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Articles from 1997 In December


Designer's corner

Designer's corner

Mini display

Holographic light-shaping diffusers, manufactured by Physical Optics Corp. (Torrance, CA), diffuse the LED so that the mini display can be comfortably viewed with both eyes open.

The user sees an image comparable to viewing a 20-inch diagonal display from a 5-ft distance. Designed for easy mounting in various OEM products such as cell-phones and pagers, the CyberDisplay is small, light weight, consumes little power, and is low cost.

For evaluation, Kopin offers a kit that includes the CyberDisplay, backlight, lens, and electronic control unit.

Jeff Jacobsen, Kopin Corp., 695 Miles Standish Blvd., Taunton, MA 02780; (408) 636-5556.


Adjustable locking hub

Locking hub achieves angular adjustment increments of less than one degree, and a small steel prototype has been tested to withstand more than 6,000 lb-in.

Equal spacing between adjacent pins and sockets in conventional locking hubs traditionally limits the minimum angular adjustment. If spacing is 10 degrees, then the minimum adjustment usually cannot exceed 10 degrees.

By varying the angular spacing between locking pins on one hand and adjacent sockets on the other--and using fewer locking pins than sockets--this design achieves minimum angular adjustments in increments of less than one degree.

The design can be manufactured in steel, plastic or aluminum. Possible applications include articulating arms, tooling, ergonomic and operator-assist devices, adjustable exercise equipment, and camping equipment.

William Sbordon, Adjustable Locking Technologies, 27350 Southfield Rd., Ste. 114, Lathrup Village, MI 48706-3409; (248) 443-9664.


Hollow-fiber membrane

For existing engines or retrofit, membrane modules enrich nitrogen content in air stream to reduce NOx.

Next generation EPA constraints for heavy-duty diesel engines call to reduce NOx/bhp-hr from 5 to 2 g, and from 0.6 to 0.2 g for light-duty trucks. A hollow-fiber membrane module, between turbo charger and engine, enriches the air stream with nitrogen.

Injecting 81% nitrogen-enriched air (NEA) into combustion chamber reduces NOx 50-70%, with no significant increase in smoke or CO, and 3% power loss. Optimized fiber and module design results in a system size of 0.65 cu ft or less.

Jack Stoppi, DuPont Co., Barley Mill Plaza, P-10 1284, Wilmington, DE 19880-0010; (800) 533-1313.


Ball bearing/freewheel clutch

Modified balls slide past saw teeth enabling free rotation in one direction, then twist to transmit torque in the other.

One-way clutches, used in transmissions and other devices, usually employ separate bearings to support shaft during freewheel operation. Combined ball bearing/freewheel clutch carries high torque and features positive lock up.

Inner and outer race hold modified balls in grooves. Balls, flattened on either end, press against saw-tooth ridges on inner and outer race extensions. Balls slide by saw teeth in one direction. In reverse direction, a slight wobble makes one or more balls tilt to engage saw teeth.

John Roberts, GTE, P.O. Box 7188, Mountain View, CA 94039-7188; (650) 966-4260; FAX: (650) 966-2951; or e-mail John.E.Roberts@GSC.GTE.com

Hot products

Hot products

Extend gear life with clean steels

It's a tough world out there for gears, which are routinely exposed to heavy loads, bending stresses, and frictional forces. To increase both the performance and the fatigue limit of components, researchers at the Timken Co. are continuously working on methods to produce cleaner steels and to better control steel composition. Why? The amount of non-metallic inclusions in steel has been correlated with lower gear life. Timken's newest offering is a modified 4615 alloy, which is produced by an air melting process in an electric air furnace, extensive refining, and a strand cast process. And the alloy is exhibiting extremely good performance. "In given applications, we've improved gear life significantly" says Craig Darragh, product technologist.The Timken Co


Near-net shapes invar extrusions

For designers seeking to minimize thermal expansion mismatch, Invar-36(R), a specialized nickel alloy, is an attractive option. And Plymouth Tube Co. is now offering near-net shape invar extrusions. Invar's low coefficient of thermal expansion (0.72 in/in/ degrees F x 10-6 at 200 degrees F to 4.22in/in/ degrees F x 10-6 at 700 degrees F makes it particularly ideal for tooling components used in the production of composite structures. "By using Invar-36 tools, warpage can be minimized," says Dennis Gudgel, marketing manager for Plymouth Extruded Shapes. "And with near-net extruded shapes," he adds, "designers can eliminate a lot of costly machining and waste." Parts must have a maximum cross-section design that fits within a six-inch-diameter circle. Average maximum length of a finished part is 30 feet.
Plymouth Tube Co


New alloy toughs it out

Tool breakage is a frustration for any machine shop. But a new alloy developed by Carpenter Specialty Alloys specifically for tools is preventing the problem and getting kudos from the field. Called AerMet(R)-For-Tooling, the iron-cobalt-nickel alloy possess high hardness and strength, combined with exceptional durability and toughness. According to Carpenter, the alloy is designed for components that require a combination of HRC 53/55 hardness with the highest toughness available. AerMet(R)-For-Tooling is an air-hardenable alloy virtually free of distortion when properly heat treated. minimal distortion is a definite advantage when making parts with critical tolerances or complex shapes.
Carpenter Specialty Alloys


New apps for Be-Al alloys targeted

The idea of partnering beryllium with aluminum in a single alloy with high specific strength and stiffness has long been an attractive one. In a joint development effort in the early 1990s, the partnership of Nuclear Metals and Lockheed Martin Electronics & Missiles made a breakthrough in learning how to investment-cast beryllium-aluminum alloys. Called Beralcast, these alloys consist of beryllium, aluminum, cobalt, and either silicon or germanium. Historically, they been used primarily in aerospace applications, such as the F-22 jet fighter. Now the company is targeting commercial markets where a high-strength-to-weight ratio is desirable, says Frank Venbaco, such as sporting goods equipment and medical prostheses. The company, which has recently changed its name to Starmet Corp, will market the alloys under its new Starmet Comcast subsidiary.
Starmet Corp.


Castable graphite cuts machining time

A new castable graphite, called Hyper-Cast, is now available for producing net shape parts. In developing the material, Frank Gojny had to overcome one major obstacle: Traditional resin systems used to bind very fine-grain graphite particles have a low decomposition temperature. "The challenge was to develop a material with a higher ash content, giving it an essentially unlimited temperature range," says Gojny. Castable graphite has a number of advantages over monolithic graphic. The net shape parts produced require less machining. And, claims the inventor, Hyper-Cast graphite shows superior strength and abrasion resistance. The higher strength is attributed to the carbonaceous bonds of the chemical cross-linking. A trial size (1 gallon castable liquid, which equals 231 cubic inches of cured material) of the material is available for $175.00.
Hyper Industries


Molten metal sensor has extended range

Haraeus Electro-Nite, the company which pioneered the concept of disposal sensors for the metals industry, continues to push the envelope. The company has recently introduced the Model DT-260 portable digital temperature measurement system for molten metal. According to Electro-Nite's Bob Kuball, the new system is compatible with a wider range of materials, including brass, aluminum, and bronze. A new design for the leadwire offers longer pole life and requires less maintenance. As with its long-lasting predecessor, the DT-250, Kuball expects the DT-260 to meet the needs of customers for the next decade.
Haraeus Electro-Nite


Carbide-tipped bandsaw is tough

Titanium alloys, stainless steel, and other materials with a high degree of hardness are notoriously difficult to machine. But a new carbide-tipped bandsaw blade just introduced by Sandvik Saws & Tools Co. can improve cutting productivity in tough-to-machine materials by as much as 3X. In one comparison, involving a type 17-4 stainless steel, the new Series 3868 blade improved cutting rates by a factor of 3.25. The secret is a tool design that produces equal chip thickness, resulting in a smooth cutting operation. Unlike other carbide-tipped blades, the teeth are not subject to premature chipping. And finishes are equal to that of bimetal blades.
Sandvik Saws & Tools Co


Salt bath nitriding improves properties

An alternative to conventional heat treating methods, ferritic nitrocarburizing enhances the properties of ferrous metals. According to the Kolene company, its SBN(TM) processing method increases wear resistance and improves fatigue strength by as much as 100%. A low coefficient of friction and a tough surface layer allow excellent sliding and running properties, reducing seizing and galling.
Kolene Corp.

