Shop Solutions: CAM Software Stuns the Competition
Since its founding nearly two decades ago, Taser Inc. (Scottsdale, AZ) has become the recognized leader in electronic control devices (ECDs). In fact, Taser ECDs are employed by approximately 80% of the police forces in the US, as well as by the military and security firms. Taser also produces civilian versions of the ECD as well as the Axon point-of-view video system for evidence gathering.
Few people realize, however, that along with building industry-leading products the company has earned a reputation for agile manufacturing as well. They’ve done this through the efforts of a highly skilled manufacturing staff, advanced CNC technology, and CAMWorks, the solids-based CAM software from Geometric Technologies (Scottsdale, AZ).
The R&D department at the world’s leading producer of electronic control devices is typically tasked with a large number of prototypes and other time-sensitive projects that have to be handled with speed and accuracy. Fortunately, they have help from CAMWorks software, which provides an array of tools to simplify and automate even complex programming tasks, speeding design and programming changes.
Milan Cerovic, advanced research designer at Taser, explains that the company’s search for innovation keeps his R&D staff on its toes. "Our engineers are always seeking to improve our existing products or come up with new ones. That means that a steady stream of prototype work, as well as requests for new tooling and fixtures, comes to our department."
As with all prototype work, whether the request originates in-house or from an outside customer, quick response is essential. This is one of the areas in which CAMWorks has proven itself essential for Cerovic and his team. First, though, some background.
"Before we purchased CAM software we investigated the leaders in the field and determined that CAMWorks was the best for us. It’s easier to use because it is integrated in SolidWorks," explains Research Assistant Dubravko Zekanovic. "That was the initial main selling point." Like many other firms, Taser International uses the popular SolidWorks features-based design software, and the fact that CAMWorks integrates seamlessly with SolidWorks yields a number of benefits. It allows, for instance, the use of a single file for a company’s CAD and CAM systems. This eliminates time-consuming file transfers.
"I used to have to get out of SolidWorks and open different software to write our NC files. That was a waste of valuable time. CAMWorks put an end to that, so that was the main reason that I wanted the software. In R&D we do a lot of different things every day, so setups take a long time and when you have to use two softwares just to get a part programmed, that’s just too much delay. With CAMWorks, we can do so much more," says Zekanovic.
Research Assistant Aleksandar Petrovic, who also works in Taser’s R&D department, agrees. "For me the advantage of SolidWorks integration is most obvious when you need to do a quick contour or a pocket, or when you need to create a brief sketch. With its SolidWorks integration, this is easy to do. With CAMWorks, you change the part and it automatically changes the toolpaths."
This associative machining is another benefit that is facilitated by CAMWorks’ tight integration with the SolidWorks environment. As a result, a revision to a part design updates the SolidWorks solid model as well as the CAMWorks file, allowing CAMWorks to automatically generate the required new toolpaths, the tool list and, if necessary, fixture modifications as well. This has resulted in major time savings for the Taser R&D department on the frequent design revisions it is asked to machine.
CAMWorks Automatic Feature Recognition (AFR) identifies the areas to be machined, and then uses its proprietary Technology Database (TechDB) to automatically generate those toolpaths. AFR also generates automatic programming of families of parts, along with similar features on new parts, as well as the ability to incorporate manufacturing information directly into the solid model. This not only eliminates most of the time-consuming CAM system rework due to design updates, but also speeds the transition from design to finished part on new projects.
Knowledge-based attributes like AFR have the potential to cut hours off the time it takes to move from design to finished part through its ability to automatically identify and define prismatic machinable features. Tight integration with SolidWorks geometry ensures that toolpaths generated produce machined parts that are the same as the part that is modeled—a real boost to accuracy and precision.
Accuracy is also enhanced by the software’s built-in simulation, allowing users to run their machining programs and verify toolpaths right on the screen, not in sometimes expensive and always time-consuming test cuts. This is a plus on the tooling side as well, as users can, if they wish, actually draw the optimal tool that they need for the job if it’s not already available in the CAMWorks tool library. Once drawn, that tool can be used in the simulation.
