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Articles from 2003 In October


Electronics

Electronics

COSINE CORRECTORS

Helps light fill all nodes

A series of cosine correctors that attach to optical fibers is available for UV, VIS, and NIR measurements. Each of the CC-3 correctors changes the optical fiber's 25-degree angle to a 180-degree field of view. Each corrector is made of diffusing material that redistributes light. Cosine correctors can be used to measure UV-A and UV-B radiation, when coupled with a spectrometer. Ocean Optics, www.oceanoptics.com Enter 605

SENSOR TESTER

Protects against incorrect hookup

The ST-03 universal sensor tester evaluates all 2-, 3-, and 4-wire dc sensors. The palm-sized device is reportedly easy to use. Operators put sensor wires into push-button terminals and LEDs indicate the functions. The unit is protected against incorrect hookup and works with any dc capacitive, inductive, ultrasonic, or photoelectric sensor. Pepperl & Fuchs Inc.www.pepperl-fuchs.com Enter 606

WIRELESS SENSING

Connects to most control boards

The BALOGH RFID system reportedly offers affordable, general-purpose wireless sensing for industrial applications. The system includes passive data tags and transceivers, built-in or remote antennas, Ethernet or DeviceNet(R) connectivity, and part-present indicator. BALOGH requires no line of sight from tags to receiver. Error codes and alerts are part of the system package. TURCK Inc., www.turck.com Enter 607

DEVELOPMENT MODULE

Acquire, decode color images

Machine vision engineers can prototype, benchmark, and create applications quickly using the Vision 7 Development Module for LabVIEW 7 Express, the company says. The module includes a menu-driven vision assistant, which aids in experimenting with vision functions, optical character recognition, and barcode reading. The assistant generates code for LabVIEW, LabVIEW Real-Time, C, and Visual Basic. Applications include packaging, assembly, robotics, and industrial inspection. National Instruments, www.ni.com Enter 608

STACKING CONNECT MODULE

Solderless interconnections

HyperStac for Z-axis interconnections is designed for a variety of applications in harsh environments. Interconnect densities require stacking progressions for PCB efficiency. HyperStac reportedly includes a unique feature that enables a 1-mm mechanical deflection in the stack. The product is highly rated against corrosion, dry heat, temperature variation, and other environmental problems. Smiths Interconnectwww.smithsinterconnect.com Enter 609

BACK-UP POWER

Surge protection

The Back-UPS(R) series of uninterruptible power supplies includes 1,000 and 1,500V units for protection of powerful circuits. Features include more outlets, automatic voltage regulation, and long runtime. An optional extra battery pack can triple runtime capabilities for more than one PC, two large monitors, and multiple peripherals. Units USB connect and offer replaceable batteries. American Power Conversion, www.apc.com Enter 610

VERIFICATION SENSOR

Accurate part selection

The PVD Series of parts verification sensors features bright green and red job lights that provide visual cues to assemblers working the system. Reportedly ideal for multipart picking and assembly, the PVD is also used for packing, sorting, collating and error-proofing. Each unit has a sensing range up to 400 mm in diffuse mode, and up to 2m in retro-reflective mode. The PVD measures 30 x 15 mm, and includes metal housing and brackets. Banner Engineering Corp.www.bannerengineering.com Enter 611

DIGITAL OSCILOSCOPES

Robust set of trigger features

The WaveRunner(TM) 6000 digital oscilloscope series includes five models that cover bandwidths from 350 MHz to 2 GHz. The 6000 series reportedly has advanced signal capture and an easy user interface, while raising the standard of performance in bench oscilloscopes. Features include 5-ppm stability, an 8.4-inch color touchscreen, application-specific test packages, and a variety of active and passive probes. LeCroy Corp., www.lecroy.com Enter 612

Intelligent fasteners

Intelligent fasteners

Put down the screwdriver. Toss the torque wrench. Scrap the rivet guns, too. In the future, fasteners won't need any of that stuff. They'll just install themselves with the help of built-in actuators, instructions from their embedded microprocessors, and a remote control unit. This vision of the future may seem far-fetched, but you won't have long to wait for fasteners like these. Textron Fastening Systems (Troy, MI) and Telezygology (Milsons Point, Australia), this month introduced an "intelligent fastening system" that can perform tasks that dumb bolts and rivets couldn't even attempt.

With their embedded systems and actuators made from shape-memory materials, intelligent fasteners allow remote assembly via wireless devices. At the end of a product's lifecycle, they can disassemble just as easily, supporting an increasingly important need to reclaim components at the end of the product's life. These fasteners feature software that allows them to communicate with a computer network via wired or wireless connections, making it easy to capture information about fastener status and maintenance history. They can also be programmed to act as security devices, controlling access to sensitive components.

Or they could allow consumers to customize products in the field. "Once fasteners have some intelligence, there are a lot of things they can do," says Chris Kelliher, Telezygology's chairman.

