Engineering News 8/16/99

By Design News Staff -- Design News, August 16, 1999

Robot virtually cleans up Chernobyl

Pittsburgh-The robot, Pioneer, recently flew to Ukraine to begin analyzing the decaying cement and steel sarcophagus covering the failed Chernobyl reactor (see Design News 3/2/98, p. 98). The sarcophagus houses a depository of radioactive fuel, rubble, and dust, note Pioneer team researchers. Rain is seeping into the reactor and draining through radioactive material into ground water. If the sarcophagus is not repaired as planned, these officials say it could collapse, spreading hazardous radioactive dust into the atmosphere potentially causing another severe accident at the site.

The robot, developed by a team of experts from the U.S. government, academic, and industry organizations, comes equipped with vision and 3D mapping systems developed by Silicon Graphics Inc. (SGI, Mountain View, CA). "To stabilize the sarcophagus, we need high-fidelity imagery of the situation inside," says Jim Osborn, Pioneer team leader, Carnegie Mellon University. A photo-realistic, 3D virtual-reality map of the reactor building and sarcophagus, created using the SGI equipment, will show cracks, faults, and other signs of deterioration in the structure, as well as map the invisible hot zones the fields of radiation that exist inside.

Chernobyl staff and site contractors will use the virtual reality model of the reactor to inspect the structural damage done by the explosion and develop remediation and stabilization plans that minimize human exposure to radiation. "Virtual reality is no longer a toy," said Tim Denmeade, nuclear business manager for Redzone Robotics (Pittsburgh). "There has been an immense gap between the dream and the delivery in robotics, but…this is a dream that's time has come. The robot's vision and mapping software combined with SGI hardware represent a world's first in robotics."

Researchers expect that a Ukrainian operator in a protected room near the reactor core will use a Silicon Graphics Octane workstation to direct the robot during its mission. This offers Pioneer team members the potential to send video images and other data from the contaminated interior to another workstation housed in the Chernobyl administrative building. These researchers can direct the current mission and plan future ones. This full-scale "virtual Chernobyl" may eventually be displayed on the Web.

Machine vision masters inspection problems

By Anna Kochan, UK

Oostkamp, Belgium-Speed is the key feature of the vision technology employed by Siemens Electromechanical Components at its Belgian plant. The company must perform 100% inspection of small contacts for connectors produced at a rate of 1,600 per minute. "Because of this high speed, there is no other way to inspect such components," claims Willy Putteman, head of Siemens' control systems group.

Produced on a stamping machine into which two bands of metal are continuously fed, the contacts measure 1.5 3 0.5 cm. Once stamped, the contacts remain attached to their band. Before passing into the vision station, a jet of compressed air removes any oil and dust generated during the stamping processing. Guiding plates then feed the bands, through the vision station at a speed of 7 m/min.

Within the enclosed vision station, each band of contacts is simultaneously viewed by two cameras, one looking vertically, the other looking horizontally. The contacts are illuminated by stroboscopic lighting which holds the image stationary for a 7 msec interval.

The vision software that Siemens selected for this application was developed by Minnesota-based PPT Vision. "I chose it because of the speed," comments Putteman. "I have never seen a vision system so fast." Because the graphical user interface is icon-based, the software is also easy to configure, claims Carel van de Beek, sales & marketing manager of Simac Masic, the company that supplied the PPT software. "You don't need to have any knowledge of a computer language to set up a vision application. You just need to be familiar with Windows," he claims.

During the 75 msec cycle time of the contact inspection application, the vision system checks 32 parameters, including dimensions and shapes. For shape verification, the software matches the image "seen" by the camera against a stored pre-programmed perfect image. An acceptable level of variation is also programmed into the cycle.

Defective contacts are cut from the band by a mechanical device as it leaves the station. Failure types are also monitored. The system stops the machine and alerts an operator should the same type of defect occur at a pre-programmed frequency.

  Siemens operates the system 24 hours a day, six days a week, apart from the occasional need to dust the camera lenses.

