PDM comes to the OEM
Newton, MA—In recent years, product data management (PDM) has grown at an amazing rate. Many vendors are comparing the current PDM market to the budding CAD arena of the early '80s. In fact, Bill Mason, president of Adra Systems (Chelmsford, MA), is among the many who believe that the PDM industry will grow at a faster rate, overall, than CAD. Already, 1994 saw a 36% growth in PDM, according to CIMdata Inc., anAnn Arbor, MI-based consulting firm.
Testimony to the increasing interest in PDM is the flood of products hitting the market. Among the recent offerings: Matrix from Adra Systems Inc., OptegraTM from Computervision (Bedford, MA), CMS from Workgroup Technologies (Lexington, MA), ProductManagerTM from IBM (Charlotte, NC), Control Data's (Arden Hills, MN) Metaphase Series 2, and DM2 from Intergraph (Huntsville, AL). Even long-time CAD giant Autodesk (Sausalito, CA) has ventured into the PDM market with the introduction of its Workcenter product.
Signs of the times. There are now specialized conferences aimed at helping companies address their PDM needs. Perhaps the most widely-known is the EDMS/PDM User Forum series developed by Cincinnati-based Kalthoff International. The series is geared toward helping companies shorten the buying cycle for advanced engineering documentand productdata management systems.
Begun in September 1990, the first EDMS/PDM Forum drew a total of 156 attendees, including 22 vendor-participants. By 1994, demand justified two Forums per year in the U.S., while 1995 marked the launch of EDMS Europe. The 1994 Forums boasted a combined attendance of 1,600--a ten-fold increase in just four years! 1995 saw continued improvement as the Forums welcomed approximately 2,000 attendees. Meanwhile vendor participation grew by a factor of four.
Over the past decade, CAD has streamlined the design process in many ways. Now, companies need a way to control the data that CAD and analysis tools are putting at engineers' disposal. Integrating and sharing data with other engineers and departments throughout the company has become a necessity, and companies are lining up to take advantage of what PDM has to offer.
Better communication. When various departments at the Toro Co., Bloomington, MN, required information on a specific project, they turned to engineering to deliver the data. To eliminate this time-consuming process, Toro created a repository of part information so outside departments could access needed information without relying on engineering.
The company implemented a system centered around Optegra Vault from Computervision. The "vault" consists of two basic areas for information storage: the "released for production" area with master files for projects currently in production; and the "published" area, with information on parts not yet in production that require some type of communication from other internal departments.
Currently, Toro saves all CAD parts and about 1/3 to 1/2 of the company's legacy data in the vaults, with the remaining legacy data soon to be scanned in.
With the new system in place, outside departments no longer need to ask engineering for help. And the possibility for errors is minimized--having direct access to the data ensures these departments will get the most up-to-date product information. Says Ron Cozad, senior principal systems engineer at Toro, "It's amazing how effectively we've improved communications with other departments. The system has improved the reliability & responsiveness of our concurrent engineering work."
Improved processes. The Manufacturing Systems Integration Div. (MSID) of the National Institute of Standards and Technology (NIST), Gaithersburg, MD, is using PDM as a major component of its Computer-Aided Manufacturing Engineering (CAME) project. CAME's Manufacturing Engineering Toolkit (METK) project is sponsored by the US Navy Manufacturing Technology Program. The goals of the project: to integrate a suite of commercial, off-the-shelf manufacturing tools for planning part production, validating manufacturing data, and simulating part quality and process performance before a job is released to the shop floor.
Project participants include manufacturers, software vendors, government agencies, and universities. The METK project is centered around the Matrix PDM system from Adra Systems Inc. Matrix is used to launch a number of applications, including a CAD program, a process planning system, and simulation software. Once a product model is developed, information is transferred to the generative process planning system, where a machining process plan is defined. This process plan is then input into a simulation program to detect potential collisions and near-miss conditions between the machine, tooling, fixtures, and the workpiece.
