At its Mulhouse plant in Alsace, PSA Peugeot Citroën depends on hyperMILL, a CAM/CAD system from OPEN MIND Technologies AG. The car manufacturer produces aluminium moulds and tools for forging and thermoforming at the plant. Since introducing hyperMILL, PSA has benefited from the numerous options for automation offered by NC programming.

In the past, PSA employees had to write their own macros if they wanted to make it easier to program recurring geometric shapes. The macros were time-consuming to maintain, and constantly had to be adapted to new software versions. In the search for new CAM software, hyperMILL stood out as the obvious choice because it offers numerous options for automated programming; intelligent macros are just one example. Today, the software is being used in all areas.

“hyperMILL® is a forward-looking solution offering innovative technologies for 2D, 3D, HSC, mill/turn and 5x machining. We were impressed by its intuitive user interface, its simple and transparent management of complex processes and its straightforward way of including user-defined macro instructions and maintaining them in later versions,” reports Laurent Sifferlen, who is responsible for tool and CAD/CAM quality in the PSA workgroup.

Serge Locher, a programmer at PSA, explains: “We were able to automate the transfer of CAD models from CATIA, and discovered in the process that we were able to eliminate all of the sources of errors that can arise during automation, for example during drilling. We could reuse our macro instructions for drilling or machining work and use them to create new instructions directly in hyperMILL.”

Roughing with hyperMAXX
The PSA plant in Mulhouse employs hyperMAXX, a high-performance cutting module. Fully integrated into hyperMILL®, this roughing module ensures optimal milling paths and maximum material removal. It translates into time savings of roughly 30 per cent for PSA, while also drastically reducing wear and tear on tools.

Over the years, manufacturing processes have progressed steadily with the advent of technology. From an initial reliance on physical labour, manufacturers today are increasingly turning to more sophisticated means in their pursuit for efficiency and better results.

One of the main computer-aided manufacturing (CAM) applications in metalworking is nesting;the process of arranging cut profiles within a given area (typically on a flat metal sheet) to maximise material utilisation. The nesting software analyses the parts to be produced and, with the use of proprietary algorithms, determines the best way of laying out these parts with minimum raw material waste. Nestingis often used in industrial manufacturing processes, such as the manufacture of metal parts for machinery.

Changing requirements in modern nesting
In the past, the concept of nesting merely involved filling a metal sheet with cut profiles, but along with technological advancements and increasing demands for productivity, this concept has evolved. The complexities of modern manufacturing meant that the nesting process is now more than just a simple geometric problem of arranging parts on a sheet. And often times, nesting in sheet metal poses far greater challenges, compared to other industries, for three main reasons:

Complexity of parts
Machinery parts are often complex and irregular in shape. Furthermore, modern manufacturers may have nesting jobsthat consist of a mix of parts for different customers. The angle of rotation of the various parts also has to be considered during nesting to ensure correct metal grain direction, while also providing effective material utilisation.

Different sheet sizes
Today, sheet metal is available in a wide selection of stock sizes. Depending on job requirements, manufacturers may have to work with sheet metal of varying dimensions. At times, in order to minimise waste, manufacturers may even choose to cut smaller parts from sheet remnants, which are often irregular in shape.

Maximising both sheet utilisation & time
For a given set of metal and parts to be cut, there will be various nest options available, even without considering part rotation. The challenge lies in identifying a particular nest that provides the optimal balance of sheet utilisation and cutting time.

Manufacturers are increasingly adopting a lean manufacturing approach for optimal efficiency and cost savings. This demand for greater productivity, coupled with the above-mentioned challenges, have led to the need for more sophisticated nesting software that can offer additional benefits.One such software is Hypertherm’s ProNest®, an industry leading CAD/CAM nesting software for advanced mechanised cutting.

Advancements in nesting software
Compared to traditional nesting software, advanced nesting options confer several major benefits that ultimately lead to increased efficiency, better cut quality, and an overall improvement in the manufacturing process.