GPS goes great guns

By Rick DeMeis, Senior Editor

Anaheim, CA-The Navy will receive its first GPS system that will be shot out of a 5-inch deck gun on a rocket-assisted projectile. During firing, the GPS Projectile Receiver, developed by Interstate Electronics Corp. (IEC), must withstand more than 12,500g longitudinally and 2,000g laterally (from balloting lateral shocks from spinning and traveling from breach to barrel exit) during firing. In as few as six seconds, the unit acquires encrypted signals from up to eight satellites. Tracking these, it will obtain stabilized navigation measurements from at least four satellites in a high-jamming (about 42 dB jam-to-signal) environment, thanks to anti-jam signal processing. Projectile software then couples data from several GPS navigation fixes with data from a 6-DOF (degree of freedom) inertial sensor for guidance to the target area, where greater jamming could overcome anti-jam features, precluding GPS-only guidance.

Other key technologies, says IEC Director of Business Development Jim Grace, are the silicon-based, proprietary-packaged, micromachined shock-and vibration-resistant inertial sensor; and processor integration. The projectiles must have a storage life of 20 years and cannot be powered up before firing. Here, processor and signal-acquisition code allows for activation and quickly processing GPS signals.

Celebrate National Inventors' Month!

Since August is National Inventors' Month, here's an ABC list of some of our favorite patent awardees:

Airbag: Allen Breed
Blender: Stephen Poplawski
Computer mouse: Douglas C. Engelbart
Digital fax: Robert Wernikoff
8-track tape player: Bernard Cousino
FM radio: Edwin Armstrong
Golf tee: Dr. William Lowell
Hot dog roller cooker: Calvin MacCracken
Intermittent windshield wiper: Robert Kearns
Jacuzzi whirlpool: Candido and Roy Jacuzzi
Koosh Ball:Scott Stillinger
Laser:GordonGould
Microwave cookware: Stanley Mason
Nuclear reactor: Enrico Fermi and Leo Szilard
Outboard motor: Ole Evinrude
Pop top can: Ermal Fraze
Quartz timers: George Pierce and Walter Cady
Radio: Guglielmo Marconi
Snowboard: Tim Sims
Traffic light: Garrett Morgan
Velcro: George de Mestral
Waterbed: Charlie Hall
Xerography: Chester Carlson
Zipper: Whitcomb Judston

Customized ball screw rolls just in time

Gloucestershire, England-Lucas Varity manufactures automotive parts. They run their production line 24 hours a day. When a ball screw on a 2-axis drilling machine became damaged, they were facing a disaster. It was going to be weeks before the original machine manufacturer got them a replacement. So they contacted Thomson IBL (Barnstaple, England), which specializes in custom-made ball screws. Engineers at Lucas sent the damaged unit to Thomson IBL for evaluation. To make repairs, Thomson could do one of three things. They could either strip, clean, and furnish the original device with new balls; regrind the shafts and manufacture new nuts to suit; or completely remanufacture a new unit. In this case, the actuator was beyond repair. Thomson engineers had to reverse engineer the ball screw so it would fit exactly into the machine from which it was taken.

Thomson quoted Lucas three days for a completely precision-ground replacement unit. They worked round the clock, physically walking the job through every stage of production. The actual product was completed and delivered within two days.

"Thomson IBL helped us out of a very big hole," says Steve French, maintenance manager for Lucas. "Their service and response was excellent. They quoted a three-day turnaround, which we thought was fantastic. Then they actually delivered in two, which was brilliant."

Invention Trivialized

Q: During the 1940s, General Electric was asked to invent a cheap substitute for rubber. Engineer James Wright came up with a stretchy, bouncy material, but it wasn't useful industrially.

What was it?

Test drive your next automation system

Madison Heights, MI-It looks like the bridge of the Starship Enterprise, but the Sensor-Connectivity Center here serves a more down-to-earth purpose. The facility is a state-of-the-art automation demonstration and training center, a place where design engineers can literally test prospective systems.

Put together by automation reseller MC², TURCK, Banner Engineering, InterlinkBT (all three Minneapolis, MN), Phoenix Contact (Harrisburg, PA), and ABB Control (Wichita Falls, TX), the center was originally aimed at serving automotive manufacturers in the Detroit area. Now, designers from many industries are using the center to evaluate sensor, control, and network combinations.