Data involved in the planning process range from machine tool models, tooling lists, fixtures, set-up sheets, operation description sheets, and NC programs, to drawings, inspection plans, and lot sizes. Matrix provides centralized management and control of this information.
When planning tasks are completed, engineers check the resulting data into the Matrix database, making the information available to process planners, tool designers, NC programmers, reviewers, and others in the company. Matrix provides select individuals with immediate access to this manufacturing information, which must be reviewed, commented on, and approved before being released to production.
"The system eliminates duplicate entries of data and significantly reduces the chances of errors," says Swee Leong, manufacturing engineer in the Manufacturing Systems Engineering Group of MSID.
Worldwide sharing. Ericsson, a global communications manufacturer based in Stockholm, Sweden, is developing a worldwide database network centered around Metaphase 2.0 from Control Data. Currently, Ericsson companies around the globe use different PDM systems, many of which are not accessible to outsiders. By implementing a global system for archiving various types of documents, Ericsson hopes to improve communication between its 80,000 employees worldwide.
The ultimate goal for the new system is to improve efficiency by enabling Ericsson to take advantage of the fact that its employees are in several different time zones. Using the relay principle, the company aims to put people to work around the clock.
For example, when an engineer in Stockholm has completed his day's work, he turns his project over to an engineer beginning her day in Dallas. When she goes home, another engineer in Melbourne could continue the work on that same project. When the engineer in Stockholm arrives at work the next day, he will have a completed project on his desk.
The system, called the Project Data Library (PDL), will consist of Metaphase2.0 enhanced with an Ericsson layer around it. ThePDL will provide the complete functionality of Metaphase, communicate with Ericsson's systems for storing released information,and be integrated with commonly used tools, says Jan Johansson, executive project leader at EIT, Ericsson's Core Unit.
--Deana Colucci, New Products Editor
Plastics, software help slash meter part count
Erie, PA—New materials and solid modeling software helped Smith Meter Inc. cut the parts count on a petroleum meter from more than 40 to about 15. "This increases reliability and performance," says Chuck Lazan, manager of engineering services at Smith, a subsidiary of FMC.
Engineers now use one-piece molded blades made of polyketone, taking the place of casting, ball bearings, and pins. An electronic pickup replaces a mechanical gear train, further cutting the PRIME 4 meter's part count. The direct-pulse output is much less expensive than a traditional pulse transmitter, Smith engineers say. Other features: recessed rotor ends, super-hardened cam, and horizontal rotor.
The positive displacement meter is Smith's first product designed completely with CATIA 3-D software, which was developed by Dassault Systems and is now sold by IBM. "CATIA made real-life simulation possible in the early stages of development, so that we could get input from the marketplace and make appropriate adjustments," Lazan explains.
CAE Engineer Ron Trapp said the 3-D software helped visualize proposed designs before they were sent out for patterns to be made. In some cases, Smith sent out color print-outs of the design to outside vendors; for plastic blades, electronic files were used to generate molds. The company estimates that 3-D models cut time needed for outside pattern making by 25 to 30 percent.
Yacht rides the waves on a wing
Boston—It's a sailboat! It's a plane! No, it's a Zephyr from Walker Wingsail Systems, Devon, UK: a 43-foot yacht powered by the wind, diesel engines,or both.
Designer and company presidentJohn Walker created the Zephyr withthe goal of making a stable, easy-to-sail craft that would take advantageof the wind without the complexity and inefficiencies of traditional cloth-sail configurations. Walker combined aviation design experience--including work on the Concorde--with nautical know-how to create the trimaran.
Using such CAD software as MacSurf from Chance & Co., Inc., Essex, CT, Walker engineers designed the monohull to U.S. Coast Guard and other national specifications. The hull is vacuum-molded with epoxy resin from Ciba-Geigy Corp., Hawthorne, NY, reinforced with knitted unidirectional glass and carbon fibers.
The wing assembly consists of a large leading surface, an air-directing slat, and a separate tail. The "sails," which are computer-controlled using hydraulics and bearings from SKF USA, Inc., Bethlehem, PA, rest on a1m-diameter, freely rotating main ring bearing made by INA Bearing Co., Inc., Fort Mill, SC.