Adding intelligence to fasteners could also have big implications for the design and manufacture of products in a variety of industries, including automotive, aerospace, and electronics. Seshu Seshasai, Textron's executive vice president of technology, notes that the need to provide access for assembly tools imposes its own set of design constraints-fastener locations that might be less than ideal from a strength perspective or that dictate a complex assembly sequence. "Remote assembly eliminates the need to make room for assembly tools," he says.

Many Fastener Forms

Rather than a collection of catalog products, intelligent fastening represents more of a technology framework that combines three integrated components-the mechanical fastener itself, an actuator, and the embedded system. The mechanical fastener doesn't necessarily have to differ from what engineers already use. "These are still mechanical fasteners," says Dickory Rudduck, Telezygology's director of technology. "The mechanical part can be whatever the engineer is used to dealing with." And the intelligent fastening system does in fact include models that outwardly resemble conventional threaded fasteners. But the inclusion of the actuator to lock and unlock the fastener opens up a host of new design possibilities, including many kinds of clips and sliding pins. "The key to all of them is the concept of remote actuation," says Rudduck.


Smart Bolts: One early application targeted by intelligent fastners is airbag installation. Here a Nittnol wire actuates the bolt mechanism to lock or unlock the airbag.

To make that actuation happen, intelligent fastening can employ a variety of methods. Some smart fasteners will rely on magnetic or electromagnetic actuation. One example of this type would be a magnetically actuated pin that expands a radial arrangement of finger-like clips until they engage a lip in the mating part. Other kinds of intelligent fasteners, morphing designs, will be actuated by smart materials that change shape or state with the application of stimuli such as heat or electric current. One simple implementation of these morphing fasteners is an overhang clip attached to a Nitinol wire. When heated with a bit of current to a set temperature, the wire returns to a shape that disengages the clip. According to Rudduck, various shape-memory alloys and polymers, electrostrictive materials, magentostrictive materials, and piezoelectric materials can all work in intelligent fasteners. For now, Textron and Telezygology will base their products on commercial shape-memory materials like Nitinol and a few proprietary polymers. "These materials are well out of the laboratory," Rudduck says.

The intelligent fasteners get their smarts from an embedded system that consists of a microprocessor, an energy switch, and sensors that monitor fastener status. Guided by firmware that Kelliher describes as "an operating system for fastening," this embedded system performs two important functions: It switches energy to the fastener's actuating mechanism. And it links the intelligent fasteners to larger computer networks. "The fastener becomes just another device that lives on the network," Kelliher says. This communication capability gives intelligent fasteners much of their flexibility. Using standard programming tools, users will be able to create software applications that add functionality to their array of intelligent fasteners. They might, for example, program an assembly sequence into the embedded system. Or they could add security features. Or they might gather information about fastener status and history in central database.

Like the mechanical aspects of intelligent fastening, the embedded system can take many configurations, use electronic components from different vendors, and connect to a variety of network types through wired or wireless means. "It was important that we be hardware independent," Kelliher says.

Textron and Telezygology have also developed intelligent tools for installing the smart fasteners, but these aren't your ordinary wrenches. "Usually you have to drive a fastener to torque or clamp," says Karl Schmitt, Textron's product manager for engineered assemblies. "We take that mechanism away." And the tools reflect that fact. Some of them are lock or unlock the fastener as easily as a remote control turns on a television. The most advanced installation tools are just bits of software running on a PC or handheld computer with a Bluetooth link to a nearby intelligent fastener. Rudduck recently demonstrated a couple of these digital installation tools, one that lets authorized users remove or install airbags and another that does the same for car radios. Not only did these intelligent tools provide some access control, they also guided technicians through the repair or installation process.


Digital Assembly: The tools used to assemble intelligent fasteners won't look much like traditional assembly tools. Instead, they'll be more like remote controls. Or they could simply be bits of software running on a handheld computer that communicates with the fastener via a Bluetooth card.

Intelligent Engineering

In some of the ways that matter to design engineers, these new intelligent fasteners won't differ much from today's dumb fasteners. Since they are mechanical fasteners, the joint strength considerations remain the same. "All fasteners still have to transfer a force," Seshasai says, noting that the concepts of tension, shear, and clamp load don't change with the addition of an embedded system. "Any joint strength you can achieve with a traditional fastener, you can achieve with an intelligent fastener," he says.

But in other ways, the new fasteners really do change things. On the plus side, they promise to provide additional design freedom. Seshasai points out that tool access and assembly sequence often dictate the fastener locations as much as joint strength does. "Now you can put a joint anywhere you want," he says. The intelligent fasteners, because of the built-in actuation, can also eliminate some of the tolerance or orientation issues associated with assembly tools. Cross threading could be a thing of the past.

They also shouldn't present any packaging difficulties, despite their onboard electronics. These fasteners tap into a product's existing wiring and electronics. Rudduck wryly notes that "digital commands take up far less space than an a physical tool." He believes that smart fasteners can attain much smaller sizes than conventional mechanical fasteners-in part because they overcome traditional spacing constraints and in part because smart materials will allow them to be smaller. "Smart materials will ultimately be applied on a nanotechnology level," he predicts.