Materials optimisation
For manufacturers, keeping production costs low is always a priority, and one of the ways to achieve this is by maximising usage of materials. By considering the actual shape of the cut profiles (both regular and irregular) before nesting, advanced software are capable of automatically developing a layout of selected parts on the sheet metal, with optimal part spacing and orientation to maximise plate utilisation.The software is also intuitive enough to utilise spaces with in existing parts (Figure 1).

Furthermore, operators can easily create remnants, either cropping the plate and saving them electronically in the software, orby entering the dimensions of an irregular plate found in the manufacturing facility and adding these dimensions to create a remnant for immediate or future nesting (Figure 2). This way, leftover material can be re-used for other jobs. Software such as ProNest also have additional capabilities that make advanced-level nesting decisions based on the parts available. This way, manufacturers face fewer challenges when identifying the nest that gives the best sheet utilisation, as the software is capable of selecting theoptimal nesting option.With nesting software that offers such capabilities, manufacturers will be able to utilise materials more efficiently during the manufacturing process.

Increased productivity
While efficient nesting is desirable, having the ability to cut these nests productively is another important consideration. Different continuous cutting functions that connect two or more profiles to form a single cutting path are now incorporated into some advanced nesting software, allowingmanufacturers to cut their nests with ease. For example, common line cutting arranges and joins any number ofparts, with one or more straight edge,together so that the parts can be cut with a common line (Figure 3). Chain cutting provides a way of linking a variety of parts with a continuous cut, whereas bridge cutting allows two or more parts to be linked by a thin web of material (bridge). Besides increasing productivity, these processes also reduce the pierce cycle, which saves time, extends consumable life, and lowers production costs.

Better part quality
With advanced nesting software, process-specific parameters like pierce rate, feed rate, and kerf compensation can be varied during the cutting process. All these factors contribute to cut pieces with improved edge quality, reduced dross, reduced hole taper, and sharper corners.

Apart from simply laying out cut profiles during nesting, some software comes with additional features that are capable of detecting nesting conflicts and job errors. These pre-cutting checks ensure that the job is properly completed the first time, thereby avoiding the need for secondary processes like grinding.

Versatility
Within a single manufacturing facility, cutting processes may differ from job to job, based on the material thickness or job requirements. For advanced nesting software, application is not limited to a single cutting process as the technology is compatible with multiple cutting processes, including plasma, laser, oxyfuel, waterjet, or combination punch, regardless of cutting machine brand and model. In addition, some nesting software allow operators to have control over advanced metal cutting applications like bevel and hole cutting, with specialised built-in support that enables these features to be utilised automatically without operator intervention. Manufacturers will thus be able to consolidate all cutting processes into a single software solution, so less time and resources are required for software training.

When it comes to nesting software requirements, there is no ‘one size fits all’ solution, as cutting needs can vary greatly, even within a single manufacturing facility. Hence, the appeal of advanced nesting software lies in its modular structure, as manufacturers are given the option to customise their software, including only the features and modulesthat they require. This versatility translates to greater cost savings for manufacturers in the long run.

Integration
In order to fully utilise the benefits of nesting software in a modern manufacturing environment, integration with other corporate business systems within an organisation is vital.Today’s advanced nesting software offersquick and seamless integration with most Enterprise Resource Planning (ERP)/Manufacturing Resource Planning (MRP) solutions through data sync capabilities that provide fuss-free plug-and-play integration. For instance, work order processing allows operators to process work orders, such as parts grouping and tracking, directly from within the nesting screen, instead of relying on manual input. When integrated with a plate inventory system,a good nesting software will allow manufacturers to effectively managetheir sheet inventory, while ensuring that only availablematerials are used. These are just some ways in which advanced nesting software can contribute to a lean manufacturing business approach.

Conclusion
Nesting software has come a long way since it was first developed, and today, it is no longer sufficient to view it as a purely geometric solution. Advancements in technologies have opened up a new array of possibilities in nesting processes that touch on increasingly more aspects of a manufacturing business. For companies looking to achieve a lean manufacturing approach, advanced nesting software like Hypertherm’s ProNest can add considerable value to a business and assist manufacturers in achieving high quality end products with greater efficiency and cost savings.

Author: Tom Stillwell, Sr. Marketing Specialist, Hypertherm CAM Software Team

CAD-CAM software now provides a high speed machining advantage that CNC operators can profit from. 

