Blurring the Lines Between CAD and CAM
With more integrated CAM, cloud-based options, better simulation and multitasking tools, users gain more choices in CAD/CAM programming
By Patrick Waurzyniak
In the manufacturing world, users of CAD and CAM software constantly seek out the fastest, most efficient ways of programming machine tools that cut, bend and shape metals and other materials into finished components. With today’s more integrated desktop CAM software that run within solid modeling applications such as Dassault SolidWorks, Siemens Solid Edge or Autodesk Inventor, users get more affordable, easy-to-use systems that have been gaining traction in recent years as designers seek tighter links between design and manufacturing.
When CAD giant Autodesk Inc. (San Rafael, CA) moved last November to buy CAM-centric software developer Delcam plc (Birmingham, UK) for $286 million, it was one of the larger CAM industry acquisitions in recent memory, signaling the potential for big changes in the highly fragmented CAM market. Autodesk, creator of the ubiquitous AutoCAD and a $2.3-billion business, has acquired a host of software technology in the past year or more, mostly in design and simulation, including Allpoint Systems LLC, Firehole Technologies Inc., Tinkercad Inc., and Virtual Shape Research GmbH.
With the Delcam deal, which was finalized in early February, Autodesk is attempting to move designers and manufacturers closer together using better Design-for-Manufacturing solutions (see our Software Update Password interview with Carl White, Autodesk’s senior director, manufacturing engineering, in the February 2014 issue of Manufacturing Engineering).
More Integrated CAM Solutions
After acquiring CAM developer HSMWorks in 2012, Autodesk last November released an updated HSMWorks 2014. That integrated CAM solution forms the core of the company’s new cloud-based CAM 360, a product introduced in December at Autodesk University in Las Vegas. Integrated CAM solutions have always been highly popular with job shops, said Anthony Graves, CAM product manager, Autodesk Inc. (San Rafael, CA), but the less-expensive integrated CAM packages are now much more capable of competing with major developers’ stand-alone CAM systems.
“The single biggest shift in CAM has been a move to integrated CAM for mainstream desktop users,” said Graves, who previously worked with CIMCO and the Copenhagen, Denmark-based HSMWorks development team. “We heard from end users what they were looking for in a CAM solution as far as usability, and we recognized that designers and engineers were more and more becoming involved in the manufacturing process, if not directly involved in the prototyping process on CNC machines because of this whole push of Design-for-Manufacturability.”
During the development of HSMWorks, Graves said “we needed to understand how we design better products, and part of that is understanding how products are made. Companies were literally forcing these two groups of users, who had previously been divided by this invisible wall, to work together to come up with better solutions and better products and more economically manufacturable products.”
Given the option of an integrated solution, Graves noted, people opt for an integrated CAM solution because they can learn the system faster, it’s easier to do cross-training, and data exchange and data management are much smoother. When developing HSMWorks “we said if we could do this right and come up with a seamlessly integrated solution that offers users this transparent workflow where they can’t tell where the CAD tools end and the CAM tools begin, we are going to pave a path for designers and engineers to get into the manufacturing world,” Graves recalled. “They won’t have to learn a new interface, the tools won’t be intimidating, and we will make it easy for them to be successful in CAM.”
Autodesk began beta-testing CAM 360 last December, Graves said, and a commercial version of the cloud-based CAM is scheduled to be available later in 2014. CAM 360 includes the company’s basic Fusion 3D modeling capabilities, and the system also is available with up to five-axis machining functionality in a tiered pricing model.
Improved Machine Simulation
With the proliferation of multitasking machines and more five-axis machining, manufacturing operations need better machine simulation capabilities to deal with programming complexities. The latest CAMWorks 2014 release added a new module that offers users seamlessly integrated true G-code machine simulation, noted Vivek Govekar, R&D head, Geometric Technologies Ltd. (Mumbai and Scottsdale, AZ).
Using true G-code simulation and verification dramatically speeds up machine setup times, Govekar said, and helps users machine their parts right the first time. “Time-to-market is the key competitive edge that customers are seeking today,” Govekar said, “and the ability to verify their work, literally with the click of a button, is definitely a big advantage for them.”