Just like on Star Trek, the heart of the facility is the "bridge" that contains the PCs that run the center. This is surrounded by backlit interactive wall panels that house the latest products and allow engineers to operate sensors, PC control concepts, and device-level buses. The panels contain: sensors; flow monitors; cordsets; networks and cabling; termination products; power supplies; and safety products.

And that's not all according to Gerry Weimer, MC² vice president of sales, "Users can bring their parts to us to solve specific sensing problems, and at the same time, visit a complete control solution. They can 'test drive' their own automation solutions, and with the help of our application engineers, determine the products and services that meet their needs."

Bus drivers. The center supports three major open fieldbuses: DeviceNet^TM, PROFIBUS^TM, and Interbus^TM. Murray Death, president of InterlinkBT, notes, "Most engineers do not get to personally evaluate a fieldbus before they make the decision to implement the bus. They can now choose from bus products that best match their application with bus benefits.

But users are the ultimate judges. Seeing the facility as a ready-to-run laboratory, Dean Schlitt, assistant controls manager at Comau North America (Auburn Hills, MI) likes "the high-tech atmosphere to asses new concepts. It helps us to evaluate the pros and cons of components."

Dennis Tencza, a senior electrical engineer at Robomatiks (Chesterfield, MI), says, "The center is like a realistic catalog. I like to go in and try out sensors. And they have devices that aren't on the market yet." He adds, " You don't understand all aspects of a product unless you see it directly hooked up. And we've even taken assemblies in and tried them out on their bench."

New controller aimed at chip makers

Richmond, CA-Joining other motion- control suppliers that have jumped onto the network bandwagon, Berkeley Process Control has introduced a new network-based motion and machine controller. Called Xtreme Control Bxi, the eight-axis controller is targeted at the semiconductor industry and is in Beta test at a number of first-tier suppliers.

Although the company's existing controls have used Ethernet for five years, the main difference with this product is that the I/O system is now on Ethernet. That makes a big difference in wafer-handling equipment, for example, that involves several robots. "In the past, one robot wouldn't know what another was doing, so you can just imagine the associated delays built into the process to avoid conflicts," says Paul Sagues, president of Berkeley. "Now, individual machines can operate in sync."

A noteworthy feature of the controller is its snug package. At just 13 inches deep, it's one tenth the volume of the model it replaces, says the company. Berkeley unveiled the product at the Hannover Fair in Germany last April. "Engineers were coming up to us and saying, 'You did all that in one box? That's amazing,'" says Sagues.

The box itself contains an eight-axis motion controller and six servo drives. Since a network is an extension of a PC's backplane, all communications take place inside the box. Only a single cable is required and it's designed to move more data, faster.

Sagues explains the company's rationale for converting to Ethernet: "We maintain that PC and controls technology are two very different things. Due to the breakneck pace of innovation in the PC environment, we don't think customers should have to make a commitment to a specific PC technology when it comes to controls. Even the fast-paced semiconductor industry expects to get 10 years out of a machine, but they can't buy a one-year-old PC! We maintain that the controls should reflect the stability of the design, and so we make them plug-replaceable. Ethernet is the common element that ties the controls and the PC together."

Performance and features notwithstanding, the most radical aspect of the Bxi controller is its price tag. At ¹¤7^th the price of the controller it replaces, it puts Berkeley into a competitive position with other suppliers of standalone controllers. "It's the first time we have designed a product and made low price a major priority from the outset," says Sagues. "I think engineers will agree that we have met that goal."

Computer Technology Solutions tackles interoperability

Detroit-Engineers from software developers Altair, Ashlar, Baystate Technologies, CoCreate, Spatial Technology, and Unigraphics Solutions will tackle the issue of interoperability during a special panel discussion September 15, 1999 at the Computer Technology Solutions (formerly Autofact) show in Detroit. Design News Chief Editor Paul E. Teague will moderate the panel discussion.