Goodbye Nuts and Bolts?

For all their benefits, intelligent fasteners will pose some technical barriers-at least at first. "The biggest limitation is thermal," Rudduck says, noting that current Nitinol grades have a maximum transformation temperature of roughly 150C, low enough to interfere with the fastener's actuation in high-temperature automotive applications. "That would restrict our initial activities to inside the cabin," he says. Thermal limitation, however, should ease as new high-temperature shape memory alloys become available. "We'll be able to migrate into hotter applications as the materials evolve," he says. If left unchecked, RF interference could also plague smart fasteners. But Seshasai points out that it can be avoided with well-understood shielding methods, just as it is in other products with onboard electronics.

Finally, cost could present a problem in the wrong applications. On a fastener-to-fastener basis, the intelligent fasteners will cost two to five times as much as their dumb counterparts, Seshasai estimates. But they're not really intended as a drop-in replacement for simple fasteners that already work just fine in existing products. "We won't compete in those applications," Seshasai says. He argues intelligent fasteners will mostly find a home in new products where they can add value by performing tasks that ordinary fasteners can't. What's more, intelligent fasteners may substantially lower total costs-by simplifying assembly operations. "Intelligent fastening replaces robots and other expensive assembly tools," Kelliher says. "So it removes some of the capital intensity of manufacturing."

Even if the technical and cost barriers do disappear quickly, intelligent fastening will still have one more hurdle standing in its way-the confidence of engineers. Do the built in actuators add a new electronic failure mode to fastening? Will these fasteners unlock at the wrong time? That's the first thing that crossed Ron Weddle's mind. As the director of manufacturing technology for Cessna, Weddle had an early look at the intelligent fastening system. "Because they have an induced unlock feature, we would want to make sure that they don't unlock when you don't want them to," he says.

Nothing inspires confidence, however, like the years of rigorous testing required for aerospace applications. And Weddle doesn't rule out the fasteners for important access-panel and cowling joints given enough validation work. "They have potential," he says. For now, though, he says Cessna is only considering the new fasteners for joints inside the cabin. For example, the company is looking at them as a way to attach-and control access to-flight electronics.

Textron and Telezygology plan to take a similar tack in the beginning and move into critical joint applications only after technology proves itself. For the non-critical applications, though, Textron is ready to supply intelligent fasteners right now. "We can make them today," says Seshasai.

Senior Editor Joseph Ogando can be reached at[email protected].

Enlightenment

Enlightenment

American Power Conversion (APC) is hosting free interactive seminars on power disturbances. The power protection equipment manufacturer for IT products will educate consumers on the impact of blackouts at home and office, facts about power, as well as its products and services APC offers, such as uninterrupted power supplies (UPS), surge strips, management software, and mobile accessories. To register, go to www.apc.com for the Blackout Support Center, or call (800) 877-4080 for inquiries.

Non-Automotive CAN Ramps Up

Non-Automotive CAN Ramps Up

In the case of the CAN (controller area network) serial bus data link, a non-standard has now become a standard in fact, according to Holger Zeltwanger, managing director of CAN in Automation (CiA, www.can-cia.de), an international trade association that provides technical and marketing information, and fosters future developments. He notes that more than 50 off-the-shelf microcontrollers from over 15 chipmakers have the CAN option built in (see caption for the latest). "If it is on all of these, then it is in effect a standard for implementing a reliable data link," he notes.

"The data bus has widespread use in both U.S. and European-made cars-300 million chips this year alone in European cars (at 30 chips per car)," says Zeltwanger. And non-automotive applications in Europe are about five years ahead of the U.S., he offers. Europeans have put CAN in systems from commercial coffee brewing machines to elevators, trucks, trains, and aircraft. CAN is embedded more by machine builders in Europe, whereas in the U.S. the focus has been on communications for factory automation. "And most CAN applications don't push the speed limit," Zeltwanger adds. While its maximum data rate of 1 Mbit/sec is needed for rapid, precise pick-and-place and automotive control tasks, most uses only require 250-500 kbit/sec.

Zeltwanger views CAN today as analogous to having alphabet characters that must be formed into languages users agree on. He notes, "It needs standard integration of higher level protocols." But that said, all that users need are standard "phrases" (profiles) to get along in writing applications, much like international travelers use to make themselves understood, rather than be concerned with the complete rules of grammar. He adds that, because they are so large, automakers have specified their own languages and the CANopen language for automation was developed by users.



CAN Extended: Improved CAN flexibility and greater memory are keys to the latest PICmicro flash microcontrollers from Microchip Technology (www.microchip.com). Their scalable ECAN interface module has three software-configurable operating modes: legacy for compatibility with existing microcontrollers; enhanced with additional functions; and FIFO for sequential message storage. The single module enables multiple applications to be configured on a single node. Product Manager Greg Robinson says easier, hardware-based CAN use allows shorter development time. He adds the high voltage of hte chips' physical layer and higher bus voltage boost noise immunity for applications, such as controlling motors near high-voltage devices in medical equipment.

