programming. This is the ability to recognise features such as drilled, reamed and tapped holes, pockets, faces and bosses etc and to know exactly how you want to machine them and what tools to use etc. and make sure that any product under consideration can recognise these features on imported parts as well as native ones.

Look for a true CAD capability, not just simple part modeling. Make sure you get complete solids and surface capability with assemblies and mechanical simulation. Automatic 2D drawing production is 100% associative and a huge timesaver.

Accurate machine tool simulation ensures the user always has a complete picture of the entire process including vices, fixtures and clamps etc, but in many cases these extra graphics can slow the software down dramatically. Make sure that you can work in a fully simulated environment without a performance penalty.

5-axis machining has many benefits, one of which is the ability to reduce or eliminate the use of long tools. A major feature to look out for is the capability to automatically convert 3-axis toolpaths into 5-axis toolpaths. This makes the whole process of working in 5-axis extremely simple because the software will calculate how far over it can tilt the spindle without causing a collision. Using this technology we have clients reporting a reduction from a required tool length of 105mm being reduced to 35mm. If you currently do not have 5-axis machines then look for the ability to automatically split a tool path dependent on tool length. This will allow you to use more suitable machining methods for the longer tools.

Finally consider the quality of the support you can expect after the sale. Sad to say that in far too many cases CAM support is done by CAD specialists most of whom have never set foot on a shop floor let alone operated or programmed any form of CNC machine tool.

http://www.ferret.com.au/articles/z1/view.asp?id=17092

CD-adapco’s ‘Best Practice Guidelines on CAD for Simulation’ directs users on how to use CAD to optimise their flow and thermal simulation. This initiative is consistent with CD-adapco’s goal of transferring their industry leading CAE know-how and expertise to its partners.The CAD or PLM tool is at the backbone of product design process, and with the Star-CAD Series, can be utilised to quantify and optimise a design’s flow and thermal performance.

By making best use of the CAD tool’s functionality, significant improvements in simulation time can be achieved, allowing designers to run more ‘what-if’ studies and further improve product performance.

Star-CAD Series Product Manager, Jean-Claude Ercolanelli, recognises the importance of these documents.

‘A few simple guidelines on how best to use the CAD tool to focus the simulation on important features can make a significant impact on model turnaround time and productivity’.

He also recognises their synergy with features in the latest release of the Star-CAD, ‘In combination with the new automatic model checker in STAR-CAD Series V4.10, CD-adapco now offers the most robust CAD-embedded process on the market’.

‘The Best Practice Guidelines use the STAR-CAD Series to demonstrate hints and tips, but they are equally applicable to any simulation process.

The guides are available for all four major CAD packages - SolidWorks, Catia V5, Pro/Engineer and Unigraphics NX - and are freely available from the company’s website.

http://www.engineeringtalk.com/news/cdp/cdp148.html

you’ve just wrapped up your part design and you’ve certainly earned a break. But don’t shut down your computer just yet. You may not be through.

Depending on which computer-aided design system you use, you might need to translate your design data into an open format like STEP or IGES before sending it on to the computer-aided manufacturing system. There’s a good chance that your company’s CAM system might not speak your CAD system’s native language. Even when CAD and CAM are compatible and you get to skip this step, you’re likely to get some questions from the manufacturing floor as engineers there determine how to best transfer information from CAM to the machine tools that will manufacture the part.

There’s even a possibility that you’ve designed your part in such a way that it can’t actually be manufactured—or, at least, manufactured easily or at low cost. Your CAD system hadn’t alerted you to that, had it?

These are some of the issues in CAD and CAM compatibility today, according to Satyandra Gupta, a mechanical engineering professor at the University of Maryland in College Park. Gupta’s university profile lists his research interests as “geometric reasoning algorithms for computer aided manufacturing; integrated product/process design decision models.”
CAD and CAM can often communicate back and forth only in an open format. Then CAD info must be interpreted by the manufacturing engineers who move information from CAM to the numerically controlled machines. Interpreting CAM information in order to program those tools requires a human operator who has to know quite a bit about machining in order to select the best cutters, tools, machining processes, and tool paths, Gupta said.