The Taser R&D department has been using CAMWorks for six years now. They purchased the software at roughly the same time they purchased a Hurco VM-1 CNC machining center. The combination dramatically impacted the department’s productivity.
"I would say it increased our productivity by 300%," declares Project Leader Milan Cerovic. That’s because it allowed the department to turn work around much more quickly than in the past, and bring in-house some work that had formerly been outsourced. But despite the department’s substantial and successful history with CAMWorks, they are still capable of being surprised by the software.
Case in point: VoluMill. Taser has upgraded to the 2012 edition of CAMWorks and VoluMill is an optional, fully integrated milling toolpath engine within CAMWorks for 2.5-axis and three-axis roughing operations. "I have been really impressed with VoluMill," notes Zekanovic. "It has saved us time, saved us wear and tear on our tools, and saved us money." VoluMill can dramatically enhance machining efficiency, particularly when dealing with complex 3-D shapes, as its algorithms result in more intelligent toolpaths to machine pockets, slots, and arbitrary shapes. VoluMill is well suited for machining soft as well as hard materials that are hard to chip, such as titanium, nickel-based alloys, or stainless steel. The result is increased efficiency and utilization of machines, tools, labor and materials.
VoluMill is what is known as an ultra-high performance toolpath (UHPT) software. It uses high-speed continuous tangent motion rather than sharp, interrupted movements. It plans the toolpath based on abilities designed into the machine and cutting tools. By taking advantage of the capabilities of modern machining hardware and avoiding sharp directional changes, it generates toolpaths that assure the machines and cutting tools are used at peak efficiency given the conditions of the application.
Because there are no abrupt changes in direction or to the volume of material encountered, the load on the cutting tools and spindle never exceeds user-programmed limits. Consequently, machines run smoothly and tools run cooler, even at much higher speeds and feeds, extending tool and machine life. VoluMill easily cuts pockets, steps, slots, channels and other shapes, and can handle an unlimited number of material and part boundaries and islands. It can be used with any cutting style and material, including the hardest metals.
This ability to generate optimal roughing paths with maximum material removal rates has reduced cycle times, in some cases by up to 80% and increased cutting tool life, in some instances by up to 500%. Advantages like these, coupled with the types of efficiencies they had already been experiencing through CAMWorks, have proved to be a significant productivity enhancement for Taser. ME
For more information on CAMWorks/Geometric Technologies, go to www.camworks.com, or phone 480-367-0132.
Brings Work In-House
Burndy Products (Littleton, NH) manufactures a wide array of electrical products for the commercial, residential, specialty, and utility markets with products used by the electrical contracting and electric utility industry. Products include electrical connectors, grounding devices, and application tooling for crimping connectors or cutting cable. Markets include data centers, oil and gas, power generation, renewable energy, substation and transmission and telecommunications applications.
The company’s newest products include dual-rated multiple tap connectors, calibrated micro-adjustable torque wrenches, 18-V lithium ion batteries, rotary crimp tool pedestal ground floor connectors, full cycle hand tools, and higher-performance tools. Brand names include Implo Connectors, Grounding Super Store, the Smart Cart Wire Caddy products, and the Wedge Tap connector system.
Principal products manufactured at its 160,000 ft2 (14,864-m2) Littleton, NH, plant divide about evenly between manufacturing connectors and application tooling. Recently, Burndy acquired an IG 280 SD industrial rotary surface grinder from DCM Technology (Winona, MN) for grinding components for its application tooling. Dave Adams, operations manager, explains that the rotary grinder was purchased for precision machining of applications tooling, a line of mechanical tools that resemble pruning shears. There are two lines, the ND 6 and ND 7, depending on the type of handle.