Interoperability, the ability to swap files and data among different software packages is one of the hottest topics among engineers using CAD and other engineering software, notes Teague. "While engineers are blessed with a myriad of different packages to streamline the various tasks in the design process, they want to ensure they can move data from, say, a CAD system to a finite element analysis system without losing critical features or getting bogged down in the process," he adds.

Participants in the panel discussion will explain how their products help accomplish the data transfer, and describe examples of the technology in action. Among the interoperability enhancers panelists will highlight:

Solid modeling kernals

• Technology for remote collaboration

• Standard translators

The panel discussion will expand upon the content of a special supplement Design News will publish on the subject with its September 6, 1999 issue.

Metal powder association names design award winners

Vancouver, BC-The products: sea-going tankers, softball bats, watches, jig saws, cellular phones, backhoes, printers, pumps, recycling machines, and auto engines. The materials: steel, stainless steel, copper, nickel-silver, high-speed steel, nickel-based superalloy, and titanium alloy powders. Put them together and what have you got? The winning combinations for companies that entered the Metal Powder Industries' 1999 P/M Design Competition.

Ferrous Grand Prize Powder metal (P/M) balancer gears with a 36.25° helix angle that replaced ductile cast iron at a significant cost savings won this year. Made by Stackpole Ltd. (Mississauga, Ontario) for DaimlerChrysler, the complex parts, a balancer drive gear and driven gear, operate at up to 13,000 rpm (twice the crankshaft speed) in a Chrysler 2.4l engine. The AGMA Class 8/9 gears are selectively densified on the flanks to 7.8 g/cm³. The core regions do not experience the high stresses found near the tooth surface and remain at 7.0 g/cm³. Parts are vacuum carburized to produce an accurately controlled case on the critical tooth flank surface. Gears are hardened to 70 HRA, and the case is controlled to HV500 minimum at 0.200 mm (0.008 inch) depth. Mechanical properties include: minimum ultimate tensile strength of 862 MPa (125,000 psi) and a minimum yield strength of 827 MPa (120,000 psi).

Nonferrous Grand Prize P/M nickel-silver spindles produced by FMS Corp., Powder Metal Div. (Minneapolis), used in industrial thermal printers won the Nonferrous Grand Prize. Fabricated from MPIF CNZ-1818-17 material, the parts have a minimum yield strength of 117 MPa (17,000 psi), an ultimate tensile strength of 234 MPa (34,000 psi), an 11% elongation, and an unnotched Charpy impact strength of 33J (24 ft-lbf). The spindle body with three splines (counterbore, tapered end, and hub) is sized to 0.0127-mm diametrical tolerances. The spindle body and flanges are assembled in two ways: one assembly drives the printer take-up reel, while the other, including the encoder disk, meters the correct amount of printer ribbon to be dispensed. Replacing a machined aluminum extrusion, the net-shape P/M spindles resulted in a 70% cost savings.

Stainless Steel Grand Prize A stainless-steel, AGMA Class 7 output gear used as an actuator in an automobile engine manifold walked away with the Stainless Grand Prize. Made by Keystone Powdered Metal Co. (St. Marys, PA) for Eaton Corp., the net-shape part, made from MPIF SS-304 N1-30 powder, has an inside diameter of 4.80-4.85 mm (0.188 -0.190 inch). Fabricated to a minimum density of 6.4 g/cm³, the component has a typical ultimate tensile strength of 296 MPa (43,000 psi), minimum yield strength of 207 MPa (30,000 psi), and a 61 HRB apparent hardness. The P/M part replaced a hobbed steel part, once again offering significant costs savings.

Metal Injection Molding Grand Prize A 17-4PH stainless steel P/M spool and stem tube used in a shower pressure-balancing valve won the Metal Injection Molding (MIM) Grand Prize. Made by Carpenter-Parmatech (Petaluma, CA) for Moen Inc., the spool and stem tube work together. As water pressure fluctuates, the spool moves back and forth inside the stem tube, porting precise flows of hot and cold water, to keep the temperature constant. Fabricated to a density of 7.63 g/cm³, the MIM parts have an ultimate tensile strength of 862 MPa (125,000 psi) and a yield strength of 689 MPa (100,000 psi). The spool diameters and stem tube bores have tolerances of 60.00254 mm (60.0001 inch) and 60.00635 mm (60.00025 inch), respectively. The MIM parts replaced a screw-machined spool containing a plastic insert.