"The wings and tail are completely free to trim the wind, just like a rather large weathervane," explains Walker. "The freely trimming system automatically cancels out the effects of seaway motion, maintaining a precise and constant angle of attack so that the drive is steady."
When the wind dies, the boat can be powered by a pair of diesel engines from Lister Petter Inc., Olathe, KS. The Zephyr's instruments and domestic appliances are powered by solar panels from Solarex, Frederick, MD, which also recharge the engine's batteries.
A computer control system provides automatic tacking and gybing and full-time electronic governing to prevent overpowering and capsize.
Walker and his wife, Jean, recently completed a trans-Atlantic journey in the Zephyr Sea Change.
— Andrea Baker, Associate Editor
Prototyping moves to the desktop
Valencia, CA--The industry's leading rapid-prototyping company has developed a new technology it says will make creating models from CAD data as easy as making a print-out.
Called Multi-Jet Modeling (MJM), the process is aimed at supplementing 3D Systems Corp.'s existing stereolithography systems. MJM, an inkjet technology, will sacrifice some accuracy compared to stereolithography, a 3D spokesman says, but will offer higher speed and ease of use.
Any engineer will be able to send out a design to be modeled, the same way CAD data is sent off to a plotter. The goal: Catch errors at the beginning of the design process, when they are easiest and least expensive to fix.
MJM uses a "print" head of 96 jets, each activated by an electrical signal, arranged in a linear array. The multi-jet head moves back and forth on an X axis like a printer, building models in successive layers using a special thermopolymer material.
3D Systems has sent evaluation units using MJM technology to several beta customers. Commercial systems based on the process will be available sometime this year; prices have not been set.
PCMCIA diagnostic card simplifies design
San Jose, CA—Developing or troubleshooting PC-MCIA card (PC Card) hardware or software used to require expensive test equipment, such as a logic analyzer, and detailed knowledge of the electrical interface signals. Now there's a "quick and dirty" way.
Using the new PC ReportCard™ in conjunction with the PC ExtenderCard™, both from Accurite Technologies, Inc., engineers can see PC Card I/O and memory access cycles displayed on a series of LEDs. And they don't have to figure out what constitutes a memory cycle and set the logic analyzer to capture those cycles.
PC ReportCard is a passive device that monitors PCMCIA bus activity without using special software. You can connect the card's external trigger signal to an oscilloscope or logic analyzer to capture detailed information about the timing cycles.
Consultant Tom Newman of Mission Peak Designs uses the two products to debug PC-MCIA hardware and software. "The PC ReportCard decodes memory and I/O cycles, and shows you on the LEDs what's happening in a general sense. You can get more specific information from a logic analyzer."
"If you know what you're looking for," continues Newman, "the logic analyzer is the way to go. But if you want to tell at a glance if a card is being accessed and configured properly, try the PC ReportCard."
The companion product, the PC ExtenderCard, is a 4-layer pc board with extensive grounding to minimize noise and maximize signal integrity.
One feature Newman especially likes is the push buttons that simulate the removal and reinsertion of a PC Card without wear and tear on the card's sockets and pins. A second socket provides direct access to all bus signals of the computer's PC Card slot, accepting adapter cards for logic analyzers or the PC ReportCard.
The PC ReportCard andPC ExtenderCard cost $229 each, or $425 if purchased together.
Work from noon 'til midnight with zinc-air battery for notebook
Smyrna, GA—Traveling workaholics, rejoice! If you use a Hewlett-Packard OmniBook 600, you can buy a second, long-running external battery that will keep you computing for up to 12 continuous hours.
The PowerSlice LX battery from AER Energy uses zinc-air technology and includes a hand-rest and a mouse table. It fits under the computer and still allows access to all computer drives and ports. A built-in fuel gage lets users know how much charge is left in the battery. Users recharge the battery via the computer's ac adapter.