"The tools are mechanical crimping devices with a set of jaws that are activated by a long set of handles. We’re grinding a forged jaw flat to within a couple of thou," says Adams. "After precision grinding, the jaws are then taken to a Mazak CNC machining center where crimping grooves and pivot holes are machined. After machining, the jaws are either nickel-plated or blackened, and then assembled into the tools."
Burndy had discontinued machining the jaws on an old Blanchard grinder, which had been sold off. When the market turned down after the recession, the company sought a way to reduce the cost of outsourcing the components. Adams explains: "The DCM IG 280 SD industrial rotary grinder was identified as a cost-effective way to bring the parts back in-house by making a capital investment at a particularly challenging time. The rotary surface grinder gave us the advantage of its self-contained process automation, and the DCM servo drive control provides feeds and speeds and monitors the grinding process. With it, we can save grinding parameters and recall grinding for production runs or for use in a manual mode for lab work or prototyping.
"Unlike the Blanchard, which was a large machine, the DCM grinder is compact with the ability to machine a number of different parts that we have. We grind the jaws in lots of 24, as well as some other smaller forged parts, some links, and also cutter blades. We brought it in for the jaws, but we knew that there would be other applications. We had gotten away from our wet grinders, where the cost was fairly high. With the DCM, we can get parts done faster and more parts at a time," Adams explains.
The 20-hp (15-kW) grinding spindle of the DCM IG 280 SD features variable speed and automatic demag cycles. An integral air mist collection system draws particulates and mist away from the work area, for machine cleanliness and work environment. The DCM has flood coolant to remove a lot of material swarf, keeping the part cool and extending grinding wheel life.
"We played around a little bit with the wheel hardnesses that we needed and pressure to maximize the life of the stone and lower cycle time. We’ve run it for about a year and a half and have more control over the process. We’ve reduced our fallout rate, and our scrap rate has gone down because of our ability to control the process with CNC. We’re doing 5000 tools a year, that’s 10,000–12,000 jaws a year and have shortened turnaround time from two to three weeks from an outside vendor down to a matter of hours doing it internally," Adams concludes. ME
For more information DCM Tech Inc., go to www.dcm-tech.com, or telephone 800-533-5339.
Automating the machining process is one certain way to achieve efficiency in manufacturing. Another way manufacturers are effectively meeting the growing demand for highly productive and accurate machining is through the incorporation of tool management systems. Treske Precision Machining Inc. (Sherwood, OR) not only implemented such a system, but they created it themselves. The manufacturer of high-tech semiconductor, infrared, and laser products developed a customized data management system to optimize the use of machine technology.
Established in 1977, Treske employs a staff of 125 in an 80,000 ft2 (7432 m2) facility. The company’s primary focus is CNC milling, but it also provides CNC turning, assembly, and welded fabrication services. The shop houses approximately 50 pieces of CNC machining equipment. Over the past six years, Treske has concentrated on developing their machining cell environment. The manufacturer’s primary production center is a 400-mm Makino a51 horizontal machining cell with five machines and 66 pallets which runs 24/7.
One big challenge Treske faced was utilizing this machining cell in a low-volume, high-mix environment. "In our research we found a lot of shops using machining cells in a high-volume, low-mix environment and knew that was not our market," states Theo Treske, president. "Our customers are low-volume, high-mix and we have excelled in supporting them by optimizing machine technology to reduce setup and changeover time." Treske’s Makino Cell has more than 2000 active jobs loaded into the system, which is 10 times what most manufacturers run, according to the company. At any given time, Treske runs 75–100 jobs simultaneously through the five machines in the cell. "We work to achieve efficiency not just through automation of the machining process, but also by developing data management systems to effectively communicate information," Treske continues. "The latest machine technology is only fully utilized with a complete support system behind it. This includes tooling, quality monitoring, and job management."
With their data-management system and the reliability of the toolholders and machines, Treske has seen some dramatic improvements. "When we started we were getting 16 hours of cut time per day. Since then, we have been able to increase to an average of 23 hours per day, keeping everything running smoothly with minimal tooling or equipment problems," Treske says.