Advanced Particulate Materials Grand Prize A P/M titanium alloy outer shell for a high-performance softball bat won the Advanced Particulate Materials Grand Prize. Made by Dynamet Technology (Burlington, MA) for Worth Inc., the 343 x 57 mm (13.5 x 2.25 inch) shell is formed by cold isostatic pressing, high-temperature vacuum sintering, and hot isostatic pressing. The design maintains the shell at 1.27 mm (0.05 inch) 60.127 mm (0.005 inch). The shell is assembled to an aluminum alloy frame that undergoes standard finishing to add a knob and end cap and graphics. Surface conditioning and cutting to length are the only secondary operations required. The P/M shell has an ultimate tensile strength of 1,034 MPa (150,000 psi), a yield strength of 930 MPa (135,000 psi), a 12% elongation, and a density of 4.54 g/cm³. Use of P/M provides a cost savings of about 50% compared to standard titanium alloy bats.

Overseas Grand Prize A fuel-valve nozzle for two-stroke marine diesel engines won the Overseas Grand Prize. Bodycote Powdermet AB (Surahammer, Sweden) produced the nozzle from nickel-base superalloy powder for Man B&W Diesel A/S. A hot-isostatic, pressed preform is machined to final shape by Man B&W. The nozzle atomizes 120C (248F) heavy fuel oil injected by the valves with an injection pressure of 600-800 bar. Maximum surface temperature of the nozzle during operation can reach 500-650C (932-1,202F). The nozzle has a yield strength of 900 MPa (130,000 psi) and a tensile strength of 1,100 MPa (160,000 psi). P/M replaced cast cobalt to give the part higher wear and corrosion resistance. The diesel engines run at 94-104 rpm in tankers, large ships, and fishing trawlers

How to improve P/M steel machinability

Carmel, IN-Machinability of powder metal (P/M) steels does not equal that of wrought steels of similar composition. The reason: the inherent P/M properties of interconnected porosity and heterogeneous microstructure.

The most significant effect of this revelation on cutting tools is the interruption of force on the tool when a pore is intercepted. The action of small impacts on the cutting edge increases tool failure when compared to a constant-force cutting action.

Porosity also:

Results in an increase in temperature in the cutting zone, because it reduces the thermal conductivity of the material, accelerating tool wear.

• Allows absorption of cutting oil, minimizing boundary lubrication.

• Contributes to the inclusion level in P/M by providing areas for oxides to form during sinter and heat-treat operations.

• Allows carbides and divorced Pearle to form, if the sintering process is not rigidly controlled.

All is not lost, however. The machinability of P/M steel can be enhanced by the use of additives such as manganese sulfide and boron nitride, according to Howard Ferguson, director-technology at the Metal Powder Products' (MPP) Technical Resource Center. Ferguson lists these other measures to take:

Machine between a pre-sinter and full-sinter operation.

• Apply a post-sinter anneal to initiate spheroidzation.

• Modify the cooling rate from the sinter temperature.

• Use warm compaction to a high level of green density and green strength to allow parts to be machined prior to sintering.

• Employ resin impregnation after sintering.

In an attempt to relate machinability to mechanical properties, MPP ran a series of tests to correlate drilling force and the number of holes drilled to hardness. Some conclusions drawn from the ratings are that machinability:

Increases with a decrease in carbon content.

• Is reduced by alloy additions of copper and nickel.

• Decreases with increases in apparent hardness over HRB 70.

• Is improved by MnS additions (0-0.5% optimum).

• Is not significantly affected by density, although increasing porosity increases temperature and reduces drill life.

• Is improved most significantly by resin impregnation.

You can find out more about the machinability values uncovered in the MPP tests by contacting Ferguson at (888) 359-9994 x31.