AER Energy's zinc-air battery is an "air-breathing" battery that relies on oxygen from the air to support chemical reactions that generate electricity. It has the highest energy density by weight of any portable-computer battery technology currently on the market, say company officials.
Also, unlike some other types of batteries, rechargeable zinc-air units develop no memory effect. Users can recharge it whenever it is convenient, even though the battery may not have been fully discharged.
The battery is available now for $399. It's charged and ready to use out of the box.
Processor aids scramble to design 900-MHz communicators
Berkeley Heights, NJ—Some major players recently plunked down $8billion for the right to offer wireless personal communication services (PCS)in the U.S. Now, the race is on to develop the portable devices that will succeed in this 900-MHz narrowband arena. One of the first companies to offer a processorfor such products: AT&T Microelectronics.
The POMPTM DSP1615 is a 16-bit, fixed-point digital signal processor for two-way PCS messaging devices. In fact, Motorola has already adopted the processor for Tenor, which acts like a portable answering machine. In other PCS applications, the programmable DSP can implement two-way simple and enhanced messaging--no matter which narrowband PCS protocols the designer chooses.
Based on AT&T's DSP-1600 core, the DSP1615 includes only those features necessary for messaging: codec, memory, clock, andcontroller peripherals. The A/D converter runs at 38.4 kilosamples/sec with a variable-rate D/A converter; on-chip memory comprises 48 kbytes of ROM and 4 kbytes of static RAM.
Other chip features geared for portable devices include low-voltage operation, low power consumption, power management, and four I/O ports. AT&T also offers system and application support through various libraries to provide generic programming examples and a set of routines specific to wireless paging protocols.
An IEEE 1149.1 test port provides access to the on-chip hardware-development-system circuits, allowing designers to completely control and debug systems via the complete range of DSP1600 tools. Both MS-DOS and UNIX development systems are currently available. Processor prices start at $16 each in 100,000 quantities.
Sun jumps back into workstation race
Menlo Park, CA—In what company officials called their most significant technology announcement since the SPARCstation, Sun Microsystems has unveiled a new system design that puts the workstation manufacturer squarely back in the desktop technology race.
"This is far more than simply dropping a fast microprocessor into a standard computer," said Ed Zander, president of Sun Microsystems Computer Corp. At the heart of the new design: a complete overhaul of the way data flows through the system.
Sun engineers replaced the conventional desktop bus with a switch-based interconnect--technology more commonly seen in high-end mainframe- and supercomputer-class machines. They say this Ultra Port Architecture operates up to 1.3G per second, at least double the speed of most competing desktop computers.
Other features of Sun's UltraComputing design: graphics and multi-media technology built into the microprocessor; and "3-D RAM," co-developed with Mitsubishi, that allows up to a ten-fold increase in high-end graphics performance. The 3-D RAM frame-buffer memory architecture combines features from video, dynamic, and static RAM design. A 100 Mbit/second Fast-Ethernet controller is built in.
The first workstations announced using the new architecture are built around UltraSPARC 64-bit RISC chips, which can process up to 10 pieces of data in a single clock "tick."
Industry watchers have said for several years now that Sun was lagging behind other major players in developing hot new workstation technology. Sun officials, though, say the new Sun Ultra 2 workstations are now the fastest in the industry.
"They're going to stay in the fight," says Norm Weizer, a consultant with A.T. Kearney in Dallas. "This brings them up at least to par, maybe a little ahead. Then we should see more leapfrogging."
"For the first time in two-and-a-half years, people are waiting in line to use Sun's systems," says John Zepper at Sandia National Laboratories, an early beta site for the new machines.
Prices for Ultra 1 and 2 systems range from $16,495 to $59,995. The entry-level Ultra 1 Model 140 features 143-MHz CPU, 32M main memory, 1G hard disk, graphics accelerator, and 17-in monitor. The high-end Ultra 2 Creator 3D Model 2200, an expandable multi-processor system with two 200-MHz CPUs, comes with 256M memory, 4G hard disk, 20-inch color display, and Creator3D graphics. Sun says the system achieves 332 SPECint92 and 505 SPECfp92 performance, which it calls the fastest numbers in the industry. More information is available at http://www.sun.com.