The CAMWorks simulation and verification adds a lot of value for multitasking systems that have multiple turrets, he added. “The important thing is it’s based on G-code,” Govekar said. “You see a lot of systems around with simulation, but they’re all based on CL [cutter location] data. For simpler scenarios, with no sub-programs, canned cycles or advanced tooling, that may not be a big deal but for today's sophisticated machine tools, it is an absolute necessity.”
Machine simulation is increasingly important, noted Steve Sevitter, regional director—Americas, Vero Software (Cheltenham, UK), developer of CAM software including the EdgeCAM, Machining Strategist, Sescoi, Surfcam, and WorkNC packages. “The latest five-axis or multitask machines are a ‘collision-rich environment’ with a high risk of a clash between part and machine, or even machine head to table,” Sevitter said. “Advanced machine simulation can both avoid these collisions, plus reduce machine time by allowing the user to optimize the toolpath.”
In aerospace machining, highly accurate machine simulations are mandatory. With the Dassault Systèmes V6R2014 suite of CAD/CAM applications, aerospace users can now take advantage of full machine simulations before taking product designs to the shop floor, noted Jean-Marc Cauzac, Delmia Manufacturing Consultant, senior machining expert, Dassault Systèmes (Paris), and it’s important for software developers to work with customers in tight process integration on designs both upstream and downstream before going to the factory floor.
“The main development today is on the specific application,” Cauzac said. “In the aerospace domain, one of the biggest requests is from customers machining structural parts with a lot of pockets. People are machining pocket by pocket, and machining that manually. But today we are delivering an operation that is able to do that automatically.” With Delmia’s V6 Machine Builder and related applications, users can accurately visualize aerospace bulkheads, wings or other structural components as well as all the machine tool elements prior to cutting components.
Multitasking and Swiss-style machines continue to be very popular and are available with increasingly dynamic configurations, said Dave Bartholomew, product manager, DP Technology Corp. (Camarillo, CA), developer of Esprit CAM software. “More than ever before, we’re seeing an increase in the complexity of machined parts, more advanced and complex machine tools, and heightened complexity in NC programming,” Bartholomew said. “As a means of contending with the increasing complexity, CNC programmers are looking for a complete programming solution—one that is easy and intuitive to use, takes full advantage of the capabilities of their machine tools, and produces accurate NC code.”
Ensuring a complete solution means providing a realistic representation of the machine tool for simulation and verification, including the ability to see all axes’ movements and, in cases of potential violations, the opportunity to easily make corrections, he added. “It also means providing a user interface that easily and reliably allows the user to take full advantage of all the machine tool’s capabilities. And while the former two points are important, the most vital attribute of any CAM system is its postprocessor,” Bartholomew said. “The simulation on the screen must match what happens at the machine tool, he added, and accurate G-code is directly dependent upon a complete postprocessor. The goal is to push a button and see G-code, with no edits required.”
Leveraging Machine Kinematics
For the ultimate in machine simulation, some CAM software uses machine tool kinematics to more accurately describe machining movements in very rich simulations. “The biggest project that’s coming to fruition for us is the UKM, Universal Kinematic Machines,” said Bill Gibbs, president, Gibbs and Associates (Moorpark, CA), developer of GibbsCAM. Gibbs’ UKM, which will be out sometime in 2014 for the next GibbsCAM update, allows the software to give users a true representation of any machine configuration, Gibbs said, with very accurate simulation of kinematics of highly complex multitask machining (MTM) systems.
The GibbsCAM UKM system is not lathe or mill-focused, he said, and it programs multiple-flow toolpaths, simulates and creates postprocessors for any machine configuration. “One of the problems we have is we’re addressing a problem that the market is not particularly educated on,” Gibbs said. “A lot of our customers do basic milling and turning. Every release we put out is divided between doing basic improvements and future technology updates.”
Other CAM software developers have worked on similar machine kinematics projects. “One of the most fascinating technologies we’ve developed is the incorporation of the kinematics of exact machine tools, creating virtual machine tools on which the knowledge of the machine is used for not only simulation, but for toolpath calculation,” said DP Technology’s Bartholomew. “The knowledge of the machine’s kinematics and dynamics can be used in programming by incorporating program coordinates and feed rates to optimize acceleration and velocity while eliminating jerk.”