POWER METAL STEEL MACHINABILITY RATING
Material	Rating
FD-0208	5
FN-0208	18
FC-0208	22
FL-4605	24
FL-4205	35
FD-0405	44
FD-0208+.5MnS-E	55
FD-0405+.5MnS-E	66
AISI 1045 (BASELINE MATERIAL)	100
FL-4405	105
FLN-4205	110
FLN-4205+.5MnS	114
FN-0205	146
FD-0205	153
F-0008	157
FC-0205	160
FC-0208+.5MnS	168
FL-4205+.5MnS	171
F-0005	177
FN-0208+.5MnS	181
FL-4205+.5MnS	184
FC-0205+.5MnS	201
FD-0205+.5MnS	220
FN-0205+.5MnS	220
F-0008+.5MnS	222
F-0005+.5MnS	263
FC-0208+IMP	286
FC-0208+.5MnS+IMP	305
FN-0208+IMP	310
F-0008+IMP	317
FC-0205+IMP	328
Machinability of P/M steels can be determined by measuring the number of holes that can be drilled to hardness. For the measurement results shown in this table, the P/M steels were compared to wrought AISI 1045 steel in the normalized condition. A value of 100 was established for the 1045 steel; P/M steels more machinable (greater number of holes drilled) have a rating greater than 100, while P/M steels with a machinability rating less than 100 have a corresponding poorer machinability.

Insert design gives storage-system door added versatility

Woburn, MA-So you think you have a tough design problem. Then consider this one:

Develop a door to customize a mass-storage system that works in any OEM environment.

• Include vents that remain horizontal, whether the door is used in a horizontal rack or vertical tower system.

• Create a single part that can accept multiple configurations and also is cost-competitive in low-volume production.

That's the scenario Winchester Systems Inc., a maker of high-performance computer peripherals, faced when it decided to add a softer commercial look to its FlashDisk RAID disk array mass-storage system. The new look had to be compatible in a specific OEM environment, yet had to work in a rack-mounted horizontal and a tower or vertical orientation.

"We needed to have plastic inserts that would allow us to tailor the FlashDisk to blend with accompanying OEM equipment," explains Jerry Namery, Winchester Systems president. "This would position us to expand our OEM business."

Winchester challenged Mack Design (West Henrietta, NY), a subsidiary of the Mack Group Inc. (Arlington, VT), to come up with a solution. The division employs 16 people12 of them engineers.

"Mack Design came back to us with a creative proposal that not only accomplished our goals, but stayed within our budget," Namery says.

"The project was low-volume, so a full-blown plastic part requiring expensive tooling was out of the question," comments Ed Horeth, Mack Design project leader. "The door had to have vents that remained horizontal no matter if it was installed in a rack or tower system. And the digital read-out on the controller had to be viewable with the door closed."

Within two months, Horeth and his team designed a 19 x 7-inch metal door with lock that holds three 5¼-inch-sq inserts with horizontal vents. The inserts are molded of ABS/polycarbonate resin on an aluminum tool.

"The beauty of the design is that the inserts can be removed and rotated 90 degrees to maintain horizontal venting in any position," Horeth adds. "We also designed the inserts to pocket an acrylic window for viewing the digital read-out on the controller. And, when they need a wider window to view two controllers in one system, you can use a larger piece of acrylic, all with the same plastic insert."

Mack Design turned over the door design to its sister operation, Mack Technologies (Westford, MA), to produce and assemble the prototypes.

The result: "We are going to market shortly with the custom FlashDisk door design," Namery states. Production is already underway on the newly designed doors.

A quest for savings

Davis, CA-Robotic developments are popping up everywhere lately land, space, and now sea. The past few weeks have brought news of developments in Japan where robotic technology is helping the medical industry, and then there's the Chernobyl robot (see page 26). Now, ALSTOM Automation Schilling Robotics, a global supplier of teleoperated subsea systems, is working on Quest, a turnkey, electric work-class underwater remotely operated vehicle (ROV) system that will be available in March 2000.

Schilling Robotics has enlisted the help of Paragon Innovations (Richardson, TX), a provider of outsourced systems design and development services, for the development of several embedded systems components.

