Engineering News 7634

Focus sharpens on high-definition TV

Paris-Even its biggest proponents can't deny that high-definition TV has had its problems.

First Japan invested heavily in an analog standard, but that's expected to be obsoleted by digital technology. In 1992, a European standards effort ran into problems with ground-based systems that couldn't handle HDTV-quality pictures. And in the U.S. that year, the Federal Communications Commission declined to adopt a standard among six that were proposed.

Today, HDTV is once again riding the crest of a wave of media attention. But things have changed. Rather than focusing on building an HDTV standard that would pack more pixels into a video image, the European community has turned its attention to developing a digital transmission standard. More than 130 companies, competing for digital business in Europe, have formed the Digital Video Broadcasting Group aimed at giving consumers a tremendous range of channels, based on standard television technology and digital services.

Considered a model of successful business communications, the DVB has agreed on a European digital transmission standard based on ISO-adapted Moving Picture Expert Group (MPEG)-2 standards as well as standards that address compression and multiplexing issues. Essentially, DVB compatibility will provide the key platform for multi-vendor interoperability in compression, channel coding, and modulation techniques. The first digital transmissions target cable and satellite applications.

For broadcasters, the opportunities are far-reaching-simulcasting the same service to facilitate a gradual transfer from analog to digital technology-or even simulcasting two different TV services in analog and digital format to target different audiences.

"The European community is focusing on the flexibility that digital transmission services can bring to the consumer," says Tony Wechselberger, executive vice president of TV-COM International, San Diego, CA, whose major business is in Europe, with centralized operations in Amsterdam. "It means getting many more TV channels and receiving all kinds of digital services."

The results of the effort are already showing up. In Paris, Eutelsat, the large European satellite consortium with operators in 44 countries, is simulcasting both analog and digital television signals in a single 36-MHz Eutelsat satellite transponder that does not require any extra cost to the broadcaster. And, already a number of European hardware firms including TV/COM International, Fuba, Nokia, Philips, Tandberg, and Thompson are designing decoders either for simulcast reception or for reception of a package of DVB digital television channels. Thousands of boxes are expected to be delivered throughout Europe by the end of this year.

Alliance sets the stage. In the U.S., the spotlight is focusing on the efforts of the digital HDTV Grand Alliance, formed after the FCC's Advisory Committee on Advanced Television Services (ACAT) encouraged digital HDTV groups to merge their best features into one system.

Since then, the Grand Alliance, consisting of industry giants AT&T, General Instrument Corp., Zenith Electronics Corp., the Massachusetts Institute of Technology, Thomson Consumer Electronics, Philips Consumer Electronics, and the David Sarnoff Research Center, has focused on a best-of-the-best digital HDTV system. It has successfully field-tested the transmission subsystem and constructed a prototype. Three years in the making, the final design-a new flexible, open architecture system-is undergoing tests at the ACAT. Experts predict that the prototype may well be adopted by the FCC as early as the end of this year. If it is accepted as the U.S. digital HDTV standard-test results may be available next month-actual sets could be on the market by 1997.

"Design engineers are going to have a ball," says James Carnes, president and CEO, of the David Sarnoff Center, Princeton, NJ. "The integrated circuit and device technology already exist to make it happen. There will be tremendous opportunities to make high quality video and audio products."

The prototype incorporates progressive scan transmission capability and square pixel capability, attributes that are extremely important for promoting interoperability with computers and telecommunications. Key features include:

Digital video compression technology based on proposed international standards. The compression system is based on MPEG-2 parameters, including the use of "B-Frames," a bi-directional motion compensation that improves picture quality.

"The companies were so devoted to addressing compatibility and interface issues early on that equipment integration was reasonably clean," says John Mailhot, technical manager, AT&T, Murray Hill, NJ. "In fact, the biggest challenges were not technical, but getting the companies to communicate so that the components could be successfully integrated."

Because of the Grand Alliance system's interoperability between entertainment television and computer and telecommunications technologies, the digital HDTV standard is expected to play a major role in the establishment of the National Information Infrastructure (NII). Many analysts believe digital HDTV will be the engine that drives deployment of the NII by advancing the development of receivers with high-resolution displays and creating a high-data-rate path to the home for a multitude of entertainment, education, and information services.