Now that CAM programming and high speed machining have been around long enough for shops to recognize CNC production increases as high as 50% or more because of it, there are still shops out there that need the dirt before the glory. So here is why you should be programming with CAD-CAM software that offers High Speed Toolpath strategies.

Some History First
Years ago, in the beginning of NC, each block of data was executed in order, one at a time. Speeds were sufficiently slow that this was a workable arrangement, especially for drilling and 2D linear milling operations. It was when the machine needed to execute a curve or contour that the need arose for seeing what kind of data was ahead in the program. Otherwise machine momentum would cause the cutter to overshoot or undershoot a programmed change in cutter direction, wreaking havoc on the workpiece. That need lead to the development of look-ahead, which is requisite for high speed machining of any geometry except for linear, single-axis moves. If your CNC controller doesn’t have a look-ahead feature, it needs to be upgraded for high speed machining. In 2014 there are many affordable solutions to this such as Mach3 by Artsoft that can help ramp up those older machines.

Traditional Offset versus High Speed Toolpaths
The term, “Toolpath” is used to visually display and describe the route in which the CAM side of the software tells the cutting tool to machine the geometric regions of the part model. It’s the path that the tool takes when machining. Toolpath is going to be basically being defined by the part or areas that the user has chosen to machine, the size of the tool being used, the cutting regions for those tools and the type of machining strategy that is used. That is toolpath whether it’s for a mill, router, laser, burning machine, waterjet or CNC lathe. There is a lot of other data that is included in the creation of a NC Program that has to do with post processing parameters such as speeds and feed rates based on strategy, material and tool data and more. Machine controllers can be different in how they want to see the g-code for the program to be read properly by the machine controller. That is toolpath.

More than one toolpath is typically used to perform machining operations. Generally this will be a “Roughing” and a “Finishing” operation. Roughing is generally the first stage of machining.

This is where multiple step downs by the tool, remove the bulk of the material.

The second operation will be the finishing operation to complete the machining phase. There is also “Semi-Finishing”. An example of this would be the use of a Z-Level Roughing operation to remove the bulk of the material. Then a Z-Level Finishing operation to “semi-finish” the part and lastly a “Equi-Distant Offset contour” operation to finish the part off.

By employing the use of High Speed toolpaths into your machining operations you can achieve excellent results faster than by using traditional offset toolpaths. Even in the world of 3D machining.

BobCAD-CAM software offers a unique Advanced Roughing operation that includes the option to use an Adaptive High Speed machining technique. This was specifically added to give the programmer an advantage in roughing out 2D or 3D regions of a part, or the entire part. Boundaries can be created and used to segregate the toolpaths into specific regions of the part, deep cavities or regions that require a smaller tool to machine. This would not be used to replace a REST operation. An advanced REST machining operation would be used as a part of the finishing process to clean up areas where the larger tools were unable to machine.
Traditional offset toolpath has been the most common form of toolpath in use since the advent of CAM software. However, as more and more shops begin to use HSM they are trusting it more, becoming less critical and beginning to enjoy the benefits of it. The goal of using a trochoidal form of machine path is to limit the number of collisions that the cutting edge of the tool has with the material, reducing chip load, better utilize the cutting tool itself by using more of it while taking deeper cut depths and all while at much higher speeds.

There are distinct differences in toolpath operations, planar (1), offset (2)and high speed (3). Here you can see each of them in a simple 2D example.

Planar (1) is the most fundamental of the three and is basically a back and forth slice across the material. Options for this style of toolpath would include the ability to machine in one direction (zig) and back and forth (zig-zag). You should also be able to determine a cut direction (climb or conventional), determine a “Lace Angle” parameter and a step over for the cutter. Some CAM systems will allow you to include a side allowance and a bottom allowance so that material can be left over for a finish pass. Tool lead-ins and lead-outs will often times be limited to a plunge, ramp or a spiral lead-in when using this type of strategy, each option definable through input parameters. In addition, compensation controls can be available for the finish pass. These options would include the availability of a complete tool database/library with tool crib and tool holder libraries as well as a complete material database/library. CAM software is designed to organize these strategies and associated variables. BobCAD-CAM has developed each machining operation into “wizards” that step the operator through the procedure so that the features are organized and no variable is left behind. This makes the process easy to understand and get through.