Streamlining CAD and CAM handoff has long been the dream of engineering organizations that face handoff issues every day, he added. Many manufacturers would love to put an end to the cumbersome interpretation process.

“But you just can’t get the human out of the loop,” Gupta said.

“What designers ideally want to get to is a system where, after finishing a design, they could press a button on the computer and fabrication could automatically begin,” Gupta said. “The idea is: They should be able to go from CAD to CAM with all the decisions about starting production made automatically.”
In other words, press a button on your CAD system, wait a bit, walk down to the manufacturing floor, and get your part. CAM handoff is automatic and CAM’s codes can be fed automatically to numerically controlled machines in the manner most appropriate to create the prescribed part.

In his Maryland lab, Gupta and his team work out algorithms that would power CAD software toward such an end. Leaders of at least one company, meanwhile, say they’re already there, but they had to write the software on their own.

Cut Out the Middle

The company, Protomold Co. Inc., ties CAD directly with CAM, to do away with requiring a human in the loop. It makes plastic injection-molded parts from customers’ CAD models. Protomold, just west of Minneapolis in Maple Plain, Minn., boasts that it can immediately offer a manufacturing quote based on a CAD model submitted via its Web site, and deliver parts to your door within three days.

“That was unheard of even three years ago,” Gupta said.
How can Protomold quote so quickly and deliver so fast? By doing away with the middleman—in this case, the manufacturing engineer in front of the CAM software.

The Protomold story began in the middle 1990s with Larry Lukis, the founder of LaserMaster, which made computer printers and desktop publishing systems.

“He discovered he could get printed circuit board prototypes made overnight, but that little plastic parts would take a month or two to make and cost $20,000 because of the time and the hassle to make the plastics mold,” said Brad Cleveland, Protomold’s chief executive officer.

To make a plastic part, you must first make a part mold and then essentially press the plastic into the mold, eventually breaking it open to reveal the completed part. Molds can be as complicated or simple as the part they’ll eventually create, but they’re very often expensive to make, Cleveland said.

Lukis, who fostered a love of software programming, knew what to do. According to Protomold, Lukis and more than a dozen colleagues went to work writing software that would smooth the hassle and allow for the automatic programming of manufacturing machines from a CAD file.

Lukis founded Protomold eight years ago. Customers load their CAD parts on the company’s Web site and the site quickly returns a quote. No human is involved even in that process. Lukis’s software generates quotes automatically. If the part can’t be easily manufactured, the software gives feedback on how to best change the CAD model for manufacture—again without anyone overseeing the feedback process.

The Protomold software, all of which Lukis wrote, runs on parallel processors—several computer clusters, themselves comprising dozens of linked computers.

When a customer orders a part, the company’s software designs the mold automatically based on the CAD file and also automatically generates the commands—the tool paths—for the milling machines that will create the mold components. Protomold runs dozens of milling machines that make components of aluminum. Employees assemble the components into the actual molds in a factory next door, where parts are molded.

“We can do this in a few days largely because of the software that automates most of the process.” Cleveland said.

Protomold employees monitor the process to ensure that it runs smoothly, he said. The company designs dozens of molds per day, he added. The software can now make much more complex molds than when Lukis first fired it up.

“There’ll always be limitations, typically on size and complexity,” Cleveland said. “If it’s too big, we tell that to the customer. If it’s too complex, we might recommend they change little areas. So we give them back helpful advice.”

In fact, a handful of engineering professors have begun to ask students to submit their designs to the company’s site for a practical critique of manufacturability, Cleveland said. Feedback like that is vital to fledgling engineers, Gupta added.

Easy Overrides

So why can’t more companies follow the Protomold example? Perhaps because Lukis wrote his software exactly for one company’s needs—Protomold’s.