For quality monitoring, Treske’s data-management system is equipped with a proprietary SPC tracking systems developed by Treske for continuous improvement of parts in production. It is a Web-based system that is continuously monitored by their production and quality staffs. This tracking system analyzes real-time inspection data and communicates an interactive list of all features on actively running jobs. It calculates the Cpk value of each feature and lists them in ascending order, therefore directing everyone’s focus to the features that need priority attention. It also incorporates Nelson Rules tracking and alerts personnel when there is a violation. All features with Cpk below 1.33, or Nelson Rules violations are required to be addressed with Corrective Actions, which are maintained in the database.
The system graphs the measured dimensions and creates X Bar, R Chart, and Capability Histograms to track and analyze the data. Scheduling, material and fixture management, and priorities are all incorporated into this interactive system. The combination of these systems and others allows the floor to be managed in a largely paperless process that maximizes both control of the workflow and flexibility.
An internal tool management system manages what tools are in a system at any given time. As jobs are changed, it indicates which tools need to be taken out or loaded into a machine. "With over 2500 tools it takes a robust, integrated system to just keep them organized, a system that was not available anywhere," says Treske. "That is why we developed our own proprietary system."
For consistency and easier tool management, Treske opted to focus on one family of toolholders to support the machining cell. "There are enough variables to control, you can’t have tooling become another one," states Treske. "We recognized using multiple lines of toolholders adds complexity to the management of the system."
Six years ago, Treske went to IMTS in Chicago and researched every possible toolholder option. They decided on Lyndex-Nikken toolholders for a number of reasons. "Throughout our research we looked at a lot of different toolholding systems," explains Mike Orlander, Treske operations manager. "We decided to go with the Lyndex-Nikken system because it offers the flexibility and reliability we need. The holders have delivered the consistency and accuracy required across our challenging range of projects."
The wide range of toolholding that Lyndex-Nikken offers allows Treske to maintain consistency within the brand, while covering their diverse needs. "Not many tooling suppliers could support the broad spectrum of holders we require. And with Lyndex-Nikken, reliability has never been a factor," Treske comments. Out of the over 2500 individual tools currently at Treske, 80% are loaded in Lyndex-Nikken holders. "Lyndex makes it easy to manage the tools that we have on the floor because their quality of design and workmanship yield consistent performance with no breakdowns," Treske says. The flexibility of the Lyndex-Nikken offering enabled Treske to use the same tools across multiple parts.
The majority of the Lyndex-Nikken toolholders used at Treske are from the Advanced Line, including balanceable ER collet chucks, SK collet chucks, MMC/Insider collet chucks, and shrink-fit holders. "All of the tools in the cell are used on multiple jobs. To manage offsets between these multiple jobs requires accuracy," says Olander. "Tool changing and maintenance are straightforward and don’t require special tools. Most of the toolholders are a collet system so they don't require something to load the tools." Another factor that influenced Treske’s decision was that the Lyndex-Nikken line requires minimal training. ME
For more information on Lyndex-Nikken Inc., go to www.lyndexnikken.com, or phone 847-367-4800; for information on Treske Precision Machining, go to www.treske.com, or phone 503-625-2821.
Fixturing Keys Cast
mproved fixturing in the form of hydraulic workholding is credited with doubling output and improving accuracy in machining cast parts at Southland CNC (Cornelia, GA). Southland is a Tier Two supplier to the automotive industry, providing machined aluminum sand-cast components to all three American and the six largest foreign auto manufacturers. The company, which was started 19 years ago in President/Owner Keith Armour’s garage on a single machine, has now grown to 30 employees using 21 high-capacity machining centers.
Southland machines a variety of parts that includes high-volume production runs, as well as relatively low-volume production runs. Southland uses dedicated hydraulic clamping fixtures on Okuma Howa VMCs for its high-volume production runs, because these fixtures greatly reduce production time, which makes the fixturing highly cost-effective. The dedicated hydraulic fixtures also provide clamping pressure that is consistent and repeatable, which improves machining accuracy.