In addition, the CAM software allows for the overwriting of system tool parameters so that the experienced operator is not limited. These would include the use, or not, of system tools, tool height and offset values, speeds and feed parameters for the operation. These operations should also allow for the slowing down of the tool when entering an arc corner (when not using HSM).

Offset (2) is most common in CNC machining open or closed wall pockets and slots in a 2D/2.5 Axis (X, Y and Z step down) program. Very similar to planar, this type of operation in a CAM system is going to have the same variable inputs. The difference is whether you want to create an offset IN or an offset OUT. These concentric offsets will either start outside working their way toward the center of the specified cutting area or start in the center and work their way toward the outer wall or defined area.

All of these operations in a CAM program will also include single step or multiple step options. This is where a total depth is either automatically calculated based off of the part model or manually input by the programmer. A depth of cut is entered and the CAM program should automatically calculate the number of Z-Cuts needed to machine (rough) the part region.

The offset toolpath will typically have many right or left turns where there can be a lot of stop and go occurring with the tool while machining. The more times this happens the more wear and tear there will be on the tool. Often times this type of toolpath will produce higher levels of vibration as well and require spending more money on tooling for jobs that have cutter designs that minimize heat in the cutting zone in order to reduce power consumption as well. Offset toolpath can lead to higher rates of tool deflection which can also lead to parts being cut out of tolerance and poor surface finish results. This means that higher speeds and feeds often times cannot be used. While offset toolpath can be very useful, it is the High Speed toolpath strategies that provide the greatest benefit.
High Speed (3) machine toolpath strategies, also known as “Trochoidal” machining toolpaths open the door to a number of important benefits such as:

• The controlled arc of engagement generates low cutting forces which enable high axial depths of cut. Multi-edged tools can be used which enable high table feeds with secure tool life. In other words, deeper cuts can be achieved easily.
• The whole cutting edge length can be utilized ensuring that the heat and wear are uniform and spread out, leading to longer tool life.
• There is a constant tool engagement, deeper cutting and NO stop and go.
• High Speed toolpaths are excellent for slotting and pocketing when vibration is a problem.
• Much higher speeds are used resulting in superior finishes due to a number of factors (reduced tool deflection, vibration/chatter etc.)while machine cycle times are vastly reduced. Shorter cycle times on jobs.

Most shops are cutting faster today than they did ten years ago. Albert Einstein said it first and best, “All motion is relative.” From that perspective, incremental improvements in “rate” mean that a shop is machining at high speeds relative to what it did previously. Increasing the feed rate of a ball-nose end mill in tool steel from 12 to 24 ipm and spindle speed from 4,000 to 8,000 rpm is a 100 percent increase in cutting speed and well within the capability generally found on most CNC machining centers.

In addition, as the cutter creates a chip, the heat generated by that action is transferred to the chip. When the chip breaks and leaves the cutting zone, the heat is carried away with it. A big advantage of high speed machining is that at elevated rates of speed and feed, the chip is cut and evacuated so fast it tends to transfer little or no heat to the green workpiece. In many cases this eliminates the need for coolant. At conventional machining speeds, there is time for heat to move from chip to uncut metal and create a work-hardening condition.

This increases the force needed to create a chip, which creates more heat, and so forth. Coolant mitigates the cycle by reducing the temperature in the cut zone and flushing away the chips. However, at very high rpms, the tool rotation throws coolant away from the cut zone so without very high pressure or through-the-tool piping, it never reaches the cutting zone. Trapped chips can remain in the cut, allowing them to be re-cut by the tool. Therefore, an air blast is very efficient for evacuating chips in high speed applications.

High speed machining can certainly help a shop manufacture more accurate parts with better surface finishes. And often, because a machine tool and workpiece setup has to be very rigid for high speed machining, the results are more consistent workpieces. All of this together amounting to higher efficiency in CNC programs, machining and in the end, increased profitability for a CNC business.