What about a European digital HDTV standard? "It will happen, but realistically, after the turn of the century." says May Wilkhund, information manager at Nokia's headquarters in Finland.

Standards a big issue. Despite the tremendous support for the new U.S. HDTV proposal, there is the thorny problem of broadcast standards-or rather the lack of them.

The North America Digital Group (NADG), Washington D.C., newly formed in October, may head off such issues. Consisting of over 60 leading organizations representing the programming, satellite, cable, and consumer electronics manufacturing industries, NADG is launching an on-going process to reach consensus on digital compression standards for North America that will be built on the existing international ISO MPEG-2 standards.

"The NADG is taking a tip from the success of Europe's VBG," says MA/COM International's Tony Wechselberger, who spearheaded the formation of the group. "Simply being MPEG-2 compliant is not enough-it's merely the beginning."

In fact, digital HDTV is considered to be in general disfavor with the U.S. broadcasting industry-despite the fact that the FCC is willing to offer a second broadcast channel, an extra 6-MHz spectrum, free for conventional TV and HDTV to be broadcast simultaneously. "The broadcasters do not want to be told how to use that spectrum. They want the flexibility of using it for other services as well such as data transmission," says Paul Dykewicz, editor of the HDTV Report at Phillips Business Information, Inc., Potomac, MD. "At this point, the major obstacle that stands in the way of digital HDTV is politics."

Perhaps Japan's high-definition analog TV, NHK's Muse, currently broadcasting in almost 20,000 households, best exemplifies the havoc politics can play in technological commercialization. Many industry officials believe the Japanese have locked themselves out of this arena by investing hundreds of millions of dollars in an analog system that cannot play in an all-digital television world.

Lessons learned may prove to be the winning card to success in digital transmission and HDTV as the industry moves, this time with a little more wisdom, into the next era of telecommunications.

'Innovation with Teflon' award winners honored

Orlando, FL-Packard-Hughes Interconnect, Irvine, CA, walked off with the Grand Prize at the 1995 DuPont Plunkett Awards for Innovation with Teflon(R). The firm also captured first place in the Electrical/Electronic Category for its fully additive method of fabricating electrical circuitry using the fluoropolymer film. Award winners received their honors at a special awards ceremony at the Disney World Yacht Club Resort.

Packard-Hughes Interconnect's Gold Dot(TM) technology involves electroplating copper on a stainless-steel mandrel coated with Teflon FEP fluoropolymer resin. The mandrel has either a pattern of grooves filled with Teflon, or a surface pattern of the material that includes spaces for copper deposition. Raised contacts are formed as part of the plating process in depressions in the mandrels. After plating, the circuits are adhesive-laminated to DuPont's "Kapton" polyimide film. The Gold Dot contacts resulted in interconnect products for multichip modules.

This was the first time that the U.S. awards recognized winners in three categories -Electrical/Electronic, Chemical Process, and "All Other Uses."

W.L. Gore & Associates, Inc., Elkton, MD, took the top prize in the Chemical Category for its ONE-UP(R) pump diaphragms. Gore reports that the innovative, one-piece diaphragm design and manufacturing process results in a product that lasts up to six times longer than similar diaphragms for air-operated pumps. The patented construction is said to offer strength, increased flex life, and abrasion resistance for enhanced environmental protection, quality assurance, reliability, and cost reduction.

W.L. Gore also received the top honor in the All Other Uses category for its Glide(R) dental floss. Only two years after its introduction, the floss, made of expanded monofilament fibers of Teflon PTFE fluoropolymer resin, has captured the second leading sales spot in the U.S.

Special-recognition citations also were issued in the three categories.

Electrical/Electronic-Tensolite Co., St. Augustine, FL, for its Tufflite 20000(R) airframe wire.

Special awards also were presented to entries from Europe and Asia:

Europe-(first prize) Koch Konstruktive Membranen GmbH, Rinsling, Germany, for Velaflex(R) heavy fabrics of Teflon fiber for variable-geometry membrane constructions; (second prize) IFK Isofluor, Neuss, Germany, for a fluorescent lamp tube covered with a shrink-fit jacket of Teflon FEP that contains glass splinters in case of breakage; (third prize) La Tecnochimica S.r.l., Torino, Italy, for the Swan-Protector Duplex, a thin coating of Teflon on corks used to stopper wine bottles.