Polymer box protects underground cables against damage
Glendale, CA—Local newspapers are full of stories about construction equipment accidentally pulling up underground fiber-optic cables and cutting off customer services. A polyurethane box designed by Bayer's Polymers Div., Pittsburgh, PA, for Cott Manufacturing could eliminate such mishaps.
The 60- × 30- × 30-inch box stores up to 160 feet of extra cable. When the cable is accidentally pulled by a backhoe or other equipment, the extra cable releases from a special rack. The Cott-Box® box, buried two feet below the surface, has to withstand a load of up to 20,000 lbs. This equals the weight from one set of wheels on a semi-trailer with a full load. In addition, the material used for the box had to offer rigidity, a high flexural modulus, durability, chemical resistance, good impact resistance, and minimal water absorption.
Bayer technicians came up with a design that features a reinforced 3/8-inch-thick lid. The side and bottom panels measure 1/4-inch thick. Both were constructed using Bayer's Bayflex® XGT-100 elastomeric polyurethane RIM system.
The internal rack measures 36 × 2 × 1 inches. It consists of Bayer's Desmopan® KU 2-8651 thermoplastic polyurethane. The rack bolts to the side walls of the box, and features rungs shaped like waves, around which the slack cable is looped and instantly releases when pulled.
Traditionally, the protective boxes were made using a fiberglass and polymer concrete hybrid. This proved to be a very labor-intensive, "handmade" product to build. It also resulted in low quality consistency. And the boxes weighed almost 500 lbs.
With the new design, cycle times for molding the side and bottom panels average three minutes and five minutes for the lid. The modular components are assembled with bolts, with the finished weight totaling only 210 lbs.
"The modular design results in a box that can be carried and installed by hand," says Cott Manufacturing President Jeff Thomas. "You also can transport the panels flat and then assemble them on site."
The box will get its first major use on a new 17,000-mile, fiber-optic cable system now under construction in Mexico.
Composite keeps all-terrain vehicle competitive
Minneapolis—When all-terrain vehicle (ATV) manufacturer Polaris Industries Inc. redesigned its top-of-the-line Xplorer model, key structural components took on a sleek, new look.
The update included structural footwheels, racks, and bumpers that just couldn't be produced economically in steel, the traditional material. Polaris engineers considered injection-molded plastic suitable for fascias, but not structural parts--until they discovered a long-fiber-reinforced thermoplastic.
"We wanted a new look, an aesthetic upgrade. We also wanted to add new functional features, while improving product durability," says Matt Parks, Polaris product manager.
The design teams gave Parks the styling he sought. New functional features included such items as lugs in the footwells to keep the footfrom sliding forward when going down a hill, a rack that could take an extender soyou could pile on a bale ofhay, rack pockets that would accept a bungee cord, and more. Making it happen proved harder.
"We have a long history in dealing with metal for our structural parts," says Mitchell Johnson, ATV research and development manager. "If you can bend it, cut it, and weld it, we are comfortable with it. Our new design, however, did not easily permit the useof metal."
Polaris had tried injection-molding short-glass engineering plastics before, but they didn't provide the performance needed at the required costs. The engineers were well along on the development of a bulk-molding compound (BMC) solution, when the company's molder, KenTech, suggested injection-molding a long-glass, fiber-reinforced plastic material. The recommended material: Celstran® from Polymer Composites, Inc. (PCI), Winona, MN. What most caught the attention of the engineers was Celstran's ability to mold-in color.
Johnson also learned from the molder that the material could deliver the rugged performance Polaris demandedof steel, plus corrosion resistance, and that it couldeconomically achieve the complex, three-dimensional contours and functionality required.
Based on their performance assessment and cost targets, KenTech and PCI found that the Celstran polypropylene parts passed the test.
Brake cuts exercise-equipment cost
Huntersville, NC—A magnetorheological (MR) fluid brake from Lord Corp., Erie, PA, is quietly entering home gyms in new aerobic exercise equipment designed by Nautilus.