In addition to being too expensive for vendors to sell, the automatic CAD-CAM handoff research now in the pipeline at Gupta’s university might be too generic for the many manufacturers that tune their manufacturing lines to their own needs and appreciate CAM software that can keep up. The advanced CAM software would automatically generate tool paths using settings that might not work as standard at every engineering company. Many companies customize their CAM software to accommodate special glitches in their manufacturing equipment, Gupta said.

“Right now, we’re working on generic software where you can press a button and it spits out an answer for a generic machine.” he said. “But you might not do things that generic way.
Let’s say your software says you need to clamp this part in a vise, but you don’t have a vise mounted. You want to use a tool clamp,” Gupta said. “You have to manually override that. Or let’s say you’re getting a CAM system, but you’re going to set milling speeds higher than it specifies.”

Again, a manual override is in order.

Often companies will call in CAM consultants to customize software, or they’ll try to do it themselves, although the customization is often over the heads of all but the most advanced software users. This, of course, takes time and money.

“Right now, it’s unbelievably expensive to customize those things,” Gupta said.

CAM systems of the future should include easy workarounds that any company could use to customize the software. And Gupta hopes to eventually have a hand with development.

Gupta estimates that his algorithms will be worked out in five to six years. CAD vendors will then be able to incorporate them in their software, he said. The software in this scenario would alert engineers to potential manufacturing problems that a part faces. An alert would give engineers the option to redesign for easier manufacturability. This type of feedback would resemble the analysis-on-the-fly information now returned to engineers via desktop analysis software, Gupta said.

“CAD systems today do include some manufacturing expertise, like they tell you a section thickness is too large. They can point out obvious problems,” Gupta said. “But as problems get more subtle, you don’t get good manufacturability feedback.”

Still in the Loop

Like other computer-aided engineering applications, manufacturing software is being pushed forward, although innovation and research is mainly the purview of academics like Gupta. Whether CAD and CAM vendors can make a business case for implementing them remains to be seen, as closely linking CAD and CAM could make software more expensive, Gupta said. If it can be commercialized, a streamlined CAD and CAM handoff in the mechanical engineering realm might one day come to mirror some of the technologies already available today.

For example, take laser cutting, an industrial manufacturing method that uses a laser to shape and cut materials, like carbon steel or stainless. Laser cutters take input directly from a CAD drawing to produce forms of great complexity. Although the laser cutters mainly slice through flat sheet material as well as through structural and piping materials, some types of lasers cut parts that have been preformed by casting or machining methods, Gupta said.

For a technique that marries CAD and CAM closer to home, consider rapid prototyping. When it first came on the scene some 20 years ago, the ability to print a digital design in three dimensions seemed like a technology straight from the pages of science fiction. The shape stored in your computer assembled itself from a claylike material right before your eyes. You could hold that design in your hand—often that same day.

Rapid prototyping as it stands today reflects where researchers like Gupta hope to see the CAM industry eventually evolve for mechanical engineers. To make a rapid prototype of your CAD part, you press a button and the system loads instructions into the rapid prototyping machine that automatically begins building the part one layer at a time. Three-dimensional printing, a form of rapid prototyping on a smaller scale using more compact technology, allows you to print single parts within moments. And you barely have to leave your desk. The printer can sit nearby.

Two decades after the introduction of rapid prototyping, some manufacturers now turn to the technology to make production-quality parts in small numbers. Because pieces are still made in small batches and production per piece can be relatively expensive, the process doesn’t support large-scale production. It’s still cheaper for manufacturers to use injection molding to make plastic parts, for instance, and thus Gupta continues to work in the CAD-CAM field.

So, while there’s been talk “almost forever” about getting the human out of the CAD-CAM loop, Gupta said, it looks like the scenario might no longer be that far-fetched.

http://www.memagazine.org/contents/current/features/camstand/camstand.html