On the application level, users and organizations are trying agree on interfaces between protocols, as is now the case with CAN and higher speed, up to 400 Mbit/sec, FireWire. Then, for example, a profile to control hydraulics would just need its parameters changed to function with different bus protocols. "In the future we won't talk buses but profiles," Zeltwanger says. He also notes other cooperative efforts now underway, such as that headed by the U.S. National Institute of Standards and Technology (NIST, www.nist.gov) defining standards for sensors in non-automotive applications.

Know Thy Fasteners

Know Thy Fasteners

What are the biggest problems engineers have when specifying fasteners into a design? With the exception of a few engineers, most don't have a clear understanding of how bolted joints behave.

How should they consider them? They should know that a bolted joint is an integrated system of nuts and bolts. They should take into consideration clamped parts, mechanical properties of clamped parts, locking elements, tightening tools, applied tightening torque, and last but not least the person tightening the bolt.

Why is the apparent lack of knowledge a problem? If fasteners are simply used to hold a component in place such as a hose, a cable, a wire, or a lightweight sheet metal part, then for the most part there are no problems. Issues arise when fasteners fulfill a load-critical function, such as to keep the wheel from falling off the axle, to make sure the connecting rod is permanently secured to the crankshaft, or make sure the frame of tractor is fastened securely. In such cases all the parts used in the joint must be evaluated and properly laid out so that the joint and the piece of machinery it is holding together will survive both loads and the working environment's conditions. A bolt failure is often contributed to a bad fastener. There certainly are bad fasteners, but on average only one out of ten failures can be attributed to a fastener that is not mechanically sound.

What are the best strategies for overcoming those problems? Gather information. Spend as much time understanding a fastener as you do a jet engine-maybe not quite as much. An engineer should evaluate what the bolted joint has to deal with. Time can be allocated somewhere else if the fastener's function is to support something lightweight. However, if it turns out that the bolt has to deal with a great deal of pain (stress), then further research is necessary.

Do stainless steel fasteners last longer than fasteners with a protective coating or plating? That depends on the environment. Let's assume we use a plain regular unprotected steel fastener and an austenitic (300 series) stainless steel fastener on the same piece of machinery, somewhere in the Mojave desert. Both will last the same amount of time. On the other hand, if a fastener is used on a piece of machinery along the ocean shore the unprotected fastener will corrode within days whereas the stainless steel fastener will look brand new.

When should engineers use stainless steel? If a fastener is likely to be used in an air-conditioned room where the air-conditioner is on all day and night, zinc-plated fasteners will do just fine. However, seriously consider stainless steel if the same fastener is used in a room along the oceanfront with no air conditioning or the air conditioning is likely to be shut down overnight and or over the weekends. Stainless steel fasteners are certainly more costly. The most common corrosion-resistant (300 series) stainless steel fasteners have lower strength, typically about 90% of that of a grade 5 (or metric 8.8). Also, they actually may corrode internally without anybody noticing it, to the point where they fracture. Austenitic stainless fasteners are susceptible to corrosion under certain circumstances. A typical instance is the high concentration of chlorine fumes inside indoor swimming pools.

PCs & Workstations

PCs & Workstations

THEY DELETE TO COMPETE

Sun Blade 1500 Workstation. This 64-bit workstation sports the same 1 GHZ UltraSPARC IIIi processor found in Sun's higher-end mission-critical servers. To keep costs down, engineers cut the number of components by integrating the memory controller and 1Mbyte L2 cache onto the CPU, and incorporated Double Data Rate (DDR) memory instead of SDRAM, and Advanced Technology Attachment (ATA) drives. "There is some trade-off concerning cache size," says Sun Workstation Manager Brian Healy. But he adds by integrating the cache onto the die, engineers reduced memory latencies by up to four times, maintaining performance while reducing cost and complexity. In addition, this architecture has low power consumption-350W maximum vs. 670W for a Sun Blade 2000. (www.sun.com) Enter 582

DO IT YOURSELF

IBM ThinkCentre S50, M50, and A50p. Using a design for assembly and disassembly approach, IBM engineers developed an easy-access, tool-free chassis design for these products. That means users can easily remove the hard disk and memory for upgrading or servicing. Among design strategies: Cable routing is bundled out of the way for easy access to components and cable ends, and user "touch points" are colored blue for easy identification. There's also a "caddy" that surrounds the hard disk drive, locking it into place without the use of tools or screws. (www.ibm.com) Enter 583