Connectors tread new ground

Connectors tread new ground

Look at the person sitting next to you on your next business flight. While your travel kit may not necessarily include them, chances are his or her briefcase arsenal includes a PC or PDA and a cell phone not much bigger than a family-size pack of chewing gum. The growing market for such downsized and portable products, which leapfrog the capabilities of their predecessors of only a few months, is driving down the size of the connectors within--much like what is being seen in the companion-component technologies of relays and switches (DN 11/3/97). Material advances, as well as new fabrication techniques and design configurations, are driving the downsizing effort.

Currently, PCI-standard bus connection needs are being met with ingenious strategies for increasing processing density in products. Packaging-improvement devices include the Elco (Huntingdon, PA) Mezzanine Card Connector System that enables a host CPU board to be customized by mating PCI cards to it in parallel stacks 8 to 15 mm high. These board-to-board connections feature a rugged leaf-contact configuration for secure mezzanine-board mating, according to John Ashman, director of engineering. Other PCI adaptations include the company's Compact PCI connectors, which repackage up to five rows of 2-mm pitch interconnects, with shielding, for right-angle configurations.

Mini Mate-N-Lok 2 connectors feature a two-piece locking mechanism for each connector half that is produced in a single injection mold. The female contact uses a split triangular cross section that gives four points of contact rather than the two found with circular contact halves.

As mobile communications and other devices, such as PCs and PDAs, pack more functionality into increasingly smaller packages, Ashman notes metal shielding for impedance matching may not be adequate in the future. The reason is the need for signal conditioning as clock speeds increase. "Standard pin-socket impedance is becoming a major portion of the impedance budget a designer has to contend with," he says, since impedance for other components is decreasing. Also, for many current connectors, impedance is not consistent from connector to connector while, in the future, pin-to-pin impedance will have to be consistent to allow signal tailoring for each line.

As clock-speed requirements over 300 MHz kick in for many connectors, impedance matching will encompass not merely line-to-line matching but signal tailoring. Thus each line will require an inductor, capacitor, or resistor. "And all of these will have to fit within the same envelope as the basic connector," adds Ashman. "You can't increase size in impedance-matched connectors since volume is critical." In some portable devices, the I/O connector is already the largest component after the display screen. "Until now, impedance matching has been a luxury only for the military and Cray because of cost," says Ashman. As a first step, a unique low-cost fabrication process will allow Elco to build such circuitry line-by-line for production multifunction connectors beginning in 1998.

Unique fabrication methods developed by Elco enable production connectors with individual impedance-match pins to be on the market in the coming year.

Power management critical. As devices shrink, available power must be husbanded. Lifetimes can be lengthened by improving basic battery longevity, lowering power-interconnection resistance, and cutting on-board power consumption. Power-using parts, for say a PDA, include a microprocessor, hard drive, and display. As flash memories replace hard drives and display efficiencies rise, connectors may become a major drain above what is now roughly 10% of the power budget. Currently standard-contact connectors have a resistance around 3{OMEGA}, with higher-cost gold contacts at about 1{OMEGA}. In the future, Ashman notes common connector resistance will have to be in the m{OMEGA} range as well as rugged enough where many disconnects and reconnects occur, as in docking or recharging stations.

Materials and new designs are leading the downsizing charge. New flowable polymers with higher dielectric constants can be molded in thinner sections for tighter-pitched pins. Wall thicknesses approaching 0.005 inches are possible, down from three times that. And locating mating contacts on the thinner shear (cut) edges rather than the wider stamped side reduces the width of the pins, Ashman adds.

Size is not the only factor influencing connector design. As electronics increasingly replace mechanical systems in many applications, designers are finding they are not an exact one-for-one substitute. In appliances such as washing machines and dishwashers, mechanical systems are typically located within top fascias and doors, where the conditions include harsh heat, humidity, and shock. To survive in these environments, electronics, including connectors, must be more robust and adequately sealed.

AMP (Harrisburg, PA) has recently introduced splash-proof and immersible seals for its existing Mate-N-Lok connector line. The system uses a TeflonTM seal template around the wires coming out the back end of each connector half, and an insert with triple ridges for the actual connector interface. With the Teflon parts, the sealing capabilities are not destroyed if the connector is undone. As an accessory that can be fit to an existing connector, the cost is only $0.15 per mated line, as opposed to the $0.50 per line for dedicated connectors.

A new adaptation of the Mate-N-Lok concept, the Mini-Universal 2, has a molded pin on each side of the connector block in which the wires are inserted. Each pin rides within in a corresponding slot on each side of its wire-locking cap, which forms the mating interface. Even before they are snapped together to form a ridged connector for mating, the cap and block cannot be removed from each other and lost. A unique injection-molding machine with movable dies on two sides, as well as the top and bottom, allows the production of the attached pin and slot pieces in a single mold.

Gender bender. Likewise, Phoenix Contact (Harrisburg, PA) shows design legerdemain in its Inverted Mini-Combicon reduced-pin-spacing terminal-block connectors. Previously available for larger-spacing, higher-power control-panel applications, these PCB connectors can be gender-switched via adapters. Such interchangeability allows numerous board-to-board and board/wire mating arrangements and geometries, as well as wire-to-wire mating. The gender of the original cable or board connection need not be changed.

Finally, what connector developments might users of these devices be looking for? One perspective is offered by Robert Boyes, marketing manager for Poly-Flex Circuits (Cranston, RI). "For flexible-circuit manufacturers, directly interconnecting multiple boards is a driver for the coming years," he says. The reduction in thickness and increase in complexity of such circuits will dictate connectors that are "flex friendly"--that is, without any need for bulky and expensive additional packaging to adapt the "flex" to the rigid board or other electronic hardware. "Future applications will require very thin yet incredibly reliable connectors," Boyes concludes.


MEMS the word

Connector manufacturers continue pushing pin counts up and pin pitch down while needing to accommodate ever-increasing data rates. After the turn of the century, new technologies should be available to improve pin number and density, and clock rates, by several orders of magnitude, according to Barry Cammarata, director and senior technical advisor in the AMP Corporate Technology Office (Harrisburg, PA).

"Within five years, IC sockets will have I/O counts between 2,000 and 3,000," he notes. "With this large number of pins, the force requirements for insertion and extraction will be too great, requiring a switch to more complex and costly zero-force designs." And clock rates look to at least triple from current numbers into the GHz range--dictating accounting for signal characteristics, including cross talk, switching noise, and series and parallel termination--adding complexity to connector design.

One technology set that addresses these critical interconnection issues is MicroElectroMechanical Systems (MEMS) based on integrated circuit fabrication techniques. "While integrated circuits exploit the electrical properties of silicon, MEMS devices take advantage of both the mechanical and the electrical properties," notes Cammarata, "and include microminiature motors, pumps, switches, actuators, sensors, and mirrors--all of which can be integrated with CMOS electronic circuitry on the same chip."

MEMS micromachining methods include:

Bulk micromachining that removes silicon wafer material by etching.

  • Sacrificial surface micromachining which adds materials to, as well as removes them from, the wafer surface. Typically, a layer of silicon dioxide is vapor-deposited onto the surface and then chemically etched into required shapes.

  • Lithogafie Galvanik Abeforming (LIGA)--from the German for lithography, electroforming, and molding--which uses X-ray lithography, micro-electroplating, and micro-molding to create "tall" structures on silicon with submicrometer resolution. These structures have lateral dimensions of a few microns and heights up to 1,000 microns.

Currently, to reduce connector-pin pitch, several companies are developing "Z-axis" contact devices having Z-axis motion, but no X- or Y-axis contact wipe. These are "contacts with bumps, dots, or butt contacts," and have pin pitch as low as 0.1 mm, says Cammarata. "MEMS microconnectors can potentially reduce pin pitch by a factor between 100 and 1,000 from that of Z-axis devices, while maintaining good mechanical and electrical characteristics. Typical MEMS devices exhibit 8 microns of topography which will define the small contact surfaces needed for microinterconnection."

MEMS microconnectors can work over a wide range of voltages, from below 1V expected in many future interconnections to hundreds of volts needed for some mechanical actuators. And their on-chip electronics can handle many of the demanding requirements of very-high-speed signals.