"Unlike many outsourcing companies, Paragon Innovations knows how to take a concept and turn it into a design and is capable of seeing it through the manufacturing stage," says Carroll Perkins, chief electrical engineer at Schilling Robotics. "We have used six outsourcing firms this past year, and Paragon Innovations is at the top of the list."

Based on a set of simplified, integrated subsystems for propulsion, control, and communication, the ALSTOM ROV is targeted at lowering the cost of owning and operating a work-class ROV.

This particular project includes technologies from Dallas Semiconductor, International Rectifier, and Texas Instruments. The technologies incorporate Dallas Semiconductor's 1-Wire^®, power components, and digital signal processing.

For Quest, Schilling Robotics is also developing the Remote Systems Engine, a set of integrated subsystems (including propulsion, control, and communication) for general use in underwater remotely operated systems.

According to the company, the ROV delivers equivalent performance to current work-class systems, but is smaller and lighter and can easily be configured for a wide range of functions. The system's high efficiency allows a reduced umbilical cross section and weight, resulting in a smaller deck footprint and reduced overall system weight. All subsea components are rated for operation at sea water depths to a minimum of 3,500m.

System Specifications

• Payload capacity in sea water: 150 kg

• Electrical input: nominal 460V ac,3-phase, 60 Hz

Quest components

• ROV with seven 7.5-kW electric thrusters.

• Approximate ROV dimensions are 1.2 x 1.5 x 2.25m, and approximate weight is 2,000 kg (4,410 lb).

• Self-contained surface and subsea equipment for electrical power distribution, conversion, and management.

• Standard suite of accessories (sensors and other instruments), including a color CCD camera and sensor pack for attitude, heading, depth, altitude, and ground speed (relative to bottom).

• Fiber-optic based communication network with 90 simultaneous serial channels and 12 simultaneous composite video channels.

• Single connector/cable design for all accessories and telemetry equipment.

• Electric actuators with position feedback for performing a range of positioning tasks.

• Lightweight launch and recovery system (LARS) and standard steel-armored umbilical.

To design for luxury, work from the ground up

Middlebury, IN-"We're the Saturn of the RV world," says Henry Spilko, drafting supervisor for Jayco Inc., a privately-owned manufacturer of recreational vehicles. To launch one of its newest product lines, the Heritage folding camper, the company recently built a completely new manufacturing facility, including equipment. Jayco calls this designing luxury recreation from the ground up.

To help with this massive undertaking, Jayco used ANVIL-5000 and ANVIL EXPRESS by Manufacturing and Consulting Services Inc. (MCS, Scottsdale, AZ).

Heritage is a new line of wide luxury folding campers. Engineering challenges included a 50% part reduction from previous models and a one-piece, seamless ABS plastic roof.

Not only did Jayco engineers use ANVIL products to create models of the camper, but they also used the soft-ware to draw complete three-dimensional models of all the manufacturing equipment such as an automatic palette return conveyer, automatic drilling fixtures, unit carriages to move the trailer along, wire harness assembly boards, and other mechanical material handling devices.

To design the product parts, engineers started with Heritage's floor plan. Every trailer or vehicle has a distinct footprint that outlines where features will be placed. Jayco's design engineers worked hand-in-hand with the Heritage product manager to design all of the required appointments. Most of Heritage's features were so unique that they had to be designed from scratch rather than from existing part files. "We literally started with the ground," said Spilko, "because the Heritage was start to finish a new product. We designed the frames, floor, walls, cabinets, roof, interior, exterior, graphics, and all of the options from zero."

Spilko and his team are also responsible for maintaining design standards that correspond to the level of product. Entry level has one set of standards, luxury another.

After creating the 3D models, Spilko sent them to a group of engineers in Jayco's manufacturing process-engineering department, who created 3D plant layouts as well as drawings for equipment tooling and fixtures. Using ANVIL, engineers simulated a Heritage production line on PCs to determine the points of use for each piece of equipment as well as part consumption. With this information, they designed the building's layout for optimum efficiency.