Cray Research rolls out 'wireless' supercomputer

Eagen, MN-Engineers with a fat pocketbook and dire need for computing power may now have the ultimate analysis tool available to them. Cray Research has unveiled its long-awaited T90 family of supercomputers, a series of machines with a top speed of 60 billion calculations per second and a top price of $35 million.

The CRAY T90s are the fastest vector machines ever built by Cray Research, which has dominated supercomputing for the past 20 years.

Key to the T90s' high performance is a series of internally developed technologies. Those include no internal wiring, 50,000-gate chips, and 52-layer printed circuit boards.

The most startling design change is the machine's lack of internal wiring. In the past, supercomputers have typically housed thick bundles of wires that connect processor modules to memory. The CRAY C90, for example, used 36 miles of wiring.

In the new family of machines, engineers eliminated the need for copious amounts of wiring by replacing wires with electrically activated zero insertion force (eZIF) connectors. Each eZIF connector contains a pair of electrically-activated jaws. One set of jaws clamps onto a processor's pc board; the other attaches to a memory module. Four hundred contacts within each connector replace 800 wires that would ordinarily connect processor to memory. Each board employs five eZIF connectors, eliminating 4,000 wires per board.

The connectors were critical for the T90 design because otherwise, engineers would have needed to squeeze about 40 times as much wiring that exists in the older C90 into the new machine. Engineers say that the wireless design also enhances the machine's manufacturability and reliability because it simplifies the connection scheme.

The new machine's 52-layer boards are also an industry high, the firm says. Each incorporates a mile or more of interconnect wiring. Integrated circuits are mounted on both sides of pc modules, producing circuit densities of 800,000 gates within 2 nanoseconds' reach of one another.

The T90 family ranges from air-cooled single-processor systems to liquid-cooled, 32-processor systems. Prices start at $2.5 million.

Parallel vector supercomputers solve computationally intensive problems, such as fluid flow over an aircraft wing, or simulating complex manufacturing processes.

PTC to buy industrial design software

Waltham, MA-One of the youngest of the major CAE software companies will purchase part of one of the oldest in the industry.

Parametric Technology Corp. (PTC) has announced that it will buy the industrial design and visualization products of Salt Lake City-based Evans & Sutherland Computer Corp. Price: $34.5 million cash.

Specific Evans & Sutherland products to move under the PTC banner: the Conceptual Design and Rendering System (CDRS) and 3D Paint, tools used largely in industrial design for creating free-form surface models of automobiles, appliances, and sporting goods.

"This move indicates our desire to broaden our product line," says Amanda Radice, vice president of marketing services at PTC.

Even without the acquisition, users of PTC's Pro/ENGINEER software could import CDRS data via IGES transfer. Ultimately, says Radice, they would be able to do both industrial and mechanical design in the same system.

That has been difficult in the past. Software analyst Gisela Wilson of IDC says that industrial design has always been a stepchild, and its data hasn't been precise enough for detailed engineering. But, she says, the acquisition of CDRS and 3D Paint will help PTC sell more into its installed base of Pro/ENGINEER users.

Software speeds analysis of nuclear-storage tanks

Richland, WA-Westinghouse Hanford Company (WHC) recently used SDRC's I-DEAS Master Series software to develop and analyze safer, double-shell nuclear-storage tank designs for the clean-up of the Department of Energy's (DOE) Hanford site. WHC engineers say I-DEAS' interactive capabilities saved approximately $2 million by helping to drastcially cut down on analysis time. The software also allowed them to create and analyze more sophisticated designs, and helped establish safe operational limits.

With I-DEAS' interactive mode, on-screen graphics, and advanced display tools, fewer engineers developed and studied four complex tank models in just four months. Such a project previously took two years.

The I-DEAS-based tank models allowed Westinghouse to examine how liquid waste temperatures and various soil, liquid, or pressure loadings affect tank integrity and deformation. High temperatures, in particular, are a key concern since they can cause additional degradation of the outer, reinforced-concrete shell.

Westinghouse's new tank designs use two steel liners and a reinforced concrete outer structure to prevent radioactive waste leakage. ANSYS finite-element analysis software and Silicon Graphics, Inc. workstations were also used to model and analyze the DOE's long-term storage tanks.