The next generation. But Cammarata says even before MEMS come of age, a successor is rapidly moving over the technology horizon. This new carbon--not silicon--based technology could reduce the size of electronic and mechanical components to molecular scale. It hinges on the physics and chemistry of fullerenes--a form of carbon in a spherical lattice structure of 60 atoms in hexagonal faces. The structure is called buckminsterfullerene (or "buckyballs") for its resemblance to the geodesic domes created by Buckminster Fuller. "The mechanical properties of fullerene devices suggest that they can match many of the mechanical functions of MEMS, but on a thousand-fold smaller scale," Cammarata adds.

While pure C60 is an insulator, once buckyballs are doped with alkalimetals they conduct, and the packing structure becomes a 3-D organic conductor. "This suggests the possibility of forming monolithic, nanoelectronic devices or systems that have distinct regions of insulating, semiconducting, conducting, or even superconducting properties, in addition to photoconduction, luminescence, or magneto-resistance characteristics," says Cammarata.

As for interconnection within and between such systems, he notes fullerenes can include structures with increasing numbers of carbon atoms. "As more atoms are included, the sphere elongates and becomes a capped tube, with open-ended versions also possible. Called "buckytubes" or "nanotubes," they are stronger than steel and there is speculation that they eventually will be produced with any desired length, kilometers and beyond! Cammarata concludes that "nanotubes with electrical conductivity 10 to 100 times that of copper at room temperature are a possibility. Such nanotubes would be the ideal, ultimate small wire for interconnection in nanoelectronic systems."

Linear motion industry in flux

Linear motion industry in flux

Technology is in the driver's seat today. And a major challenge facing companies in the industry today is a shortage of engineering and machine operator talent, says Robert Humphrey, president of Humphrey Products.

Design News: Fluid power is a relatively mature technology--at least when compared to electronics and electro-mechanical technologies. How has the industry managed to stay current?

Humphrey: Two things: From an engineering standpoint, we are constantly striving to reduce the size of our products while at the same time increase their overall performance and reliability. A valve today needs to fit in roughly half the space it did 20 years ago, while offering the same or greater value to the customer from an operational standpoint. All components are getting smaller, and of course, electronics are having a great influence in today's designs.

From a manufacturing standpoint, you don't see the congested plants of the past with their wall-to-wall inventory. Here at Humphrey, we've implemented new manufacturing practices that enable us to make our products to order and get away from the old "batch"mentality. That has helped to cut our inventory levels in half.

Q: Do you see any great shift away from pneumatic or hydraulic systems to electro-mechanical designs in linear motion systems?

A: When you talk about linear motion systems, there are four issues to address: price, speed, accuracy, and power. All of the technologies you mention have their specific strengths and specific weaknesses. While electro-mechanical systems are getting a lot of press, their biggest disadvantage today is the price. But we can expect to see that come down over time. In fact, they're getting less expensive all the time. I'd say in ten years that a large percentage of the linear motion devices are going to be based on electro-mechanical designs. This business is in a constant state of flux, and these days no one can afford to stay standing still.

Q: What is the major challenge the industry is facing today?

A: Far and away it has to be the availability of qualified people in engineering and on the shop floor. Experienced engineers--we hire mechanical and electrical engineers--are at a premium today, particularly those engineers who have a diversified background. At the entry level, the average mechanical engineering student coming out of school has very little or no background in fluid power. If we want the workforce of the future to have the technical skills that industry will require, companies are going to have to form closer ties with our educational system. Humphrey, for example, is working closely with our local universities to promote engineering and help shape the curriculum so that the engineers of tomorrow are better prepared to enter the workforce.

On the shop floor, it is even more difficult to find individuals who are qualified to operate the highly technical processes we employ. Our educational system has failed us in providing students with even a rudimentary education.

Q: What do customers want in a supplier of linear motion systems?

A: Although customers are always looking for the highest quality product at the lowest price, I think from a very basic standpoint customers are looking for reliability--reliability of design and supply. Designers do not want to put a device or system into a multi-million-dollar piece of assembly equipment, only to have that device fail prematurely and the entire machine go down. To its credit, I think the industry has made tremendous, tremendous strides in boosting the reliability of fluid power systems. Today's systems are designed to last at least as long as the equipment they are going in to. Beyond that, I think customers are looking for vendors that are staying on top of technology and are willing to push the envelope in terms of new products. The vendors that are most successful in doing this have formed very close relationships with their customers.

Q: What are the specific advantages to the customer in partnering with a supplier?

A: The great advantage in a partnership is that the supplier is able to get involved very early in the design process. Often the expertise that the supplier brings to the partnership can provide input that improves upon the original design. When suppliers and customers work closely together, the design cycle is often dramatically reduced, too. And everyone recognizes what a powerful competitive weapon time-to-market is today.

Energy savings turn on better motors

Energy savings turn on better motors

We're all going to die.

No we're not.

This about sums up the level of public debate now raging over whether so-called "greenhouse gases" will alter the Earth's climate if emissions continue unabated. The United Nations environmental conference in Kyoto, Japan, this month probably will not produce the dramatic reductions in carbon dioxide envisioned at the Rio Summit earlier in the decade.

The issue also is focusing attention on what engineers can do to reduce air pollution. Energy use is viewed by many as the most significant contributor to carbon dioxide emissions. ACEEE estimates electric motors operating in the U.S. account for more than half of the electricity consumed in the country. Therefore, the adoption of energy-efficient motors has become an important factor in reducing emissions.

Engineers are being encouraged not only to come up with more energy-efficient designs, but to specify existing designs that consume less power to get the job done. Increasingly, such encouragement has the force of law behind it.

For example, the terms of the Energy Policy Act declare that most general-purpose motors sold after October 1997 must meet standards of energy efficiency as defined by the National Electric Manufacturers Association (NEMA). Certain high-torque and low-horsepower motors are exempt, and some vendors are encouraging customers to consider these motors as alternatives to expensive upgrades.

Most applications will be affected, however, and in all likelihood there is an energy-efficient motor in your future. Fortunately, most major motor manufacturers produce both standard motors and high-efficiency motors. According to NEMA, energy-efficient motors, also called premium- or high-efficiency motors, are 2-8% more efficient than standard motors.

The cost of clean. Efficiency comes with many other benefits, NEMA adds. The organization reports:

"Energy-efficient motors owe their higher performance to key design improvements and more accurate manufacturing tolerances. Lengthening the core and using lower-electrical-loss steel, thinner stator laminations, and more copper in the windings reduce electrical losses. Improved bearings and a smaller, more aerodynamic cooling fan further increase efficiency. Energy-efficient motors generally have longer insulation and bearing lives, lower heat output, and less vibration.

According to Jerry Peerbolte, vice president of marketing at Baldor Electric Co. (Ft. Smith, AR), the new standards offer customers an opportunity to select better performing motors. "The energy-efficient motors run cooler and with less vibration," Peerbolte says. "This means less stress and longer life."

All is not wine and roses, however. The initial cost of energy-efficient motors can be 15-30% higher than for a comparable standard motor, and payback is affected by motor size, energy rates, and operating hours per year. "Although energy-efficient motors cost more than the standard line, they are usually justified on a payback basis, since they consume less energy per horsepower," points out an Allen-Bradley white paper entitled "A Comprehensive Guide to Understanding Motor Fundamentals."

Michael Offik, manager of product marketing for Reliance Electric in Atlanta, GA, notes the life-cycle costs for energy-efficient motors are better than for previous standard-efficient motors. "The economics of energy-efficient designs are attractive in the long run," Offik says.

For those companies that must convert, the U.S. Department of Energy (DoE) sponsors the Motor Challenge program. The industry/government partnership encourages companies to select efficient motors, pumps, fans, and other motor-driven equipment. By encouraging the most appropriate matching and integration of these system components, the DoE expects to help manufacturers realize 2 billion kW-hr per year of electricity savings by the year 2000.

Participants in the Motor Challenge program have reported successes. Minnesota Mining and Manufacturing (3M, St. Paul) formed a Motor Challenge team that evaluated approximately 1,000 electric motor systems in 29 buildings at the 3M Center to identify feasible projects. In one of the first facilities evaluated as part of the project, four key motor upgrades reduced electricity use by 41% and resulted in cost savings of $77,554 per year. 3M estimates the company's savings for all surveyed facilities at 10,821 MW-hr.