Taking The High Speed Route To CNC Profitability
We really do not see a training book that specifically addresses high speed machining and CAD/CAM together. However, CAD/CAM software is an absolute necessity for the creation of these types of machining toolpaths. Without CAD-CAM software they wouldn’t exist today. The benefits listed in this paper outline all of the reasons why shops should take advantage of this technology. And now, high speed adaptive roughing strategies being available through BobCAD-CAM for Multiaxis CNC machining for the first time, opens the door for even more complex CNC work to take advantage of its powerful abilities and profit-building results. Machine time is money and the reduction in cycle times that lead to faster turn-around, happier customers, better finish results, reduced tooling expenses and a longer life for your CNC machine tool all equal profit and better business practices.

Delcam’s Illinois office presented the latest developments in the company’s PowerMILL CAM system for high-speed and five-axis machining and its FeatureCAM feature-based programming software at its annual update meeting earlier this month.

The meeting was held at Ingersoll Cutting Tools in Rockford and included live cutting demonstrations on Ingersoll’s Mori Seiki MV-65 and Toyoda UX570 CAT 40 machines. Both demonstrations showed the machining of a metal replica football, one programmed with PowerMILL and one with FeatureCAM. Recognizing the divided loyalties of the region’s Delcam customers, one was produced with a Chicago Bears theme while the other featured the Green Bay Packers. Part of the engraving process can be seen here – www.youtube.com/watch?v=ER8LR4-z4P0

The new release of PowerMILL includes improvements to the Vortex high-efficiency area-clearance strategy, expanded collision checking to also cover near misses, and more efficient raster finishing.

Vortex produces safe toolpaths with a much deeper cut by using a controlled engagement angle that maintains the optimum cutting conditions for the whole toolpath. As a result, higher feed rates and material-removal rates are possible, making the cutting time shorter by as much as 70%. Enhancements in PowerMILL 2015 will give even greater reductions in machining time with Vortex compared to conventional roughing.

Companies using four- or five-axis machines with trunnions or similar tilting tables will benefit from new options are now available to distribute PowerMILL’s toolpath points so that the machine’s gimbal-lock position is avoided and a smoother motion results.

As well as including the latest developments in the Vortex strategy, the 2015 version of FeatureCAM incorporates a range of enhancements in three-axis milling, two-axis and five-axis drilling, turning and turn-mill, and wire EDM to make the software even more powerful and easier to use.

FeatureCAM was the world’s first feature-based programming software when it was launched in 1995. Constant development since then has ensured that the system has retained its leadership in programming speed and ease of use, while an increased range of strategies has been added to provide more efficient toolpaths that give greater productivity on a wider range of machinery, including mill-turn machines, five-axis mills and wire EDM equipment.

The Technical University of Liberec has introduced the second generation of its special service robot, the ROBOTUL® Vertical Climber 02, which uses a unique stepping movement to traverse both smooth and structured surfaces such as the glass walls of buildings. Its safe and highly precise operation is guaranteed by an advanced B&R control system with compact ACOPOSmicro servo drives.

The new approach taken by the Institute for Nanomaterials, Advanced Technologies and Innovation ensures linear movement, track stability and smooth rotation while enabling the robot to step over discontinuous surfaces and mounting holes. It can move with a high degree of safety on vertical – and even negatively sloped – walls. Based on feedback and experiences with its predecessor, this new generation is being developed in the context of the 3-year pre-seed project “New Technologies and Special Machine Components”.

Wide range of applications
The Vertical Climber 02 is designed to clean walls and perform surface inspections such as checking mounting points on glass panels or checking the integrity of stainless steel pressure vessels. It can also be used as a mobile platform for other technology, including cleaning and dust-removal equipment. The robot has compact dimensions of 112x112x30 cm and weighs 48 kg. The maximum workload for the robot is 20 kg. Up to 80 sq m can be cleaned per hour, or up to 90 sq m inspected.

The body consists of a compact duralumin frame with a rotary servo drive connected to a rotary chassis. Its four moving legs are each driven by a separate rotary servo drive. The duralumin frame and the legs are equipped with articulated active suction caps combined with smart ejectors. Multiple smart sensors identify the position of the robot in space and with respect to the contact wall plane.