Simulation Ramps Up
Advanced visualization tools help manufacturers boost efficiencies
By Patrick Waurzyniak
Everybody’s getting into the simulation game. Machine-tool CAM software suppliers and machine control vendors are joining NC simulation/verification software developers in enhancing CAM and controls offerings with more advanced simulation capabilities, enabling manufacturers to easily visualize machined parts before cutting any metal.
With the latest systems, machine tool customers and CAD/CAM software users can look forward to full-machine simulation tools, as well as NC simulation/verification capabilities, for improving manufacturing productivity and optimizing machining processes.
Simulation’s advances shown at IMTS in Chicago include adding new visualization elements into controls gear from leading suppliers GE Fanuc Automation Americas Inc. (Charlottesville, VA) and Siemens AG (Munich, Germany, and Elk Grove Village, IL), and CAM software suppliers featuring the full machine-simulation capabilities in the latest CAM packages.
At IMTS, GE Fanuc introduced its new Manual Guide i Simulation Software, a Windows-based shop-floor programming package that allows users to simulate the CNC operator interface off-line. Aimed at simplifying complex programming, the software features 3-D machining simulation for both turning and milling, helping reduce the time for part-program checking and reducing errors.
“The transformation we see is that it’s always important today to try to simulate the part being machined before the cutter ever touches the part,” says Jim Spearman, GE Fanuc’s Manager, Machine Tool Solutions. “This is a very powerful, visual graphical tool that allows you to see any errors or collision points. This type of HMI with simulation allows you to do a full 3-D model and simulate the part you’re going to machine before you actually machine that part, and potentially make a mistake.”
For some time, customers have wanted the ability to use GE Fanuc controls’ features off-line, notes Spearman, and with the new simulation software, customers now can use all the features and characteristics of a GE Fanuc CNC on the shop floor while working off-line in an office or educational facility. “You can now transport that capability into the classroom and do complete CNC simulation from a graphical cutter-path solid model remotely from the shop floor inside a PC or on a laptop.
“The operator has the ability, if required, to create that part program through geometry entries at the shop floor,” Spearman adds, “and it will create one of two things: it can ultimately create what you called a G-code program, or it can create what can run internally in the control as a high-level macro-type program. And the concept is to take that CAD/CAM-type simulation that engineers have enjoyed for years and bring that out into the shop-floor environment where the operator can actually get that visualization.”
Simulating the control offers advantages directly related to reducing manufacturing costs and time-to-market. With Siemens’ new Virtual Production and Mechatronic Support services demonstrated at IMTS, the controls supplier can use simulation to help customers increase workpiece quality and dramatically shorten production times. Based on software developed by Siemens, the process chain is subjected to a simulative analysis from the CAD/CAM system to the workpiece surface.
In a virtual manufacturing collaboration with NC simulation/verification software developer CGTech (Irvine, CA), Siemens announced its partnership with CGTech to tightly integrate CGTech’s Vericut simulation/verification software with Siemens’ Sinumerik CNCs. As a result, the companies have integrated the Vericut software with Siemens’ Virtual Numerical Control (VNCK), software that is used for part simulation and verification and contains the NC portion of the CNC run directly on a PC. Implemented as a stand-alone Windows program, the Sinumerik 840D control’s NC kernel motion logic is built inside the VNCK, which communicates with Vericut and drives the Vericut simulation by moving Vericut’s virtual-machine axes using the same motion algorithms used by the actual control’s electronics.
| With a new process inspection tool, CGTech’s Vericut 5.4 enables users to capture valuable process information generated in its simulations to produce automated inspection reports.;
“With this technology, manufacturers can simulate a complex part, such as a mold, which saves them time and money,” says Wolfgang Rubrecht, general manager, Siemens Machine Tool Business Unit (Elk Grove Village, IL). “If it doesn’t come out the way they want, they have to scrap it. So with a virtual part, they can see if the program that they have generated yields the result that they expect.”
“The VNCK/Vericut integration is another facet of the long-standing close relationship between Siemens, CGTech, and our mutual customers,” says Bill Hasenjaeger, CGTech product manager, noting that CGTech has been emulating the Siemens 840D control since 1996 and developing technologies that accurately simulate CNC machines equipped with the 840D control. “The connection to the VNCK provides a new method to drive Vericut’s CNC machine simulation, ensuring correct motion for 100% of the 840D control’s advanced features, unique motion control techniques, and high-level programming options.”
In NC simulation/verification, CGTech also recently updated its Vericut package with Version 5.4, which improves the CNC simulation documentation process by adding several features including an automation inspection tool. Since Vericut simulations generate critical manufacturing information, especially in-process geometry, which is necessary to document the process, CGTech added the process-inspection report tool, which enables users to generate .html or .pdf files documenting the process. “We’re always trying to look for ways we can broaden our appeal outside of purely the NC departments,” adds Hasenjaeger. “This was a good way to do that, because we already had all this information, we just needed to expose it.
“The inspection tool was a collaboration between us and an Airbus division in Germany,” he adds. “They wanted to create an inspection document out of Vericut, because when we run the simulation in Vericut and it cuts the part, we produce these nice accurate features of where it made the cut. This gives users a tool where they can click on these cut features, and it extracts the geometry, the dimensions of those features, and puts them in inspection reports. You can say ‘Inspect this hole,’ and it takes the hole diameter as simulated in Vericut and plunks it in the report. So rather than someone fat-fingering in a number and making a mistake, they’re actually pulling it right off of the simulation.”