Lockheed Martin Armament Systems was looking for a way to improve the performance of the ventilation system at its industrial plating plant in Burlington, VT, where electrical costs are highest of any Lockheed Martin plant in the country. A variety of small and large machined metal parts are plated, anodized, finished, and cleaned at the facility.

In all, the plant consists of nine plating production lines with 64 tanks handling 19 different plating processes. The constant volume ventilation system provides exhaust for lateral hoods over the plating dip tanks, and prevents toxic fumes from escaping from the tanks into the workers' area. The system has 10 motors ranging in size from 5 to 100 hp.

The best solution proved to be the addition of variable frequency drives (VFDs), which permit variable-speed control of the motors driving the ventilation fans. This allows the ventilation supplied by the fans to be matched to needed levels at any given time automatically. The new variable-output ventilation system includes nine electronic VFDs, which reduce airflow to 55-65% of full speed during idle times.

Lockheed Martin reports the benefits of the new system include a 38% reduction in electric and natural gas utilities costs, fewer emissions, and improved system and emergency ventilation control. The VFDs are not only used to increase system energy efficiency, but also to improve process control, overall productivity, and product quality while reducing wear on equipment and lowering maintenance costs. The project cost approximately $99,400 to implement and has resulted in annual savings of more than $68,000, providing a simple payback of just under 1.5 years.

Not all motor selection projects need to be so large-scale in order to see benefits. Appropriately enough, the DoE has developed a software program, called MotorMaster+, that can be used to identify inefficient or oversized inventory motors and compute the energy and demand savings associated with selection of a replacement energy-efficient model. The software includes an annually updated internal database containing price and performance information for more than 10,000 currently available NEMA Design B motors. The latest 2.0 version of the software also includes data on NEMA Design C and D motors, in addition to a number of specialty types.

MotorMaster+ is a Microsoft Windows-based computer software application designed to support motor management functions at medium-sized and large industrial facilities. The program includes a motor inventory and field measurement storage repository capability and an energy conservation analysis function that can determine energy savings, dollar savings, simple payback, cash flows, and after-tax rate of return-on-investment.

All-in-all, there need not be such a conflict of interests between energy and economic efficiency.


What is an energy-efficient motor?

The energy-efficient motor differs from a standard motor in both design and manufacturing techniques. It employs larger stator conductors with higher conductivity. The rotor bars are larger as well, to reduce the overall copper (or aluminum) loss, which comprises 55-60% of total motor losses. The motor flux density and air gap are reduced to minimize the magnetizing current required. Stator and rotor laminations are thinner to increase resistance to the flow of eddy currents. More laminations are added to the core stacks as well, producing a longer stator and rotor for increased torque.

Hysteresis losses, which are normally 20-25% of the total motor losses, are reduced by using silicon steel instead of low-carbon steel for the laminations. As a result, the motor uses less current, has better power factor, and runs cooler. Since the energy-efficient motor runs cooler, ventilation requirements are reduced, allowing a smaller fan to be installed. Windage loss (typically 5-9% of total losses) decreases and the smaller fan runs quieter. These motors are less susceptible to damage from impaired ventilation and also operate well at higher altitudes. Cooler operation also increases motor life.

Insulation life is up to four times longer--an important fact, since insulation breakdown is the primary cause of motor failures. Bearing lubrication lasts longer too, doubling the interval between required lubrication. Cooler operation means that less burden is placed on air conditioning equipment. Energy-efficient motors can also operate in higher ambient temperatures without requiring extra cooling, which in the case of a standard motor, could add substantially to the purchase price of the motor.

Energy-efficient motors are also more rugged than standard motors, tolerating greater fluctuations in applied voltage, voltage imbalance, and overload. Some can even tolerate 30-40% overloads for prolonged periods. They are also capable of starting higher inertia loads than standard motors because of their increased thermal capacity.

Source: "A Comprehensive Guide to Understanding Motor Fundamentals," published by Allen-Bradley.


Using MotorMaster+

The MotorMaster+ software program enables users to find just the right energy-efficient motor for the right application. It also provides many supporting functions, including:

Motor inventory management

  • Maintenance log tracking

  • Conservation analysis

  • Savings evaluation

  • Energy accounting

  • Environmental reporting

MotorMaster+ 2.0 can be acquired through the DoE's Motor Challenge Website at: www.motor.doe.gov/mcssoft.asp


Applications for VSDs

Variable-speed drives are most suited to the following motor types:

dc brush-type servo motors

  • ac or dc permanent-magnet brushless servo motors

  • ac non-vector induction motors

  • ac vector induction motors

Source: The Mike Kilroy Corp., Dayton, OH

Comparisons Between Standard-efficiency (SE) and Energy-efficient (EE) Motors
Motor (hp) Purchase Cost ($) Efficiency (%) Annual Savings Payback (years)
SE EE SE EE kW-hr $
10(a) 614 795 86.5 91.6 2,103 210 0.86
25(a) 1,230 1,608 88.1 94.2 6,004 600 0.63
50(a) 2,487 3,207 90.6 95.0 8,352 835 0.86
100(a) 5,756 7,140 90.7 95.7 18,822 1,882 0.74
200(b) 11,572 13,369 94.6 96.1 10,782 1,078 1.67
300(b) 15,126 18,385 94.6 96.0 15,111 1,511 2.16
Note: Based on 16 hr/dy operation at 75% load and $0.10/kWh
(a) Reliance Standard-Efficiency and Premium-Efficiency motors
(b) G.E. Standard-Efficiency and EnergySaver motors
Product news

Product news

Inverters

MasterDrives(R) family of ac inverters are for motion-control and closed-loop applications. The MC version of the Micro/MidiMaster ac inverters are f

The ultimate housekeeper

The ultimate housekeeper

Armies of robots today perform any number of dangerous and perilous jobs, such as inspecting nuclear waste and handling explosives. But developers at Cyberclean Systems, an office cleaning company, have built an android capable of handling what just might be the most disagreeable task known to man: custodial work.

The mobile cleaning robot, called Dottie, tidies up entire office buildings in four- to six- hour shifts of continuous work without complaint. On board she carries an industrial-strength vacuum, 22 times more powerful than the household-type, and capable of sucking up even large objects such as crumpled paper or small pets. And at about four times the productivity of a human janitor--cleaning up approximately 8,000 to 18,000 sq ft of floorspace per hour--she's a real bargain to boot.

According to John Holland of Cybermotion, the company that supplied Dottie's mobile platform, she is one example of a growing number of robots being recruited for stupefyingly dull or disagreeable jobs. To wit, his company has already put into service close to 100 guard robots, some capable of sensing an intruder by using up to six different technologies.

But don't throw out your Hoover just yet. The number of robots entering the workforce is going to have to go way up--and prices way down--says Holland, before a robot like Dottie will be making affordable house calls.

Highlights from Autofact 1997

Highlights from Autofact 1997

Autofact '97 hosted more than 300 companies exhibiting computer-based tools that promise to reduce costs, increase productivity, and improve time to market. The show started off with a bang as Computervision announced its purchase by Parametric Technology Corporation. CV also debuted its new DesignWaveTM CAD system for Windows 95 and NT. ...Intergraph announced Solid Edge version 4, which includes expanded part modeling using helical features. ...SolidWorks showed off SolidWorks 97Plus, while in the same booth, Working Model Inc. demonstrated its Working Model simulation software. ...Matra Datavision debuted Euclid Stylist, the surface modeling package for its Euclid Quantum CAD/CAM system. ...Microcadam displayed its Helix CAD products and played host to SRAC, which introduced its COSMOS/M for Helix package. ..."Supplier readiness" was the theme of SDRC's exhibit, which emphasized its capabilities in automotive applications. ...MCS, Inc. introduced Anvil Express featuring Autosnap 3-DTM for automatically creating solids from a 2-D drawing. ...Ashlar Vellum showed off its Vellum Solids, a hybrid program that combines wireframe, surface, and solids modeling. ...Visio Corp. demonstrated its new IntelliCADTM software, which offers compatibility with AutoCAD drawings, commands, and applications at a cost of $499. ...Smart Solutions Inc. previewed a Web-enabled module for its PDM system that lets authorized users access PDM files through browsers over the Web. ...Engineering Animation Inc. introduced VisNetworkTM software. It enables quick access to distributed data and works seamlessly with CAD and PDM systems. ... Hewlett-Packard displayed a full-scale mock-up of the Predator sports car--the result of a collaboration between car designer Mark Gerish, HP, ICEM Technologies, EDS Unigraphics, MSC, and Engineering Animation. ...Spatial Technologies showed off ACIS 3.0 along with several ACIS-based applications, including CADKEY 97 from Baystate Technologies. Baystate also announced the planned December release of CADKEY 97 version 2. ...Building Block Software introduced Journeyman CAMTM, which provides 2- and 2.5-axis milling directly inside CADKEY 97. ...Microsoft featured an art-to-part demonstration of how managers can run an entire company in a Windows NT environment.