Today’s CAM software relies upon a CNC programming model that dates back to the 1960s, Bartholomew noted. “This methodology is a geometric approach that uses little more than the definition of the part and stock to calculate the resulting toolpath. An evaluation of the CAM systems on the market today reveal that this model has not evolved since the inception of CNC controls,” he said. “Esprit offers a more complete knowledge of the entire machining process, as well as a data-driven, highly optimized and more efficient toolpath-generation engine.” This new technology will overcome many limitations innate to all CAM systems, he added, particularly in the field of five-axis machining.
Simulating 3D cutting-tool models also has become increasingly important in recent years, according to Bill Hasenjaeger, product marketing manager, CGTech (Irvine, CA), developer of the popular Vericut NC simulation/verification/optimization package. Cutting-tool developers Kennametal, Iscar and Sandvik all have projects in various states of completion, projects intended to supply 3D tool models to end-user customers.
“It’s interesting for us to see this evolve and become available since CGTech has advocated tool manufacturers supply 3D cutting tool models for many years,” Hasenjaeger said. “Machining simulation requires 3D models of cutting tools and is a critical link of the automated CNC machining process chain. Machining path generators only use parametric descriptions of the cutter, not the 3D model. Some toolpath generators have provided visualization of 3D models along a path for years, but this has little practical utility. Broad industry acceptance of CNC process simulation [and customer pressure] has finally provided enough incentive for cutting tool manufacturers to do the work to provide these models.”
Embedding CNC machining process simulation in the manufacturing engineering process chain also has been a recent recurring theme, he added. “Vericut is used by a lot of large and mid-sized manufacturing companies with resources to automate its use in their processes,” Hasenjaeger said. “Fortunately Vericut has a broad suite of automation features and we’re sensitive to how valuable this is to our end users. In fact, we use Vericut’s automation features in our own internal product testing methods. When used in this way Vericut becomes a kind of ‘go’ and ‘no-go’ gage to test NC programs.”
Programming for Maximum Efficiency
To optimize productivity, CAM software gives manufacturers many ways to try to cut costs when automating machine tools. “We think the first thing that a business should look at is money, and when you look at money, the first cost is machine time,” said Gibbs, who believes shops must be aggressive in analyzing overall machine time. “If you want to utilize your machines more, another thing you have to look at is your human labor component. It costs money to have somebody standing by every machine.”
Automation improvements with optimized cells, automatic probes, and pallet changers can help reduce machine downtime, Gibbs noted. “CAM software has the potential to make sure that you don’t take problems to the machine,” Gibbs said. “With simulation, you can check to ensure you have all your tooling presets, make sure the programming concepts are validated, and spend much less time checking programs for errors.”
The latest GibbsCAM 2014 offers improved five-axis machining with two 5-Axis MultiBlade options for machining of turbomachinery components such as impellers, blisks, and blings. The software also incorporates the latest versions of the VoluMill toolpath optimization for roughing toolpaths to speed up machining.
High-speed roughing from Delcam is now available in PowerMill 2014 with the company’s new Vortex high-efficiency area clearance strategy. Delcam’s patent-pending Vortex “takes a different approach to other apparently similar developments as it is based on maintaining a controlled angle of engagement and so allows a near constant feed rate for cutting moves, rather than focusing on aiming for a consistent metal-removal rate with varying feed rates,” said Peter Dickin, Delcam marketing manager.
A key trend is more widespread acceptance and adoption of “dynamic” style toolpaths, said Steve Bertrand, sales manager, CNC Software Inc. (Tolland, CT), developer of Mastercam. “It’s a technique we’ve been developing and expanding for the last five years. These toolpaths use more of the tool and allow deeper cuts, delivering faster machining and less tool and machine wear.”
Programmers also need a full understanding of a part’s changing stock model, Bertrand noted. “Using the changing stock model to automate and streamline subsequent operations helps create the most efficient motion possible. This is especially useful with mill-turn machines and repositioning for multiaxis manufacturing.
“NC programmers are a unique mix. They tend to be smart and forward-looking, while still being strongly practical,” Bertrand said. “This results in users looking for both new technology they can exploit as well as a constant improvement of established techniques.” ME
This article was first published in the March 2014 edition of Manufacturing Engineering magazine. Click here for PDF.
Published Date : 3/1/2014