Over the past year, CGTech also has refined several key features in Vericut, with its prior version adding a revamped CNC machine probing capability and a new milling verification technique said to be up to 5-10 times faster than the earlier method. The Vericut FastMill mode supports ‘fixed-tool axis’ material removal at any tool orientation around the workpiece.
Designed for large NC milling programs, Vericut’s FastMill is aimed at NC programs with many short motions typical of mold-and-die machining, Hasenjaeger says. “People don’t really need or care to see the animation as much as they want the end result of each cutter, and to be able to have Vericut catch any errors that occur.
“The faster algorithm gives our customers with large NC programs a much better tool for verifying and optimizing NC programs,” he adds. “It enables them to shorten NC program prove-out and optimization time, so they can produce more efficient programs faster and get their products to market more quickly and competitively.”
Simulations aiding process improvements and targeting reductions in time and cost for machining operations are at the core of new software solutions from Delmia Corp. (Auburn Hills, MI), a subsidiary of Dassault Systèmes SA (Paris). With Delmia’s new End-to-End (E2E) Machining Solutions announced at IMTS, the simulation software developer released a suite of applications that encapsulate activities in the machining process, including process planning, NC programming, and NC verification and inspection.
With Delmia’s Process Engineer, a project is initialized in the conceptual product design phase, capturing logistical information, such as location, labor, production shifts, production volume, and budgets, and then integrating the data into Delmia’s Manufacturing Hub to facilitate all ongoing communication and collaboration. In Delmia’s machining simulation offering, manufacturers can quickly and efficiently verify both parts and processes to reduce man-hours, increase machine utilization, and improve product and process quality. Part verification features material-removal simulation and analysis of machined parts based on toolpaths, which can also be verified from a process perspective by simulating machine movements to detect potential toolpaths collisions even before the NC code is generated.
“In the past, we have started with the individual point solutions, solutions for a specific machine, how to program and get the most efficiency out of the machine,” says Peter Schmitt, Delmia vice president of business development. “What we are seeing is that companies are starting to look at the entire portfolio of what they have to manufacture, and define the processes that have to be done, based on all the machines they have available, to get highest quality and the highest efficiency out of their production equipment. If you are a small shop with only one or two machines, the point-solution approach is still valid.”
Delmia’s earlier point solution for NC simulation and verification, called Virtual NC (VNC), will be replaced with the new product line, which Schmitt says the company already supplying to customers. Delmia will offer its new Machine Toolpath Simulation, the equivalent of VNC, in its V5 offering within the next few releases, although Schmitt says its capabilities already are in production.
“In the past, you created your NC program, compiled and post-processed the code, ran the simulation in tools like our VNC, saw where the errors were, and went back in the NC program to make changes,” Schmitt notes. “On this compilation, you can see an immediate feedback with changes you’re doing in the NC program, how the machine tool reacts on this.
“Our target is to eliminate postprocessing,” says Schmitt. “Whether the market accepts this right away, our approach is to offer this for validating the postprocess program. Once you have done this through a number of programs and changes, and companies feel comfortable that it works as we’ve described it, then this new paradigm will be in place. Change is in the process of coming; we don’t see that the change has fully been embraced, but we see it coming.”
Full machine-tool simulation and toolpath simulations recently began showing up in the latest versions CAM software suppliers’ offerings, including Gibbs and Associates’ (Moorpark, CA) IMTS demonstration of GibbsCAM’s Machine Simulation optional module, and in DP Technology Corp.’s (Camarillo, CA) updated Esprit 2005 software.
With its Cut-Part Rendering, GibbsCAM has offered users toolpath simulation since 1992, notes Bill Gibbs, president of Gibbs and Associates, and the company is now adding its Machine Simulation, an optional module for GibbsCAM users demonstrated at Westec and at IMTS. “We continue to perfect this, but now we’ve gone into the full machine simulation, because still it’s very important for the user to be able to see exactly what he’s doing before he takes it out to the machine,” Gibbs notes. “The ability to completely verify the machine, its action, is all a way to save money, and keep those mistakes off the CNC machining.”
Machine simulation in GibbsCAM allows models of machine tools to be built to simulate and validate programmed machine-tool motion prior to actually running the CNC program. This enables operators to identify potential programming errors before they become very expensive mistakes out on the shop floor.
“This offers a chance to prove out the setup and the program prior to going out to a machine that costs $200 an hour or more to run,” Gibbs says. “We’ve always focused on making the program as good as possible before we get to the CNC machine. Machine simulation is just the next step in the level of detail that can be proved before taking machine time to do the proving. You’re still going to prove out the part on the machine, but you’re going to do it quickly and you’re going to find no problems-that’s the goal, 99.9% of the time.”
Dynamic solid simulation in DP Technology’s Esprit 2005 CAM software enables users to perform real-time simulations for verification of complex machining processes without taking machines off-line for expensive dry runs. The solid-simulation feature gives users new options for realistic views of the entire machine set-up, including part, fixtures, and machine tool. The simulation can be adjusted for collision control between parts and tools, toolholders, and the entire machine. Esprit’s machining action can be displayed in real-time with the choice of basing the simulation on the actual machine feedrates, while full, rapid, or rapid index simulations have been added for milling operations.
This article was first published in the October 2004 edition of Manufacturing Engineering magazine.