Look a little deeper

Among new products at The MacNeal-Schwendler Corp. booth were MSC/DropTest, for drop and impact simulations; MSC/SuperForge, for simulating forging operations; and version 3 of MSC/NASTRAN for Windows. ...CADSI launched DesignWorks, which offers motion, structure, and thermal analysis embedded inside SolidWorks. ...ANSYS showed its DesignSpace 3.0 Stress Wizard and Vibration Wizard. The wizards are plug-ins to solid modelers such as Autodesk's Mechanical Desktop. ...ITI introduced CAD/IQ software for analyzing CAD model integrity and interoperability with downstream applications and CAD/CAM/CAE systems. ...Invention Machines Inc. showcased the IM Phenomenon module for its Invention Lab series of engineering support software. The program permits engineers to uncover known physical, chemical, and biological principles that could be used to solve a given engineering problem.

More than pretty pictures

Silicon Graphics, Inc. provided the first widespread public demonstration of RealityMapping, its new 3-D software rendering technology. ...LightWork Design Ltd. showed version 4.0 of its LightWorks rendering engine. The company also broke new ground with Rapidprove, its new automated machine toolpath checking software. ...The central display in 3D Systems' booth was the company's new SLATM 5000 stereolithography machine. The SLA 5000 reportedly has the highest power solid-state ultraviolet laser available in stereolithography today. It uses less space and power than its predecessor and doesn't require water cooling. ...Prosolvia Clarus introduced Oxygen SketchMap software which converts 2-D sketches into a 3-D virtual reality environment for faster automotive design. ...Seiko Instruments introduced ColorPoint PS 7114-CGM2, a desktop color imager that prints CGM files from any application without downloading the information, regardless of the vendor, application, or hardware.

Engineering News

Engineering News

From aircraft to ship design:
Get ready for a 'bumpy' ride

Providence, RI--More than a century ago, golfers noticed a curious phenomenon: Used golf balls flew better than new, smooth ones. Random patterns of dents on the used balls actually stabilized their flight and, in some cases, made them go farther. Eventually, the golf world incorporated that knowledge into the design of new balls, providing them with dimples.

Now, engineers may benefit from a similar phenomenon that offers potential improvements in disciplines ranging from aircraft design to pump operation. A recently published study in the journal Nature describes a technique for reducing skin friction drag by up to 13% on aerodynamic surfaces. Aircraft engineers say that if such reductions could be achieved on production aircraft, it would be a significant step forward. "When we try to reduce drag, we normally work in second decimal places," notes William W. Greer, vice president of engineering and quality assurance for Learjet (Wichita, KS). "So 13% represents a revolution to us."

Drag reduction has long been an area of concentration among aircraft designers, for good reason. Some estimate that a typical commercial aircraft can save between $100,000 and $120,000 a year in fuel costs by cutting overall drag just 1%. Worldwide, a 1% drag reduction could translate to fuel savings of more than $1 billion a year. What's more, the new technique could apply to a wide variety of other applications, including designs of ships, submarines, torpedoes, pumps, HVAC ducting, mixing machinery, and pipe flow systems.

Random pattern is key. The new reductions in skin friction drag involve the use of a simple aerodynamic surface geometry. Researchers Sture Karlsson, an emeritus professor of engineering at Brown University, and Lawrence Sirovich, director of the applied mathematics laboratory at CUNY/Mt. Sinai in New York, found that a random pattern of small bumps could lower skin friction drag. The size of the bumps, or so-called "chevrons," is determined by the thickness of the viscous wall layer on the aerodynamic surface, they say. Though the precise size of the chevrons is proprietary, they do describe them as being on the order of a "fraction of a millimeter."

The real key to the extraordinarily high reductions, however, is not the size of the bumps, but their overall pattern. Sirovich and Karlsson found that the chevron pattern must be random. When using a random pattern, they achieved skin friction drag reductions between 12% and 13%. In contrast, aligned bumps not only failed to lower the drag, they raised it by as much as 20%.

The theory behind their findings is complex, but it basically says that the random chevrons reduce "bursting" near an aerodynamic surface. Bursting, which is caused by low speed air streaks near the wall, is generally believed to be responsible for intense turbulence and, therefore, greater drag.

Sirovich and Karlsson aren't the first to employ surface geometry changes as a means of lowering drag. Researchers have been trying to find ways to "energize the boundary layer" for almost two decades. They've tried putting microscopic holes on aerodynamic surfaces to suck the boundary layer off, and they've applied grooves to wing surfaces to decrease turbulence. 3M Aerospace is currently testing Drag Reduction Film, which employs small riblets in the air flow direction. Used on an Airbus A-340, the film has been successful in reducing drag. Cathay Pacific Airlines applied it on one commercial aircraft that flies long routes, and it has achieved drag reductions of approximately 0.8%. "It has allowed Cathay to fly from Hong Kong to Toronto without a refueling stop," notes Tom Ihbe, 3M Aerospace market development supervisor. "Sometimes in the past, they had to refuel in Anchorage." Ihbe adds that the riblet film offered drag reductions ranging from 2-4% in wind tunnel tests.

Up to now, however, no one has achieved skin friction drag reductions as great as 12-13%. Because the figures are so high, some experts believe that airframe manufacturers might be inclined to invest substantial capital in it if the concept proves out.

Still, they warn, much remains to be learned about it. "Its success will depend on how it affects an aircraft's handling and sound characteristics," Greer says. "It will also depend on how maintainable it is and what it costs." One way to implement the concept, Greer says, is to program CNC systems to ma-chine the random chevrons into the wing skins during regular machining operations.

Business jet manufacturers might be willing to make such accommodations, not because of fuel savings, but because of the additional range the concept could provide. Greer says that the newest Learjet could extend its 2,000-mile range by as much as 120 miles by employing the concept. "For business jet operators, that's where the real advantage is," Greer says.

More than aerospace. Even if the concept ultimately loses its appeal to the aircraft industry, Sirovich and Karlsson believe that it offers advantages elsewhere. Like 3M's riblet film, which was used on Stars and Stripes in the America's Cup competition in 1988, the random chevrons could find application in the design of large ships and racing boats.

Bursting, which is caused by low speed air streaks near the wall, is generally believed to be responsible for skin friction drag. (Reprinted with permission from Nature; Copyright 1997; Macmillan Magazines, Ltd.)

Sirovich also believes that the concept could play a role on submarines. By reducing drag on a submarine's hull, the concept could enable submarine powerplant designers to employ less powerful pumps. As a result, submarines employing the concept would be more difficult to pick up on enemy sonar.

The concept could also play a key role in water pumping equipment. If used on the inside of a pipe, for example, it could reduce the horse-power required to pumpwater. As a result, it could be valuable for fire fighting equipment and water hydraulics systems.

Ironically, Sirovich believes that the aligned chevron concept, which raises drag by 20%, could eventually be as important as the random chevron idea. Because the aligned concept causes greater turbulence, it could serve in applications that require fluid mixing and heat transfer. In HVAC, for example, designers might employ it on the insides of air ducts. There, greater turbulence could cause more effective heat transfer. As a result, furnaces could use less powerful blower motors. The same technique could also serve in electronic package design, where more efficient heat transfer enables chips to run cooler, as well as in chemical mixing equipment.

Ultimately, the concept's success will depend on how well it can be replicated in further wind tunnel tests, and how effectively it translates to real-world engineering. If Sirovich and Karlsson's results are correct, a 13% skin friction drag reduction could lead to overall aircraft drag reductions of as much as 6.5%. (Skin friction drag typically comprises about half of an aircraft's overall drag.) But even if the concept only achieves one-third of that in actual application, aircraft manufacturers would be elated. "It's not yet clear how much real-world drag reduction we can achieve with this concept," Sirovich says. "But in our experiments it's been a factor of two better than any technique out there now."