To deliver an effective design at home-gym prices for their new recumbent bike and stair-climber, Nautilus engineers had to find ways to cut cost. "One area we looked at was our brake system, another was electronics," saysGregory Webb, Nautilus Vice President of Engineering.
Nautilus engineers teamed with Lord to replace conventional eddy-current brakes with Lord's RheoneticTM MR fluid rotary brake. Though effective, the cost of the previous eddy-current brake design put the equipment price beyond the realm of consumers, says Webb.
"MR fluids provide 20-50 times the strength of conventional electrorheological fluids, insensitivity to contaminants and temperature extremes, and the ability to be controlled by low-voltage electronics," explains David Carlson, senior staff scientist at Lord.
By comparison, eddy-current brakes have to run at high voltages, and they require quite a few coils, so their cost is higher, adds Webb. "The advantage ofthe MR brake is that it's very compact, and it can run on 12V. The brake is less expensive, and we can use a much less expensive power supply," he adds. The switch to a 12V system allowed engineers to replace a power supply thattypically cost $50 with a smaller, $5-6 wall pack.
"Also, the power going to the Rheonetic brake is from a pulse-width modulated circuit, and since it's only 12V we have very small amounts of heat to dissipate from the output transistor," says Webb. "That allowed us to eliminate a heat sink on the control circuit."
The same custom brake is used on both pieces of equipment and measures 1.5-inch thick and 35/8 inch in diameter. The brake spins at about 900 rpm. In the bike application it dissipates about 500W maximum; in the stepper, 750W, says Webb. "With the new brake, we don't have noise and we don't have shock. It's very quiet and smooth."
Crystal polymer hurdles insulation barrier
Wilmington, DE— Miniaturization and downsizing increase heat, creating the need for insulation systems that can better handle higher operating temperatures. Electrical manufacturers now have that capability in a liquid crystal polymer (LCP) for ground insulation.
Making this possible: a recent announcement that Underwriters Laboratories has awarded provisional recognition to a Class R (220C) Electrical Insulation System using ZeniteTM LCP. The system, designated L500, establishes a minimum wall thickness of 32 mil (0.81 mm).
"This is the first UL 1446 insulation system allowing the use of an injection-moldable thermoplastic beyond Class N (200C)," says John Solenberger, E/E industry team leader for DuPont Engineering Polymers.
The new listing allows electrical manufacturers to avoid thermosets for molded coil bobbins or other ground insulators in Class R devices. "In choosing Zenite LCP over thermosets, electrical manufacturers and components molders can reduce part costs, improve toughness for automated winding and assembly,and eliminate VOCs (volatile organic compounds) during molding," Solenberger adds. The cost savings derive from fast molding cycles, elimination of deflashing, and use of mold-in assembly features.
Solenberger cites microwave-oven transformers as the most likely candidate for the new Class R system. Near term, the trend to smaller, hotter devices of many kinds should increase the need for such systems.
Bobbin benefits from plastic components, outside design aid
Knoxville, TN—Like most televisions, those made by Phillips Consumer Electronics Corp. (PCEC) use a transformer to step up the 110V household voltage to the 30,000 volts needed to fire the electrons in the TV's cathoderay tube. A key element of the Phillips step-up unit: the Micro-Plus bobbin, around which wire is spun to create the needed magnetic induction.
Each element of the Micro-Plus design presented its own challenges. However, the secondary bobbin's function made it the most demanding element of the unit, according to PCEC Project Engineer Scott Jahns. Developed to accommodate miles of 0.002-inch-diameter varnished wire, it features a barrel-like design with 15 slots, each 0.025-inch in width. Because of the extremely delicate nature of the wire being spun around it, slotted areas had to remain free of any traces of flash, mismatches, or contamination that could cause damage.
To avoid this happening, PCEC teamed with Phillips Plastics Corp.'s Automatic Molding Facility, Menomonie, WI, for the bobbin's design and production. Material concerns in the Micro-Plus program proved critical, since each part had special needs.