BIG HEART

Apple Power Mac(R) G5. This personal computer has a big heart-specifically, a 64-bit processor, which Apple claims is a first for a PC. It beat out Xeon and Pentium 4 processors in a SPEC CPU 2000 benchmark test. And, it will still run 32-bit applications. The guts also include dual 2.0 GHz PowerPC G5 processors, each with an independent 1 GHz front-side bus. The electronics can build up a lot of heat, so Apple designed a proprietary computer-controlled cooling system to get rid of it. The thermal management design includes four discrete thermal zones to compartmentalize primary heat-producing components. Fans run at low speeds to keep the machine quiet. (www.apple.com) Enter 584

Software/Hardware

Software/Hardware

CAD SOFTWARE

2D to 3D CAD evolution

"Evolve to 3D" is a program added to the company's Solid Edge(R) CAD software, allowing customers to simply upgrade from 2D to 3D applications. The program also allows users to keep their 2D design integrity while changing files to 3D, the company reports. Features include a migration wizard, 2D/3D hybrid workflow, embedded design manage-ment, and a simple four-step method of upgrading to 3D. EDS PLM Solutionswww.eds.com/products/plm/ Enter 585

FLUID ANALYSIS SOFTWARE

Model, expand fluid scenarios

Fluid flow analysis software includes CAD/CAE associative capabilities and expanded analysis ability. The software reportedly allows designers to model a wider range of fluid flow scenarios than previous versions. Features include the prediction of steady and unsteady flow patterns in laminar or turbulent flows. The product supports direct data exchange with many file formats and CAD software titles. Algor Inc., www.algor.com Enter 586

3D WORKSTATION

Alternative to fixed systems

The dStation(TM) is a self-contained, portable imaging system for 3D visualization, with a ROVR(TM) large-screen, digital stereo system for field work. It is designed as is a two-channel visualization wall for display events like trade shows. The system contains two modules, each with a 1280 x 1024 projector and connections for up to eight computers. SVHS and DVD players are included. Fakespace Systems, www.fakespacesystems.com Enter 587

WEB-BASED LIFECYCLE SOFTWARE

Access product performance information

Nlighten(TM) product engineering software is a web-based application providing information about product design economics. Reportedly able to give designers insight into hidden-value improvement, Nlighten helps reduce product lifecycle costs and predict more accurate and consistent ROI numbers. Features include alerts to identify problems, quick access to historical data, and design change monitoring. Ninatek, www.ninatek.com Enter 588

RENDERING SOFTWARE

Complete digital development

Automotive designers and engineers are using total digital development products like the CAD Automotive Pack. It provides integrated rendering and visualization programs that speed the process through styling, pre-visualization, image regeneration, advanced photorealism, and integration with CAD programs' geometric databases. The product includes a library of shaders for visualizing multi-layered coatings on surfaces. Lightwork Design, www.lightwork.com Enter 589

MILLING SOFTWARE

Windows-based axis milling

Subtractive rapid prototyping devices are available in combination with VisualMill Basic CAM software, offering complete control of the milling process, the company claims. Units bundled with VisualMill include the MDX-650, MDX-500, MDX20, and MDX-15. The products are reportedly ideal for rapid prototyping, mold making, and educational purposes. Features include intuitive interface, simulation of all tool paths, 2.5- and 3-axis milling, and optional 4th and 5th axis usage. Roland DGA, www.rolanddga.com Enter 590

MODEL LIBRARY

Over 4,000 models available

SIMPLORER(R) component models are available for current customers to download. The items for the multi-domain system simulation software include over 4,000 predefined models from companies like International Rectifier, Maxwell Technologies, Analog Devices, and Infineon. Models include MOSFET, OpAmp, diodes, multiplexer, and rectifiers. Ansoft Corp., www.ansoft.com Enter 591

DRAWING SOFTWARE

Drawing product add-on

The DwgStrip tool is available for AutoCAD 2004 software. The product works like the layout tabs located at the bottom of AutoCAD's editor, but allows fast switching between open drawings. Features include indicators for drawings that are not saved, and full name and path on the tool tip when the cursor hovers over the tab. Dotsoft, www.dotsoft.com Enter 592

PRODUCT DESIGN SOFTWARE

Expand concepts to designs

Conceptual and industrial design software Pro/CONCEPT v2.0 is available for Macintosh OS X systems. The product allows designers to sketch and model in one user environment, the company says. Features include curve layouts, photo-realistic images, 3D facet models, real-time rendering, transfers to and from MCAD and collaboration systems, and a variety of formats like STL, VMRL, ProductView, OBJ, TIFF, and JPEG. PTC www.ptc.com Enter 593

CAD/CAM SOFTWARE

New redirection function for data

TopSolid 2003+ contains improvements including the performance of the integrated CAD/CAM handling of complex models and large assemblies, the company reports. When shaded models are changed, only the modified part surfaces are recalculated, saving time in many operations. Memory management for large assemblies was improved, as was collision checking and support for high-speed milling. Missler Top International Softwarewww.topsolid.com Enter 594

Ask the Search Engineer

Ask the Search Engineer

Data glow . . . Bronze bearing replacement . . . Reader corrections . . .