What this means to you

Reduced skin friction drag could:

Extend aircraft range and cut fuel consumption.

  • Cut pumping power requirements.

Increased skin friction drag could:

Enhance heat transfer in HVAC and electronic cooling applications.

Design News readers who wish to learn more about this research may contact Lawrence Sirovich at chico@camelot.mssm.edu or Sture Karlsson at skf@cfm.brown.edu


Valve with integral electronics simplifies machine set-up

Leicester, England--The introduction of proportional valve technology has produced a level of performance in motion control beyond that obtainable with simple switching or manual devices. Now, flow or pressure control can be modulated with a low-power electronic signal to give true proportional control. Achieving the full potential of modern proportional valves with spool-position feedback usually requires an electronic amplifier to control solenoid current. Traditionally, this has been a separate rack-mounted card, but modern valves now have integral electronics.

In 1991, in response to market research, Vickers Systems introduced a range of proportional directional controls with a pre-set integral amplifier. At that time, Swiss manufacturer Heinrich Schmid Maschinen Werkzeugbau AG was quick to seize the opportunity to rationalize the power hydraulics on its automatic fine-blanking presses. Today, the integrated-electronics concept has progressed, with the latest Vickers KB series featuring a new amplifier design, together with full EMC and IP67 environmental ratings.

One successful user of Schmid machinery is Leicester Engineering Services, whose activities focus on automotive components. Its Schmid HSR 400 hydraulic presses develop a blanking pressure of 4,000 kN to produce, from coils of mild steel, up to 2,000 disk-pad backing plates an hour.

In a closed-loop control system, Vickers KBFDG4V-5 feedback-type directional valves, located on the side of the machine, control the position of two single-acting cylinders used for the approach and return of the main blanking ram. The direct-acting solenoid configuration of the units obviates the requirement for a hydraulic pilot reducer valve, increasing reliability. So much so, in fact, that the company has noticed a marked reduction in machine downtime with the new valves.

Vickers supplies its valves as factory-wired units fully tuned for gain and deadband. The control amplifier itself is integrated into a die-cast zinc housing mounted directly on top of the valve body, giving a low-profile, compact arrangement. Calibration of the valves at the factory also means that the plug 'n' play facility can be put to full use, allowing the valves to be quickly replaced for maintenance.

According to John Watts, maintenance manager at Leicester Engineering Services, the main benefit of the pre-set integral amplifiers is the enhanced motion control. As Watts puts it: "Whereas before, it was always trial and error with a screwdriver in the control cabinet; now I never even need to touch the factory settings." Also, he says that serviceability is improved now that the valve can be directly set up from the main PLC controlling the machine, rather than from a separate control cabinet containing the control card.


A generation change pays off

Munich, Germany--A "genuine" industrial PC is no cheaper than a programmable controller. At least that's the contention of BMW Planning Engineer Heinz Schwenk. That's why, despite all the industrial-PC hype in the manufacturing sector, BMW's Series-3 plant recently upgraded its Siemens S5 controllers to next generation S7s. In fact, Schwenk estimates that the upgrade actually cost 20% less than if BMW continued to use the S5s.

During the recent assembly line redesign, major goals included ergonomic and logistical improvements, and better use of floor space. Plant programming also had to meet IEC 1131 compliance, according to Schwenk. Because further development of the existing Siemens S5 controllers had largely been completed, BMW decided to use the S7 controllers to automate all transfer points on the new line.

BMW Plant Configuration
BMW's Series-3 plant recently upgraded its Siemens S5 controllers to next generation S7s.

Because of limited floor space, two existing lines were combined into one new line. The result: a complex assembly line, more than two kilometers long, that incorporates six different conveyor systems. Twenty S7-400s with 414-2DP CPUs control the conveyors and transfer points. Profibus-DP and distributed I/O systems link approximately 160 frequency controlled drives that are housed in more than 50 cubicles. Thanks to their double-bus structure, the distributed field devices and operator interfaces (OI) can operate independently of one another.

A total of 60 operator panels allows communication with controller and programming devices via a multi-point interface (MPI). This permits simultaneous programming at start up, as long as the same function blocks are not used. Linked via industrial Ethernet to the host computer, and to the existing ID system through serial I/O, the S7-400 proved adept at handling the entire communications spectrum on the plant floor during the pilot phase. And since reaching full capacity in September, no control problems have been reported.

Schwenk explains that the factory is ready for the future because the Profibus/S7 concept supports central control with an industrial PC, while electricians--with little knowledge of high-level languages--can easily maintain control on the factory floor.


Resin improves EGR-valve performance

Troy, MI--An electrically operated exhaust gas recirculation (EGR) valve promises to outperform vacuum-controlled systems in reducing auto emissions of smog-causing nitrogen oxides. The electrical heart of the EGR valve is a linear solenoid with a coil bobbin molded from DuPont ZeniteTM LCP liquid crystal polymer resin.

"Even though the solenoid's operating temperature reaches as high as 240C, the LCP material meets required mechanical strength, dimensional stability, and creep resistance," explains Siemens Automotive's Product Leader Gary Everingham.

Zenite LCP also cuts assembly costs, according to Everingham. The coil is mounted on the valve's metal stator by heat staking, an economical technique that was incompatible with previous thermoset bobbins. The bobbin's dimensional accuracy is crucial during automated coil winding, and its low creep ensures that press-fit terminals stay in the bobbin's integrally molded wells.

Thermotech, Division of Menasha Corp. (Hopkins, MN) molds the bobbin from Zenite 7130. Tom McNamara, Thermotech's director of research and engineering, says: "We know how to mold quality parts with many materials, but Zenite LCP is among the easiest to handle. It has excellent flow characteristics for filling complex molds."

Like all EGR valves, the Siemens unit controls the flow of exhaust gas back into the engine's combustion chambers in order to hold combustion temperatures low enough to reduce nitrogen oxide production. Precise metering of exhaust gas at different engine speeds and loads is crucial, according to Everingham. Too little exhaust gas fed back into the engine increases emissions; too much would reduce engine performance.

In contrast to vacuum-operated EGR valves, the car's on-board computer directly controls Siemens' electrically operated unit. "This speeds response to computer commands," says Everingham. Another plus for the Siemens valve is its built-in diagnostic capability, which transmits signals to the car's computer confirming proper operation. If malfunction occurs, the computer sends a control signal to alert the driver.


Snowboarding goes to extremes

Sun Valley, CA--Original snowboards were quite simple, looking similar to a water ski with a rope attached to the nose to aid steering. This design met riders' expectations in the 1960s. But current snowboard enthusiasts expect their equipment to do much more. Nowadays, they want to accelerate quickly, land hard, and be able to easily tote their boards up hills or wherever they want to go.

To make matters worse, some of those expectations seem to conflict. Snowboarding equipment must be strong, yet light. Firm, yet flexible. And what about price? Quality is important, but most sports-equipment consumers are price sensitive. Even high-quality equipment must be priced at a level the market considers appropriate.

To respond to what often appears to be irreconcilable demands, designers of snowboard equipment are eagerly exploring and experimenting with new materials--and some are having very good results. Aastro Molds, Inc., a maker of snowboard bindings, is one such company.

During its first year of binding production, Aastro experimented with a wide variety of materials, eventually approving a super-tough nylon. "For several years, the plastic material provided satisfactory performance for snowboarders," says Aastro Molds Plant Manager Randy Smith. "Recently, however, extreme riders told us our binding baseplate was a little soft and caused heel and toe lift when performing trick maneuvers. This was unacceptable."

In response, Aastro once again tested many glass-filled products which proved workable but made the bindings too heavy. Then the designer tried a polycarbonate, which seemed like a good solution. It provided the appropriate combination of flexibility and stiffness riders needed. However, after selling 3,000 pairs, the company was getting a high number of returns. It turned out that the salt used on roads at ski resorts attacked the material. In addition, many of the polycarbonate bindings showed stress cracks. Aastro continued its search for a superior material.

"We talked with Amoco Polymers (Alpharetta, GA) about our need for a lightweight material that was stiffer than the nylon we'd been using, had good chemical resistance, and would injection mold without any warpage or stress," Smith recalls. As if that order wasn't tall enough, Aastro needed a material that "wouldn't cost an arm and a leg," Smith adds.