Blade-maker cuts development time

Givat Shmuel, ISRAEL-Blades Technology has slashed product-development time up to 50 percent, thanks to CAD/CAM software that streamlines the process from design through production.

Blades Technology, formerly Iscar Blades, supplies turbines for companies including Pratt & Whitney, General Electric, and Rolls Royce.

"With turbine blades, it is essential that you create an accurate surface model," says Yacov Rubenstein, CAD/CAM supervisor. "The system we used previously was too complicated and lacked Cimatron's flexibility in surface modeling." In addition, engineers have not encountered data-translation problems, Rubenstein notes. "With Cimatron, we know we won't be held up by IGES."

Blades Technology takes a finished CAD model, scales it up two-fold, and creates tool paths for an epoxy model. That model is then scanned by laser, digitized, and scaled down 50 percent to generate toolpaths to mill a graphite electrode for the forging die (the electrode is not milled directly, because the softer epoxy is easier to work with). An exact computer model is crucial for this process.

Cimatron software is also used to test the blades. In one example, Blades Technology creates a plane section to obtain a theoretical curve for the blade. The actual blade is then measured using an electro-optic device, and the two are compared. If there is an error of more than 0.002 in, the blade is rejected.

Says Rubenstein: "Not only have we cut development and production time between 25 and 50 percent, we have cut costs and improved quality."

System watches drivers' blind spots

Cupertino, CA-Thirteen percent of vehicle collisions result from motorists' inability to see blind-spot objects while changing lanes, according to the U.S. Department of Transportation. The SideMinder(TM) crash-avoidance system invented by Autosense, Denver, CO, aims to help reduce this hazard. It uses infrared sensors and light-emitting diodes from Siemens Components' Optoelectronics Div. to alert drivers to blind-spot objects when they're negotiating congested freeways or city streets.

Blind spots are the areas on the left and right sides of a vehicle that the driver cannot see in the side-view mirrors. "The intent of the system is to reduce the need for over-the-shoulder, direct viewing of the blind spots, which takes the driver's eyes off the road ahead," says Autosense President and SideMinder inventor Warren Hyland. The system gives information only about the blind spots, so drivers will continue to use their peripheral vision and mirrors to see vehicles behind and next to them.

A driver activates SideMinder by engaging the turn signal. Sensor modules in the vehicle's tail-light assemblies include an IR transmitter, receiver, detection circuit, application-specific IC, and self-test circuitry. Beams from the transmitter reflect off objects in the blind spot, the detector receives them, and the IC processes the information. If the module detects an object, the LED arrays in or near the driver- and passenger-side mirrors flash.

Prototype vehicles using the SideMinder are currently on the road in the U.S. and Europe. Siemens estimates that the system will cost less than $50 in production quantities and should be available for 1997-model-year cars and trucks.

Critical ring material helps certify jet engine

East Hartford, CT-In a test rig, an explosive charge intentionally blows out the root of a jet engine's fan blade rotating at 3,000 to 4,000 rpm. To pass the test, the released blade must not penetrate the engine case, risking damage to the aircraft. Test engineers also must demonstrate that, after the release, the engine can be shut down safely with assurance that other structures in the engine can withstand the severe imbalance.

This worst-case scenario took place recently on high-thrust PW-4168 and PW-4084 jet engines at Pratt & Whitney's engine manufacturing plant. The 36-inch-long titanium fan blades, weighing more than 20 lbs each, fit into a slot in the fan disc in the front of the engine. The blade lock retention ring-30 inches in diameter, .75 inch wide, and 3/8 inch thick-hooks around the slot, acting like a large lock washer.

When P&W ran a blade-out test at red-line speed, using an AISI 4340 steel retention ring, the fan blade following the released blade punched through the lock ring like a "cookie cutter." The engine case ovalized from the impact, while following blades dug into the case wall.

Facing the need to do a redesign or find a new material, P&W project managers elected to try making the blade lock ring of AerMet(R) 100 alloy from Carpenter Technology Corp., Reading PA. The alloy consists of a nickel-cobalt steel strengthened by carbon, chromium, and molybdenum.

P&W engineers found that they could not break the AerMet 100 alloy blade lock. In fact, they discovered that the rings would withstand six times the force that broke the steel rings, and that they would do nothing more than deform under the impact.