Jayco engineers developed a full 3D model of a Heritage unit in ANVIL. They also used ANVIL to design all the equipment to produce the folding camper and simulate the manufacturing process prior to building the plant.

Because of the many new features, management decided not to go directly to production. Instead, engineers built a prototype, constructed slowly and carefully over several weeks to prevent deviations from standards. Once approved, the system "went live." Jayco used ANVIL's Design Review module so line engineers could access the part files database and make small manufacturing modifications. Having the ability to mark up the modifications electronically was extremely efficient, says Spilko. Engineers could retrieve the latest design version at any time.

In Spilko's opinion, ANVIL was invaluable for saving the company time and money by making the Heritage creation a mostly electronic process.

Jayco runs 24 ANVIL seats on a Novell network of Pentium II Personal Computers (PCs). The company designs all its products and equipment using ANVIL. They have no other software. "We've had a 10-plus-year relationship with MCS and ANVIL. There are still many capabilities that we haven't tapped," Spilko says.

Tolerance ring shims up circular saw

West Trenton, NJ-In the consumer-driven era of mass retailers, the dual challenge for engineering is to put improved reliability into a product, while at the same time reducing cost. The highly competitive field of power tools is demanding on both counts.

In testing a 6001 ball bearing, whose outer race was bonded into a thermoset housing of a circular saw gearbox, toolmaker Ryobi had to contending with several issues. The initial design indicated that the plastic was acting as an insulator, trapping heat and causing excessive temperatures which negatively impacted bearing life.

The challenge was to add some form of thermal heat sink capability while actually reducing cost. At that point, Ryobi began to look at alternate means of retaining the ball bearing in the plastic housing while at the same time providing heat-sink capability. Enter USA Tolerance Rings, a manufacturer and distributor of tolerance rings in North America. Tolerance rings are corrugated fasteners, normally made of heat-treated carbon steel or stainless steel. The waves on the tolerance ring are springs. When compressed, these waves act like a flexible shim to ensure a tight fit between the components across all conditions.

In the case of the circular saw's bearing mount, the tips of the waves expand and contract with the changing thermal conditions and bearing bore tolerances, while the spaces between the waves allow for airflow and the subsequent reduction of heat.

There were some other benefits realized as well. The tolerance ring eliminated the guesswork over whether the adhesive had set properly in the thermoset while offering the advantages of rework capability and lower NVH levels. The overall design package allowed Ryobi to meet its reliability and cost goals for the product.

Custom cylinder improves trailer locking

Cannock, England-Raven-Trailers, a U.K-based trailer manufacturer, needed a better locking system for its so-called "sliding skeletal trailers"that is, trailers that can be extended or retracted. What they came up with is the "Lock and Go" system, which enables drivers to reduce the locking time from about 15 min to about 30 sec. Locking is required before a trailer can be extended or retracted.

Prior to the development of Lock and Go, trailer drivers needed to exit a trailer twice during extension and retraction, in order to change air lines and check pin locations. The new system enables them to automatically lock the pins and brakes by pressing a button in the cab.

The key to the system is a double-acting pneumatic cylinder with a trip mechanism built into its end cap. The cylinder and trip mechanism were custom-designed for the application by engineers at the Parker Hannifin Pneumatics Div. in Cannock, England. The trip mechanism enables Lock and Go to operate automatically. When a "king pin" is dropped into the C-shaped trip mechanism, air pressure builds up. When the pressure reaches a critical level, the cylinder actuates a mechanical wedge, which opens or closes the air supply to the brakes.

By using the trip mechanism, engineers from Raven Trailers eliminated the need for a separate roller trip valve. Prior to that, they had trouble attaching the roller trip valve to the trailer and orienting it with respect to the cylinder. Because the trip valve was also exposed to the environment, it was also more subject to wear.

By incorporating the trip mechanism in the cylinder's end cap, however, Parker Hannifin engineers eliminated those concerns, while still providing automatic access. "Because it works automatically, we've eliminated the need for drivers to get out and lock the pins in place," notes James Mayo, key account manager for Parker Hannifin. "All they need to do now is press the button and the system works by itself."