Amoco suggested AMODEL(R) polyphthalamide (PPA) resin for the new binding material. The supplier thought the resin would be a good candidate due to its proven strength, stiffness, fatigue and creep resistance, and low moisture absorption qualities. Also, other manufacturers had found the resin worked well with conventional molding equipment, and did not corrode tooling or require intricate drying procedures.

"Not only did the material seem to have the product performance properties we desired, it also scored high on appearance qualities," Smith notes. "We'd been very disappointed with the surface appearance of the glass-filled materials we'd tested."

Using the new resin, Aastro Molds developed its Price BreakTM binding. The binding has the high-performance characteristics of expensive snowboard bindings, but at a price comparable with products at the lower end of the price scale.

After several months of heavy use, Aastro has experienced no breakage, no warpage, and no complaints about too much flex. In short, Aastro faced the challenge as an extreme snowboarder might: "Just because something looks impossible doesn't mean it can't be done." The Price Break bindings provide the proof.


CAPE leads to a competitive edge

Houston-Halliburton Energy Services is creating a CAPE (concurrent art-to-part environment) architecture that will bolster the firm's competitiveness well into the future. To attain this goal, the company standardized on Electronic Product Definition (EPD) products from Computervision Corporation (Bedford, MA).

Halliburton first recognized the need for new solid modeling products to replace old mainframe CAD software. Management then realized it needed a design automation strategy that would include an enterprise data management system as well. Halliburton standardized on Computervision's CADDS 5 software, and selected the company's Optegra products for its product data management (PDM) system.

At the heart of Halliburton's CAPE implementation, Optegra data management software features a distributed vaulting capability that enables users in different locations to share data as if they were in the same office.

Jim Landmark, Halliburton's Engineering Systems manager, expects Optegra's distributed vaulting feature to promote concurrent design and manufacturing, and to help the company reuse existing components within new-product designs.

"Eventually we may have distributed Optegra vaults in eight or more locations in the U.S. and overseas," he says. "Our intent is to store all product data in the vaults, in addition to CAD models. That would include engineering specifications, concept deliverables, engineering analysis results, and even NC programs.

"Also, we'll be able to standardize component libraries available to our engineers, so it will be easy for them to determine how they can reuse existing parts in new designs. This will help tremendously in saving costs and in cutting time-to-market for some new products."

According to Halliburton's CAPE timeline, the Optegra data management capabilities will be rolled out during the next two years. Eventually, as many as 11 groups, from design engineering to shop floor cells and suppliers, may be tied into the Optegra data management system.

"Even though we're now in the early stages, we're able to see how concurrent design and manufacturing will benefit from the ability to access up-to-date product information from different locations," says Landmark.

Moreover, the information sharing permitted by the Optegra vaults will help geographically dispersed teams design, assemble, and manufacture the increasingly complex system packages that will help Halliburton gain a competitive advantage. The company's Early Evaluation System product is one example.

"We'll have design engineers at one site and manufacturing engineers at another," says Landmark. "There will be about 15 or 20 people spread over two sites, and they'll be able to collaborate as if they're in the same building." "The key benefit will still come down to helping us get our products to market faster than competitors," says Landmark. "Our goal at this point is to see a general reduction in time-to-market of 50%. We think that is a realistic goal thanks to our CAPE strategy and Computervision's EPD product families."


Sensor checks tire pressure while you drive

Hannover, Germany--Be honest, how often do you check the tire pressure on your car? Once per week or per month? Or do you just give them a good kick? Soon a Tire Pressure Monitoring System (TPMS) will handle this chore for you and even monitor the tire pressure when the car is being driven on the road.

The manufacturer of the system, Continental Automotive Systems, estimates that approximately 80% of tire failures occur due to a gradual loss of inflation pressure. In response to this, the company has developed the TPMS, which continuously monitors the tire pressure and gives a warning well before a blowout can occur.

Weighing only 35 grams, the TPMS sensor, which is based on the piezo-resistive principle, is fitted to each tire valve between the wheel rim and the tire. From there it transmits the temperature-compensated inflation pressure to the control unit inside the vehicle using radio-frequency telemetry. The transmission frequency can be varied to suit national regulations; for example, 433 MHz in Germany and 315 MHz in the U.S. Each wheel transmits its own identification number. The control unit uses a sophisticated warning algorithm and checks all the data for plausibility before displaying the tire pressure to the driver.

The TPMS compares the pressure to a value set by the driver, and gives a warning if a trend is detected against the background of normal tire-pressure variations. The driver can therefore avoid the potentially dangerous situation of driving for too long on under-inflated tires. However, the system reacts immediately for a fast drop in pressure. Centrifugal forces should not present a problem, as the sensor module is designed to withstand speeds of over 300 km/hour.

Continental is currently subjecting prototypes of the system to long-term tests under arduous conditions. It expects to have the system to market in 1999.


New rules aim to slow down Formula One

Paris--Technical regulations introduced by FIA, the motor sports governing body, will result in new shapes but old speeds on the world's Formula One tracks in 1998. The main motivation has been safety but with a nod toward spectator appeal. Although some drivers have made derogatory comments about the changes, engineers have been unfazed.

Shaded areas show changes that will have to be made to the Tyrell '97 racecar to comply with the FIA's Formula One '98 regulations.

"Under the revised 1998 rules, the driver will have more room, more crash resistance, more rollover security, better fuel-tank security, indeed greater security all round," explains Max Mosley, president of FIA.

The most striking change will be the narrower appearance of cars, because the overall width has been reduced from 2 to 1.8m. At the same time the bodywork is a little wider to allow for a larger cockpit opening.

"I felt as though I had no grip at all," said Mika Salo of Tyrrell Racing after driving a prototype narrow car. "The speed through the corners was much slower, and I found myself having to use the whole of the track."

The use of grooved tires, mandated by the 1998 regulations, will add to the novelty. The trend in F1 for some years has been smooth tires with lower rolling resistance. The name for these tires, slicks, says it all.

The normal racing line on a course has better adhesion as the traffic has laid down rubber on the road surface from the passage of the tires. Stray off that line with slicks, and grip is poor. Yet overtaking requires drivers to accelerate off the normal racing line. With grooved tires, drivers should get as much grip off-line as on the normal racing line.

With narrower, slower cars and more equal grip on all areas of the track, there will be more opportunities for overtaking by enterprising drivers.

"The cars will be very different and I am sure we will get used to them," says Salo. The FIA has promised that with adoption of the latest safety improvements, there would be no other design changes affecting the chassis for a few years. The FIA plans to use tire regulations to keep lap speeds under control by deepening the grooves or increasing their number. With no chassis changes to worry about, it is expected that the smaller teams will be able to catch up technically with the bigger ones. In theory, this should narrow the technology gap and make for more open competitions.

The 20 or so firms involved in F1 production are now busily working on adaptations to their current designs. The 1998 season will show which companies have come up with the right answers.

For FIA Technical Regulations see www.fia.com


Parametric buys Computervision

by Paul E. Teague

Waltham, MA--Two major players in the CAD wars, Parametric Technology Corporation and Computervision Corporation, have announced a merger agreement. Under the terms of the deal, the Waltham, MA-based PTC will acquire Computervision in a stock-for-stock transaction expected to be completed in early 1998.

Computervision, also a Massachusetts-based company, will become a wholly owned subsidiary of PTC, which will continue to develop, maintain, and support Computervision products independent of its own Pro/ENGINEER product line.

PTC is the world's tenth-largest independent software company and a leading supplier of CAD/CAM/CAE software tools used to automate mechanical design. Computervision produced CADDS5 and supplies electronic pro-duct definition (EPD) solutions that allow users to create, manage, share, and reuse product information in a collaborative setting.

"Computervision was looking for a safe harbor for its customers," explains Wayne George, director of communications for the company. "Unfortunately, the financial challenges of competition got in the way of people buying our product."

For PTC, the acquisition provides access to industries such as automotive and aerospace, which the company has had difficulty penetrating, as well as to Computervision's large customer base. Perhaps more importantly, it gives PTC access to Computervision's Optegra product data management software.

This recent acquisition is the third in a string of mergers within the CAD industry. Several months ago Dassault Systemes bought SolidWorks. Even more recently, EDS Unigraphics and Intergraph agreed to form a new company for mechanical computer-aided design.