Dear Search Engineer: I'm trying to find a way to have data glowing through a tinted plexiglass window with the power of an LED. The font size is about 6 or 8. When a function is selected, an LED lights up. Could I use the LED to make the information glow? Could I use a fluorescent tape for this purpose?-J.R., Canada

Eh, J.R.: A simple light sanding or sandblasting on the plexiglass can even-out the light dispersion. There are also plastic filters either made or used for this purpose. Look at an instrument cluster in a low-end auto and you will see how it is done.

Dear Search Engineer: I'm looking for some plastic that can replace a porous bronze sleeve bearing. Any suggestions?- D.N., CA

Dear D.N.: First of all, great initials! I've got a couple suggestions to check out. RTP Company (www.rtpcompany.com) is a custom thermoplastic compounder that does metal replacement applications. A couple of ideas would be their Splash Lube Gold materials and PTFE-filled acetal material. Another possibility is replacing the bearings with Hycomp bearings. (www.hycompinc.com)

A couple of notes from loyal readers . . .

F.D. writes about the electrically controlled fiber optic devices in the July 7 issue . . ."While you suggested a large-scale routing system based on micro mirrors, I'd like to bring to your attention that Fibersense & Signals Inc. (www.fibersensefirst.com) provides a range of fiber optic, photonic, and electro-optic combining, switching, and routing components."

And W.W. offers this advice to D.J. on the size of a hex head also from the July 7 issue:

For both hex head cap screws and hex head bolts, the width across flats is 1.5 D where D= basic (nominal) bolt or screw diameter. For both the hex head screw and hex head bolt, the head height is 0.625 D minus 0.0 to 0.031, depending upon diameter, for hex cap screws and plus 0.0 to 0.188 for hex head bolts again depending upon diameter.

So actually the hex head bolt will have a higher head height and may be considered slightly larger but requires the same wrench for installation. Tolerances are less on the hex head cap screws. Similarly, the width across flats for both heavy hex screws and heavy hex bolts is 1.500 D plus 0.125 and the head heights are the same as indicated above for hex head screws and bolts, respectively.

Since a hex head cap screw may always be substituted for a hex head bolt but not vice versa, the design engineer should select the hex head cap screw. Even with more precise tolerances, the higher quality hex cap screw may be less expensive as most manufacturers are standardizing on the cap screw configurations. For higher strength steels, the heavy hex configuration is recommended, while for CRES and most non-ferrous applications the regular hex configuration is usually more readily available. (Source for Dimensions: ASME B18.2.1 Square and Hex Bolts and Screws)

Chrysler's cruise missile

Chrysler's cruise missile

Few would argue that the Dodge Tomahawk defies common sense. After all, who needs a motorcycle that reaches a top speed of more than 250 mph, cranks out 525 hp, and goes from 0-60 mph in 2.5 seconds? Moreover, who needs a vehicle that - if it ever reaches full-scale production - could be priced at a staggering $250,000?

Obviously, no one needs it. But the Tomahawk isn't about need, and it certainly isn't about common sense.

"My first reaction to this idea was that it didn't seem like the most intelligent use of power," says Mark Walters, the DaimlerChrysler senior designer who masterminded the construction of the highly-publicized vehicle. "But I had to admit: it is cool."

Indeed, Walters isn't the only one who thinks it's cool. Since unveiling the Dodge Tomahawk concept vehicle at the Detroit Auto Show in January, Chrysler Group has been inundated with requests from interested parties who want to sit on, ride, or buy the vehicle.

"We get people calling all the time and saying, 'I want to buy one, and I've got cash. How much do you want for it?'" Walters says.

Like the Dodge Viper of more than a decade ago, the Tomahawk has attracted the attention of movie stars and celebrities, most of whom hope that some of its star quality will rub off on them. At one of last January's Super Bowl parties in New Orleans, the Tomahawk appeared with the likes of "Joe Millionaire," Jane Seymour, and others. It then traveled to Burbank, California for a visit with motorcycle buff Jay Leno, who wanted to see the four-wheel motorcycle do a few burnouts.

In that sense, the Tomahawk is already fulfilling its purpose. The company isn't hiding the fact that the vehicle is mostly about image, and serves mainly as a message to consumers that DaimlerChrysler is a company that isn't big on conventional boundaries. "This is a bold-faced slap against mediocrity," said Senior Vice President of Design, Trevor Creed, in a prepared statement. "Tomahawk is a scintillating example of what creative minds can do when given the opportunity to run free."


At 8.3 liters, the Viper engine was about five times the size of a big motorcycle engine, leaving Tomahawk designers with a huge packaging dilemma.

Free Spirits Lead to Creative Concepts

Indeed, the company's willingness to let creative minds run free is the very essence of the Tomahawk.

The idea originated with two DaimlerChrysler employees who also happened to be motorcycle enthusiasts. "They had this idea to build a Viper-powered bike," Walters recalls. "They wanted to take the V-10 Viper engine and put it in an existing motorcycle chassis, but never found the time to do it because they both have families."