Early in the investigation, P&W did not know how much improvement it could expect using the alloy retention ring. As a result, the engineers designed a blade catcher to use in the event the ring did not perform as desired. However, the ring held up so well that P&W eliminated the blade catcher. This translated into a weight savings of 25 lbs and $3,000 to $4,000 per engine.

With the alloy ring in place, P&W passed the critical FAA certification test, and, in the process, improved design, reduced weight, and lowered production costs. The P&W project team feels that test results have "clearly advanced the state-of-the-art in our understanding of blade-lock failure mode, method of loading, loads, energy, energy absorption, and design philosophy by a quantum leap." P&W has since used the alloy for blade locks in all of its large jet engines.

Subcontractor becomes first flow-sensor user

Plainville, CT-When Gems Sensors Division was developing the RF-2500 Series of RotorFlow(R) flow sensors, it used a subcontractor-Harkness Industries of Cheshire, CT-to form the polypropylene molded units.

While molding the bodies of the plastic versions, Harkness President Al Hoodboy saw that he had an application for the flow sensor. By installing several RotorFlow units into the cooling systems on his molding equipment, he found that he could more easily monitor the critical temperature control process.

"Within a couple of weeks we had them on our own equipment," says Hoodboy. "Tolerances are so critical that if proper core cooling isn't maintained, we need to stop and not make another part until the problem is fixed. RotorFlow gives us the warning we need."

RotorFlow sensors are available in three configurations: RFI, which provides a simple, visual indication of flow; RFO, for flow-rate monitoring or metering applications; and RFS, for specific flow setpoint switching.

Harkness uses RFI models now and is evaluating the RFS models for alarms and flow data. "A nice safety feature is that there are no buttons to push-you can walk along and glance at it," Hoodboy adds.

Electronic control synchronizes process line

Tar Heel, NC-When Carolina Food Processors Inc., a division of Smithfield Packing Co., opened its new 510,000 sq ft pork-processing plant, the physical size and layout of the building represented a major challenge. The problem: The company needed to synchronize the processing line.

"The plant has four overhead chain drive conveyors of different lengths diverging in different directions at different speeds," explains Henry L. Morris, executive vice president of Smithfield Packing. "But these separate conveyors must arrive at the inspection station simultaneously."

Carolina installed a conveyor system from Numark, Inc., Kenesaw, NE, that features an electronically geared synchronizer from Astrosystems, Inc., Lake Success, NY. The controller links multiple shafts to a single master without mechanical coupling.

Now, the four conveyors that bring parts to the inspection station are geared together at varying ratios. The overhead conveyor carrying the entire hog is the master. As it advances through the workstations, various parts are removed and placed onto conveyors that will parallel the master and arrive at inspection stations for simultaneous inspection as a single unit.

Another benefit of the new system: speed can be controlled by a single potentiometer on the master shaft. This allows continually adjustable control while maintaining synchronization. Changes can be made through simple keypad entries. Adds Morris, "The new system has given our operation additional flexibility."

SPARC-based workstation fits in a notebook package

San Diego-RDI Computer has designed an 8.5-lb SPARC-based portable notebook-sized workstation featuring an 85-MHz processor, 2.4 GBytes internal disk storage, and optional 1024 x 768 flat-panel color display.

The PowerLite 85 "provides the desktop-equivalent capabilities workstation users need to run computer- and graphics-intensive applications," says RDI President U.C. Moon. The system is powerful enough to run mechanical CAD software, he adds.

Can mechanical engineers now take their UNIX-based CAD applications on the road? Jim Brennan, senior director of Workgroup Technologies, Hampton, NH, says the technology already exists; what is lacking now is market acceptance.

"When I go on a plane, most people are using spreadsheets or word processing," he notes, not CAD. "Engineers are seemingly more conservative than other users. It may take longer."

However, he envisions engineers using a portable workstation like the PowerLite 85 in hotel rooms, or to take to other worksites when visiting suppliers or customers. RDI says one early user, at Ford Motor Co., carries his portable workstation to different buildings on the sprawling Ford campus, working with engineers to develop design software.

As portable UNIX workstations become more powerful and affordable, Brennan says they may become substitutes for conventional desktop machines- especially if they are designed to fit in desktop "docking stations." That way, they could be easily used with full-sized monitors, and then slipped out for portable use.