According to Keith Armour, the typical tolerances are held to 20-µm true position, with critical dimensions to ±6 µm, which he credits largely to the hydraulic fixturing supplied by Southland’s longtime supplier, Advanced Machine & Engineering (AME; Rockford, IL). Because low-volume production runs don’t justify dedicated fixturing, Southland uses manual fixturing for its adaptability and lower cost of acquisition, when appropriate.
Currently, Southland has four HMCs that use hydraulic tombstone fixturing, and three VMCs that use hydraulic tombstone fixturing, all designed and built by AME. These fixtures are dedicated to high-volume production of single parts or single families of parts.
Southland chose AME to provide its first tombstone hydraulic fixture because the fixturing solution was competitively priced and specifically designed by AME Engineering to fit Southland’s production needs. Delivery, which was very important to Southland’s production scheduling, was significantly better than any other designer/supplier, according to Armour. The first AME fixture specifically replaced the customer-supplied fixturing Southland had been using, which Southland determined wasn’t providing the efficiency needed to meet cost and schedule goals for the high-volume production run.
The advantages provided by the AME-designed fixture included reduced load/unload time, reduced cycle time, reduced scrap rates, and error-free loading. The initial application of the fixture reduced Southland’s cycle time by over 50%, which allowed Southland to meet the high-production volume without additional machines. On one bearing plate for a supercharger assembly, according to Keith Armour, production has gone from 50 units to 110 units per day with the same superior tolerances and a 1.67 Cpk, critical to the Six Sigma conformity for its major automotive customers.
The fixture, which provides automatic clamp and release, is designed with locating dowels to assure error-free handling. Each component to be machined is handled only twice, once as it is loaded into the fixture, and a second time as it is unloaded. Because the fixture is a windowed fixture, the component is completely machined on all four sides without additional handling. On the vertical machining centers typically, a second loading pallet is used to mount workpieces while another fixture is running in the machine.This further enhances Southland’s throughput.
Keith Armour says that the AME-produced fixturing has been very reliable. One fixture has been in operation 20 hours a day, five days a week for more than seven years without a single problem. Because of this reliability, and because of the cooperation and innovation AME has provided, Southland added a second fixture used on the vertical machining centers, plus a fixture dedicated to horizontal machines.
"The fixture configurations we designed for Southland include cast tombstones as well as welded tombstones. Depending on the intended use for the fixtures, they were provided with external surface-mounted hydraulics as well as internally cored hydraulics," according to Alvin Goellner, AME fixturing group manager.
On one particular part, a bearing plate for a supercharger, the part is aluminum sand-cast, measures 8 × 4 × 11/2" (203 × 101 × 38 mm). A two-operation part per side, the workpieces are loaded in less than 20 minutes on a second fixture, using the secondary pallet on the VMC. Southland produces approximately 30,000 of this part annually for a Tier One supplier to Jaguar, BMW, and Mercedes.
"The fixture was designed specifically for this part, though it’s flexible enough to allow us to use it for other jobs," Armour explains. "AME had a very short turnaround time, plus their knowledge of workholding and the components they selected were all first-rate. We have experienced zero downtime because of the fixturing they supplied us for this particular part. Although we tweak the rest pads for enhanced accuracy, that’s normal with the machining centers we use."
Armour says that the design and development work was done via CAD drawings and the completion of the entire project was done on schedule and at the quoted price. "When we began to go from 50 parts per day to 110 or better, with absolutely no loss of accuracy and finish quality, we knew we’d made a wise choice," says Armour. All accuracies are checked on the in-house CMM at Southland for verification. ME
For more information on Advanced Machine & Engineering, go to www.ame.com, or phone 815-962-6076.
This article was first published in the September 2012 edition of Manufacturing Engineering magazine. Click here for PDF.