The two employees-clay modeler, Bob Schroeder, and vehicle build specialist, Dave Chyz-ultimately brought their idea to Freeman Thomas, DaimlerChrysler's vice president in charge of advanced studios, who in turn took it to Walters. In discussing the idea with Walters, Thomas mentioned he had a vision for the bike inspired by the 1982 film, Tron, in which actor Jeff Bridges, trapped in a video game, rides a virtual, four-wheeled motorcycle.

Walters took the Tron concept, worked with it for a few weeks, and then pitched it to Chrysler Group Chief Operating Officer, Wolfgang Bernhard, and CEO, Dieter Zetsche. Using giant panels measuring 20-ft long and 6-ft high, Walters showed the executives the concept for the bike and the corporate marketing advantages. He explained that the Tomahawk would give DaimlerChrysler access to truck events, where truck buyers (many of whom are motorcycle enthusiasts) would line up in droves to see the 250-mph vehicle.

"Basically, we saw it as a way to crash a party," Walters recalls. "At the same time, we were hoping we could expose some of those consumers to the products that we make."

Zetsche and Bernhard quickly saw the merit in the concept. "They loved it," Walters recalls. "Much to our surprise, they told us to build it."

Mass Dilemma

Once the corporate blessing was obtained, however, the hard work began.

By the time Walters received the go-ahead, it was already May 2002, and DaimlerChrysler executives were hoping to see a finished vehicle by January 2003. That placed him approximately eight months behind the normal concept car schedule, which calls for design work to begin in early October, approximately 15 months before a vehicle's unveiling.

"The idea came up so late that the only way I could see making it happen was to move my workstation down to the fabrication area, where I could talk to the people who would be putting it together," Walters says. "Once I did that, we were literally only a few feet apart."


Handwork: In many cases, engineers say they had to do the machining of aluminum transmission parts -- held to tolerances of 0.001 inch -- by hand because of the complex curves and valleys involved.

The real dilemma facing Walters, however, was the sheer mass of the Viper engine. With a displacement of 8.3 liters, the V-10 Viper engine is more than five times larger than a big motorcycle engine on, say, a Harley-Davidson. "The worst evil of all was the physical mass," Walters recalls. "It's a lot of weight, a lot of metal, a lot of moving parts, and an awful lot of power."

For that reason, the use of the four-wheeled motorcycle concept suddenly seemed more appropriate than ever. The four wheels, Walters reasoned, would offset the extraordinary visual mass of the motor. What's more, the four wheels provided a more natural path for transferring 525 hp to the street.

"If you've ever seen a Viper do a burnout, you know that one little contact patch is not going to be enough," Walters says.

By employing twin wheels instead of one, however, Walters doubled the size of the Tomahawk's contact patch. Doing so, he says, not only helped with acceleration, but also braking.

Still, DaimlerChrysler had to deal with the engine's mass in other ways. The sheer mass of the engine loomed as a potential balance problem, especially for shorter riders moving at slow speeds. There, engineers say, the gyroscopic effect of the wheels doesn't provide balance as effectively as it does at higher speeds. As they near stop lights, for example, riders of all motorcycles typically must place their feet down on the street to balance the bike. And while that may not be a problem with a smaller bike, it was for the Tomahawk, which was nearing an ultimate weight of almost 1,400 lbs.

Their solution was to place the heaviest part of the bike - the engine - as low as possible. To accomplish that, DaimlerChrysler designers worked with engineers at RM Motorsports (Wixom, MI), builders of custom-designed race vehicles, who suggested that they use a "dry sump" engine. With the dry sump, the Viper engine could be placed lower, they said, because the oil pan would no longer be located at the bottom of the engine.

The design team created a dry sump by employing a remote oil pan, and then using a high-pressure oil pump with a scavenging stage to transport oil back and forth to the engine through pressurized lines.

By doing so, the team moved the engine down and lowered the bike's center of gravity. The lower engine, in turn, also provided riders with greater control at low speeds.

"Keeping the saddle as low to the ground as possible helps the riders," Walters says. "If they do have to use their legs at a stop light, they're not up on their toes. They can take a wider stance and gain a little leverage."

By moving the engine lower, Walters says he also left enough room for a specialized suspension system that further helps riders to deal with the motorcycle's mass. The suspension system consists of a pair of swing arms running to each of the rear wheels, and pivoting off the output shaft of the transmission. Each of the arms is connected to a spring-loaded linkage, which compresses one of the springs whenever the rider turns.

Weight, however, wasn't the only challenge wrought by the use of an 8.3-liter engine.

"Anything that makes that much power is going to generate a lot of heat," Walters says. "And you have to dissipate that heat somehow if you expect a rider to sit on it."

Dealing with Heat

To dissipate the heat, the design team scrapped the headers from the original Viper engine, and created a custom set of unequal length headers that run from the exhaust port to a "collector" that runs straight to the rear of the vehicle. By doing so, Walters eliminated the risk of burning the rider, whose knees would be close to the excessive girth of the engine.