The PowerLite 85, which is bundled with the Solaris UNIX operating system, is rated at 64 SPECint92 and 54.6 SPECfp92 (measures of integer and floating-point performance, respectively). There are two display options: a 1024 x 768 flat-panel color display, or Colorplus 640 x 480 active-matrix LCD. Hard-drive options range from 520M to 4.4G internal, with additional external options; and memory from 32M to 96M. The system measures 2.2 x 12.75 x 11.2 inches; pricing starts at $11,995.

Sidekick aims at affordability

Newton, MA-With the release of the 1995 Sidekick, Suzuki seeks to capture the "affordable" end of the sport/utility market. The top-of-the-line, four-door JLX with four-wheel drive starts at $17,269; the more modest two-wheel-drive canvas-top JS with two doors lists at $11,699.

At $18,406, the four-door JLX hardtop Design News tested offered automatic transmission, air conditioning, and a built-in roof rack. Standard features on the JLX include rear-wheel anti-lock brakes, an alarm, locking spare tire, cruise control, and power outside mirrors, windows, and locks.

The Sidekick's 1.6-l, single-overhead-cam engine produces 95 horsepower at 5,600 rpm and 98 lb/ft of torque at 4,000 rpm. Although the engine posts EPA fuel efficiencies of 22 mpg city, 26 mpg highway, there is a performance penalty for the little four-cylinder. The engine labors in some off-highway conditions, such as hilly back roads. Overdrive and a lock-up torque converter in the four-speed automatic transmission help to compensate.

To further accommodate driving demands, Suzuki engineers gave the driver a choice of shift patterns in the automatic transmission. A two-position switch in the "two-mode preference" option package lets the driver choose between normal shift patterns for best fuel economy, or "power" mode. The boost, while not enormous, does improve pep.

Standing 66.5 inches tall, the JX and JLX models boast a generous 7.9-inch minimum running ground clearance. Engineers capitalized on the vehicles' height by giving the driver plenty of glass and a utilitarian instrument panel for outstanding overall visibility. The drawback: A high center of gravity and fairly stiff suspension make the vehicle feel top-heavy and somewhat unpredictable in turns, despite a curb weight of more than 2,800 lbs.

If your driving habits involve some rough roads, the Sidekick's interior pads and grab-bars should put your passengers at ease. Potholes and unpaved road surfaces are no threat to the suspension. In front, it uses MacPherson struts with coil springs, a stabilizer bar, and dual-action shock absorbers; the rear combines coil springs with trailing arms.

Remote-control lawnmower braves hazardous turf

Escondido, CA-Need to cut the grass in your yard, but afraid of excessive radiation exposure? Such concerns may seem the exclusive domain of paranoid landscapers. Yet until recently, workers at the Zimmer nuclear plant outside Cincinnati, OH, had to don hot, sweaty radiation suits to trim select acreage.

Now, thanks to a remote-control lawnmower designed by Remtron (Escondido, CA), cutting the grass at Zimmer may prove as easy as pushing a joystick.

The $45,000 unit consists of a large industrial mower, provided by eXmark, modified with a custom Remtron remote-control system. A radio transmitter equipped with two joysticks and a variety of knobs mimics the operation of most of the lawnmower's functions. It sends signals to a receiver/processor box mounted to the top of the mower. Inside, a standard Remtron remote-control board (the company's primary business is with overhead bridge cranes, locomotives, and backhoes) runs a custom program developed for the lawnmower.

Two linear trim servos, supplied by Menzimer Aircraft Components (Vista, CA), control the throttle and choke. ETI Systems (Carlsbad, CA), designed a second set of servos that pushes and pulls the hydraulic control arms to vary the speed of the drive wheels. Each of these larger servos outputs 20 in-lbs of torque at 1 rpm. Custom amplifiers, designed by engineers at Remtron, power the servos.

"The biggest challenge," says John Schooley, Remtron's president, "was to maintain the manual control capability of the mower while being able to convert it to remote control very easily." Ultimately, engineers developed a series of electrical and mechanical disconnects that allow workers to switch configurations in less than five minutes.

While the cost is a bit steep for suburban lawns, Schooley believes the company can cut the price to less than $25,000 in quantity.