For example, the case, which required a resin meeting UL approval, was molded using Rynite® FR7915, a 15% glass-filled polybutylene terepthalate (PBT) resin from DuPont. Conversely, the primary bobbin demanded a certain degree of resistance to heat. For that, the design team turned to Rynite FR530, a polyester resin.
To mold the part of the assembly that would encounter the greatest degree of voltage stress, Phillips and PCEC selected Noryl® SE1GFN2, a glass-filled polyphenyl oxide from GE Plastics, for the secondary bobbin. While the material does provide excellent dielectric strength.
The air gap spacer, used to maintain a uniform gap between a compression-molded powder iron core, comprises the smallest part in the assembly. It, too, presented some tough challenges. Its size--less than 0.20-inch-thick--demanded that a crystalline material be used that could easily flow into such tight confines. Part thickness specifications also proved equally challenging: tolerances to within ±0.001 inch. To meet this need, the team chose DuPont's Delrin® 1700P, an acetal resin.
The Micro-Plus program has proven to be very rewarding, Jahns says, largely because of the tremendous amount of open communication between Phillips and PCEC. "It shows that two companies working together can successfully execute large-volume, highly demanding programs," he concludes.
Powder metallurgy eliminates machining
Indianapolis—In applications from trucks to trimmers, powder metallurgy (P/M) can simplify manufacturing by eliminating secondary machining. In some applications, P/M's near-net-shape capability replaces machining entirely.
For example, a differential case from Metal Powder Components, Coldwater, MI, is a net shape componentthat requires no secondary machining. The P/M design replaces an extensively machined casting that was previously bolted together. The complex, five-level nickel-steel part serves as two halves of an inter-axle differential case used in a heavy-duty tandem axle assembly for Class 8 trucks made by Eaton Corp. Truck Components, Kalamazoo, MI.
The halves are gas metal arc welded together to form the case, which distributes input power between the front and rear tandem axles. The case must withstand significant rotary and thrust forces, including side pinion thrust forces, side pinion/thrust washer rotation, and spider force, say Eaton engineers.
Converting to P/M allowed engineers to reduce the case's cost and size, which lowered the input shaft height and the fifth-wheel height, resulting in lower trailer-bed height and more cargo capacity.
Fewer parts. P/M can also reduce parts count for significant cost savings. Case in point: an integral rotor/flywheel gear used in a high-speed mechanical printer for Printronix, Inc., Irvine, CA.
Engineers at Ceromet, Anaheim, CA, used P/M to design the component, and to combine the flywheel and the magnetic rotor of the drive motor. "This not only reduced the parts count, but also simplified assembly of the motor, resulting in an estimated savings of 90% compared to investment-casting and machining the parts," explains Ceromet Sales ManagerLarry Totzke.
The process achieves precision as well, says Totzke. The tooth form on the 59-tooth rotor is accurate to within one-half of one degree. Ceromet engineers chose a phosphorous magnetic iron material for the part. The powder is compacted to a 7.0 gram/cubic centimeter minimum overall density, with a 7.2 g/cc minimum density in the hub and boss area. The hub and boss have a yield strength of 30,000 psi, while retaining the necessary magnetic properties.
"The only secondary machining operation the part requires is the drill and tap of the side hole," adds Totzke.
Both the rotor/flywheel gear and differential case from Metal Powder Components won design awards at the annual InternationalConference on Powder Metallurgy and Particulate Materials in Seattle.
Teamwork. For a similar project, Ceromet recently teamed with Carbon City Products, St. Marys, PA, to produce a powder metal gear and cam assembly for a dual-action electric hedge trimmer from Poulan/Weed Eater, Shreveport, LA.
The gear and cam combine to transfer the rotary motion of the electric motor to the reciprocating action of the hedge-trimmer blades. Engineers designed both partsto take advantage of P/M: Neither part requires any machining or finishing.
Carbon City Products makes the 71-tooth, 26 diametrical pitch helical gear using FX-1005-110HT material, compacted to a 6.6 g/cc minimum green density and copper infiltrated to a 7.4 g/cc typical density.