Tomahawk's designers also wrapped the headers with a material often used to insulate turbochargers. The material, which wraps around the headers like an Ace bandage, helps eliminate the possibility of riders being burned.

Walters says that one of the biggest heat-related challenges, however, was simply cooling the engine. "A Viper uses very powerful fans and a radiator that's really big, located in a place where it gets a lot of air," Walters says. "But packaging all that onto a motorcycle would look ridiculous."

Still, engineers from RM Motorsports believed the problem could be solved. They first recommended the use of a cast aluminum fan that incorporates an alternator, thus enabling them to solve both the airflow and packaging problems in a single stroke. At the same time, the design team incorporated a pair of small radiators, measuring about 18 inches long by 8 inches high, which they placed in the "V" of the V-10 engine. Engineers arranged them in an A-frame shape and then sealed the area in a way that forces air past the radiators, to help in cooling.

Walters says that because of the short time frame, much of the engineering was of the seat-of-the-pants variety. There simply wasn't time for complex computational fluid dynamics studies on the cooling system, he says.

"We did use finite element analysis on the suspension arms," he says. "But the cooling system was a result of engineering experience more than anything else."

Custom Design

Experience was also the key element in the development of a special transmission for the Tomahawk. The need for the transmission arose partially because the Tomahawk's crankshaft runs transverse to the drive axle, but also because the gear ratios that it requires aren't available in any commercially available transmissions.

With the deadline looming just a few months ahead, engineers at RM Motorsports decided to solve the problem by making a transmission from scratch. The company's engineers mocked up a prototype using available gears and wooden parts. Then they drew up graph-paper sketches of the transmission casing, which they gave to Walters. He took the drawings to his workstation, "surfaced" the case, then provided a data CD to a vendor that milled the transmission case from a 10,000-lb, solid aluminum billet.

"Even though we were working in tolerances of a thousandth of an inch, the transmission worked right out of the box," Walters says.

At the same time, engineers at RM Motorsports worked with vendors on machining of wheels, body parts, swing arms, throttle body, and handlebars from smaller aluminum billets. In many cases, RM Motorsports engineers say they had to do the machining by hand, rather than via computer numerical control.

"Parts such as the throttle body and handlebars had complex curves and valleys, and there was no easy and fast way to do it," notes Bud Bennett, president of RM Motorsports. "It was like making a clay model, only from aluminum. We could have done it with a computer program, but it would have gone too slow."

A Chrysler Group spokesman says that the resulting prototype cost approximately $500,000 to design and build. That figure, he says, is low by comparison to most concept vehicles.

Designers of the vehicle say they really don't know how fast the resulting vehicle is.

"If it were geared properly, 250 mph would be attainable," Walters says. "But right now, it's geared for acceleration, not speed." Although the company has published top-speed figures of 400 mph, Walters says he doesn't believe, and doesn't want to know, if such speeds are possible.

The company has said, however, that the vehicle accelerates from 0-60 mph in under 2.5 seconds, and reaches to 120 mph "very, very quickly." Engineers refused to place a number on the 0-120 mph speed, however.

"I've ridden it, and it makes my 1,100-cc sport bike feel like a scooter," Walters says.

Whether the automotive giant will put the Tomahawk into production is another matter. Industry insiders expect it will.

Milestones in Motion Control

Milestones in Motion Control

Ethernet-Based Motion Networking- Using Ethernet as the basis for servodrive networking gained a major boost earlier this year when the third-generation SERCOS and PROFInet working groups proposed plans for future motion control networking. Both groups announced that standard Ethernet technology would be utilized as the physical layer for next generation versions -and compatible protocols for high, performance motion control applications. At this year's Hannover Fair, PROFIBUS International (PI,www.profibus.com)announced the beginning of development work on a high-performance, real-time solution for highly dynamic motion control applications under PROFInet called Version 3.0 IRT. This proposed solution uses standard Ethernet media, compatible protocols, and an ASIC that embeds both a switch and the protocol to guarantee real-time, deterministic performance.

Firewire Sparks New Interest- Of the three networks available as a standard on PCs -Ethernet, USB, and FireWire -the network that is least well-known is FireWire (or IEEE-1394).And in industrial circles, with Ethernet gaining momentum for factory data communications and I/O control, there is less awareness of a growing number of FireWire-based control solutions. But that level of awareness may soon change. The 1394 Trade Association, which oversees the standard and has a primary focus on computer and consumer electronics applications, is working with a coalition of industrial companies to eek a FireWire standard for machine control, including motion, vision, and I/O.

Automated Fluid Filler Shuts Off Down Time- An automated fluid packaging machine based on a new design enables users to change from one size container to another in minutes, versus hours, or even days, with a mechanical system. Beyond the obvious productivity gain and cost reduction benefits, the quick change capability enables cosmetics companies and other purveyors of product in fluid form to justify smaller production runs, thus they can continue to meet customers 'supply demands while also minimizing inventory.to read the rest of the supplement click here