Digital mock-ups slice jet design time

Belfast, Northern Ireland-The Shorts aerospace company has developed a digital mock-up for its latest project, the Learjet 45 corporate jet-a move that will help cut development time by an estimated two years.

"We've captured every single aircraft part in 3-D solid models, which means we've completely eliminated the need for traditional, wooden prototypes," says Willie Magill, CAD/CAM systems manager. Shorts-which won what it calls the world's first aircraft contract, to build six "Flyer" byplanes for the Wright Brothers in 1909-will be building the Learjet 45's fuselage and em-pennage. The Learjet is expected to go into flight testing in less than five years, compared to the usual seven.

When working on the coupe rail, for example-a curved, alloy component that forms a structural link between the plane's windscreen and cockpit roof-engineers traditionally test assembly of the design with a wooden prototype. With the Learjet 45 digital prototyping, though, the cockpit design team simply pieced together the coupe rail's different elements on the workstation screen. Engineers discovered six major "clashes" in the initial design, and ironed out the problems within two days.

Magill credits electronic data management software (EDM) for assisting that process. EDM helps ensure that the 300 to 400 engineers working on the project-including subconractors hundreds of miles away-all have the latest, correct versions of designs; it also tracks who is working on what task. The company uses Computervision CADDS CAD software and CV's Engineering Data Manager software running on networks of Sun workstations and servers. Short engineers also rely on packages from Patran, Nastran, Formtek, ICAD, and FrameMaker.

The system gives engineers more access to design data, Short officials say. Before, an engineer designing a hydraulic system would have a difficult time calling up design information on the layout of the structural area into which those components needed to fit. Obtaining a single file could take hours, even days. Now, engineers can tap into one of the 10,000 design models or drawings within seconds.

"We wanted to completely break down the wall between the design side of the house and the manufacturing side," Magill adds. "It's paid off handsomely for us."

Piston pump powers automatic clutch

Leamington Spa, UK-Engineers at the Oildyne division of Commercial Intertech Corp., Minneapolis, have developed a new hydraulic unit to power an automatic clutch system (ACS) for cars. The ACS, designed and developed by Automotive Products, is being used with a standard transmission for the "Twingo Easy" compact city car from French automaker Renault.

To actuate the manual clutch, the ACS uses a miniature piston pump with built-in relief and check valves and a 12V dc motor from Oildyne. In operation, a microprocessor signals the unit to actuate the clutch.

Because the ACS and the miniature piston pump operate with brake fluid, engineers had to address several challenges. To suit high under-hood temperatures and brake fluid's low viscosity, Oildyne engineers selected the model HP1000 piston pump. "We chose an all-steel construction for uniform thermal expansion properties and iron-nitride surfaces for lower friction," explains Oildyne's Director of Engineering Dave Mauch.

Engineers at Oildyne, Automotive Products, and Renault used a 525,000-cycle durability test as well as a 250-hour salt-spray/salt-mist test and vibration tests to qualify the ACS system. They also conducted thermal shock tests at -22 degrees F to 212 degrees F, and tested cold-starting at -22 degrees F.

The hydraulic power unit shows promise for ABS and other dynamic brake applications, says Mauch, because the multi-piston pump is quieter than the one- and two-piston pumps presently used. Oildyne engineers are developing a prototype parking brake actuation system using similar technology.

Design News releases directory on CD

Newton, MA-Engineers who are anxious to find a particular component or system as quickly as possible have one more resource to turn to. Design News has recently issued its OEM directory in CD-ROM format.

Like its print counterpart, the CD-ROM directory provides users with access to 7,000 suppliers and links to more than 2,300 products.

But because of the flexibility of this new media, says Vice President of Electronic Publishing Peter Urbach, the CD-ROM can offer more than just listings of supplier names and product numbers.

"Users can not only access product descriptions, but a number of product specifications, too," says Urbach. "And since this information is compiled in one source, users seem to find this feature most useful-not to mention the ease of search."

Users can locate a supplier, even if only a product trade name is known. A geographic locator is also included, allowing users to find suppliers by region, state, and zip code.

Other tools available on the disc include:

An industry reference tool with detailed IEEE, ANSI, NEMA, and National Fluid Power Association standards information.

The OEM directory on CD-ROM, which is being distributed to 10,000 qualified engineers, is presently available in Windows 3.1 format only. Retail copies can be purchased for $97.