The compaction process has to sequence the withdrawal of nine core rods, while allowing the lower punch to rotate 15 degrees during ejection without negatively affecting tooth form or profile.
Ceromet produces the two-piece sinter bonded cam using FX-1008-110HT material, copper infiltrated to a 7.35 g/cc typical density. The cam is comprised of two subcompacted preforms that are assembled prior to sintering and are mechanically and metallurgically bonded during the thermal process.
Each component is also quenched and heat tempered by conventional heat-treatment.
Metal Powder Components, Ceromet, and Carbon City Products are operating companies of Metal Powder Products Co., Indianapolis.
—Andrea Baker, Associate Editor
CAD compresses seat design cycle
Columbus, IN--With four months remaining before their biggest trade show of the year, engineers at Cosco decided to dramatically redesign the seat of their popular indoor baby swing.
The previous swing model paired an older seat design with a new quiet winding function that automatically swings the seat to lull the infant to sleep. The challenge for engineers was to update and add functions to the seat to better reflect the swing's new capabilities--in time for the show.
Cosco teamed with engineers at Compression Engineering, Indianapolis, to meet the aggressive design schedule. Engineers chose Pro/ENGINEER software from Parametric Technology, Waltham, MA, to do the mechanical design, as well as to evaluate materials, mass properties, and manufacturing issues such as moldability. "Amongother things, the software allowed us to check interferences on the seat's telescopic pivot motion for reclining," explains Cosco Senior Industrial Designer Dennis Turner.
Engineers used CAD to identify the best wall thickness for the seat's injection-molded polypropylene components. Pro/ENGINEER calculated the seat's center of gravity and other mass properties throughout design--including the assembly mode--to allow concurrent design.
CAD software helped Turner and Compression Design Engineer Tony Charameda design the seat's spring mechanism as a single DuPont Delrin® part. In earlier seat designs, the spring consisted of a resin handle, metal stamping, and separate spring. Engineers then used CAD data and laser sintering to produce a full-scale prototype of the part before the rest of the seat was completed.
The design was finished in time for the show. "The seat has better ergonomics and holds a larger child more safely and comfortably," says Turner. Adds Charameda: "Even though the pace of the project was accelerated, the technologies allowed us to check everything from safety to manufacturing without walking away from the computer."
Folding camper features seamless top
Somerset, PA—A lot of happy campers hit the road last summer—and if they were travelling in the new Coleman® Folding Trailers by Fleetwood, they should have been dry as well. The campers are said to feature the industry's first true one-piece, seamless, leak-proof roof.
The new top uses a patented composite-technology system that consists of two thermoformed ABS panels reinforced and bonded with a low-density, rigid polyurethane foam system. Offered by Bayer Corp.'s Polymers Div., Pittsburgh, the Baytherm® 929 foam system delivers light weight, flowability, processability, and structural support to the composite package.
The roof, featured on Coleman 10- and 12-foot folding trailers, replaces a seamed sandwich top that consisted of a painted aluminum outer skin, expanded polystyrene foam core, and plywood/vinyl interior layer. The new roof, developed in conjunction with composite systems technology from Advance USA, East Haddam, CT, significantly reduces parts manufacturing operations and production man-hours, say Fleetwood designers.
A cross-section of the final roof, which varies in thickness from 1/2 inch to 11/2 inches, consists of an outer panel of weatherable ABS, the Baytherm 929 rigid foam system, internal reinforcements and secondary parts, and an inner panel of ABS. Bayer's rigid foam creates an I-beam support effect, and also helps bond the two ABS panels.
"We needed a material that was highly elastic, yet rigid," says Michael O'Neill, president of Advance USA. "The foam also had to have good flow to fill these large parts, as well as good adhesion. The Baytherm system has performed to our expectations."
"Our goal was to streamline manufacturing, while getting a roof that had improved aesthetics, weatherability, and ruggedness," says Dana Gehman, product development manager for Fleetwood. "We got all that and more."