Solids reduce modeling time, speed conveyors to market

Arlington, TX--Many users of 2-D CAD believe solid modeling is difficult to use and slower than 2-D for creating initial models. But at Martin Sprocket & Gear Inc., Solid Edge software (Intergraph Corp., Huntsville, AL) enabled designer Dylan Malek to create hundreds of sprockets from scratch in four months. He estimates that creating the same number of sprockets in 2-D would have taken an entire year.

"A major factor in the decision to switch from 2-D AutoCAD to Solid Edge was reducing the time it took to revise existing designs," explains Malek, who works in Martin Sprocket's conveyor design division. "Previously it would have taken an operator using AutoCAD several hours to redo one sprocket. With Solid Edge, it happens in minutes." Once a new sprocket is created, drawings can be generated from the solid model in a fraction of the time it took to create them from scratch.

Although the ability to capture design intent quickly is important to Martin Sprocket & Gear, it is not what originally led the company to solid modeling. After nearly 50 years in business, Martin had accumulated a vast number of engineering drawings on paper.

But engineers often redesign existing parts because the original drawings are not easily accessible. This approach slows the design cycle and wastes valuable resources. In Martin's case, the lack of an electronic parts database hindered the company's ability to achieve fast turnaround on made-to-order systems, a large part of its business.

The conveyor division was particularly aware of this problem, because new systems typically combine off-the-shelf parts with those that are modifications of existing models. Several years ago, engineers decided to switch from 2-D AutoCAD to solid modeling. Explains Malek, "Every day, revisions are done to existing products because most of the things we do are made to order. We hoped that by creating parts as solid models, we could easily revise them and put them into assembly models of the conveyors we're designing."

With a huge amount of legacy data in AutoCAD format, a critical selection criteria for the new system was compatibility with AutoCAD. Beyond that, Martin designers wanted a solid modeler that was easy to use. Solid Edge was the answer.

Since acquiring the software, the division has embarked on the huge task of converting every product in its catalog, now in 2-D AutoCAD format, to solid models. In spite of the modeling efficiencies provided by Solid Edge, the conversion is a long process. But company officials are confident that the effort will pay off in the long run. "Solid Edge allows you to draw something only once," says Malek. "You make changes and you get a new part. It will save a great deal of time." After all existing parts are available as Solid Edge models, Solid Edge will become the division's design tool as well, for both individual parts and assemblies.


Flexible pc-board seal simplifies sensor connection

Weinheim, Germany--Obtaining a signal from a sensor within a closed vessel can be quite a problem, particularly if the vessel contains a medium under pressure. Apart from any seals needed in assembly or mounting, the wires carrying power to the sensor and the signal from it must also be sealed at the interface. The fitting of such seals can be quite labor-intensive, because wires must be connected on both sides of the sealed lead-through connector.

In a joint development project with Bosch, Freudenberg has produced a flexible circuit board with integral molded-on rubber seals. The electrically conductive foil on the circuit board consists of a flexible polyimide-copper compound. An elastomer seal vulcanized to the board provides the sealing function.

Bosch fit the new pc-board/seal combination in radial-piston distributor pumps fitted to the latest injection diesel engines. In the housing, which is filled with diesel fuel, a magneto-resistive sensor samples a coded disk, and passes its signal via the flexible circuit board to the external control unit. The circuit board carries five tracks for sensor excitation and signal transmission.

Freudenberg officials say the technique saves on assembly, component inventory, and quality inspection. With a specified temperature range of -40 to 150C at pressures up to 30 bar, the product is compatible with applications involving a variety of fuels, oils, greases, and brake fluids.


Stickier wicket, what?

Anyone who has tried to remove a bumper sticker may not believe it, but adhesion is a problem for materials researchers. Many materials require special coatings for protection from wear and corrosion. But often there is a problem with getting the coatings to adhere tightly. Los Alamos researchers have developed a method that produces highly adherent layers of common coatings such as metal oxides, plus a diamond-like carbon coating. The method uses a plasma that roots itself in the substrate, creating a graded coating that provides excellent resistance against delamination. The technique is more environmentally friendly than many methods currently in use, and allows creation of coating-substrate combinations that are not currently feasible. The method can be applied in the manufacturing of such things as automobile parts, machine tools, and prosthetics.

For more information contact Kathy DeLucas at (505) 665-9201 or e-mail duke@lanl.gov

Washington Beat

Washington Beat

Engineering societies support
doubling Federal R&D budget

The federal government's investment in R&D must double over the next 10 years. That's the core of a joint statement that a coalition of more than 100 engineering, mathematical, and science societies has taken to Washington. The groups, including the American Society of Mechanical Engineers (ASME), got some support on Capitol Hill. Senators Phil Gramm of Texas and Joseph Lieberman of Connecticut introduced a bill titled the National Research and Investment Act of 1998. It would double federal funding at several government and civilian research facilities. Prior to 1978, federal money consistently accounted for more than half of all U.S. R&D funding. The share dropped to 33.6% last year, the lowest level since tracking began in 1953. "The Federal government cannot let its contribution to the effort shrink any further," argues ASME President-nominee Winfred M. Phillips. "Investment in research provides the building blocks for our nation's competitive abilities," he adds.

X-33 successfully completes critical design review

The X-33, flagship vehicle in NASA's Space Transportation Technology Enterprise, passed a comprehensive design review with flying colors. The vehicle now has the go ahead for fabrication and assembly of all remaining components. The X-33 is a sub-scale prototype of a commercially developed, reusable launch vehicle planned for development after the turn of the century. During the five-day review by government and industry representatives, program officials announced the resolution of several issues that arose earlier this year. Questions had been raised regarding the vehicle's weight and aerodynamic stability and control. The X-33 team reduced the weight of the vehicle, modified the design of its canted and vertical fins, and decided to use densified propellants to carry additional fuel. The first arrival of a major component at the X-33 assembly facility in Palmdale, CA, is scheduled for January. It will be the aluminum liquid-oxygen tank from Lockheed Martin Michoud in Louisiana. NASA has scheduled as many as 15 test flights for the X-33 beginning in July 1999. Launched vertically, it will fly up to 15 times the speed of sound at altitudes approaching 60 miles.


Standard links microprocessors with multitude of transducers

With the burst of innovation in sensors and actuators, an abundance of different control networks has sprung up. Unfortunately for design engineers, transducer manufacturers, who now number about 3,000, have tended to favor widely different links to microcomputers. Now, the Institute of Electrical and Electronics Engineers has approved a new interface standard developed by the National Institute of Standards and Technology. The digital guideline (IEEE-1451.2) at last provides a common "smart" link between transducers and microprocessors designed for control networks.


New subs, mines will dominate undersea warfare

Quieter submarines and more sophisticated sea mines will make undersea warfare even more lethal in the future. So predicts the Committee on Technology for Future Naval Forces, a unit of the National Research Council. "The submarine threat will increase significantly--perhaps even dramatically--in the 21st century," the panel reports. This increase is being fueled by the proliferation of advanced submarine quieting, sensors, and processing technologies. However, the experts foresee a 10- to 15-dB improvement in passive antisubmarine sonar "in the near term," with an additional 10 to 20 dB before 2035. Such gains, it says, should more than offset the anticipated quieting of future submarines. Networks of unmanned sensor platforms will be needed under water and in space. Engineers also will be called upon to design small undersea vehicles or bottom-crawling devices that can detect and destroy new breeds of "smart" mines. The panel suggests the launching of smaller, lighter countermeasure ships.


Hybrid computer could simplify design of control systems

A hybrid computer that can "learn" 10 times faster than conventional neural networks promises to make life easier for designers of complex systems, such as real-time controls. Called the Fuzzy Cerebellar Model Arithmetic Computer (CMAC), it is the result of research by Intelligent Automation Inc., Rockville, MD. Working with Lockheed Martin, the firm used CMAC technology to develop a system that cancels machine vibrations, enabling machine tools to cut faster and more accurately. Common neural networks were found to be too slow to adapt to such rapidly changing conditions. Also under development: a scanning-probe microscope that uses Fuzzy CMAC to rapidly learn characteristics of a sample as it scans. The Ballistic Missile Defense Organization, seeking quicker means of locking weapons onto targets, funded original research into Fuzzy CMAC.