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Articles from 2001 In April


LCD replaces five analog meters in pipeline device

LCD replaces five analog meters in pipeline device

San Gabriel, CA -Will Page understands that retaining some aspects of an old product design is important to a new product design.

As the chief engineer and supervisor at Tinker and Rasor, Page knew that the look of the electromechanical analog meters used in the company's pipeline inspection equipment was important to equipment operators. Interpreting information presented by the old meters was considered an important skill, so he wanted to retain their appearance. But when the company introduced a new line of portable pipeline equipment, the analog meters had to go.

Page found his solution in a customized liquid crystal display (LCD) from Crystaloid Electronics (Hudson, OH). The LCD emulates analog meters in appearance and function, but eliminates the problems associated with them.

The new meter has solid state circuitry that uses the equivalent amount of the electric power needed by the previous electromechanical meter. The LCD has no moving parts, so there is less chance of equipment failure in the down-and-dirty, rough-and-tumble world of on-site pipeline inspection. The single display module also replaces what had been five different electro-mechanical meters.

"There were a number of stock meters or displays that might have been used or adapted, but none gave us all that we were seeking," says Page. "By working with a supplier that developed their specialty to meet our needs, we now have a display that retains the appearance of our traditional analog meter."For more information about LCDs from Crystaloid Electronics: Enter 533

Robots perform in parallel

Robots perform in parallel

Austin, TX -Time is money. So it's no surprise that high throughput was one of the key goals of Mattson, a division of Steag Electronic Systems, when designing its new wafer handling system. In particular, Mattson engineers were looking for a front-end input/output handling system to its wet bench tool that had a throughput of 400 300-mm wafers per hour. Their solution? An input/output tool from Berkeley Process Control (BPC; Richmond, CA) that allows four robots to operate in parallel, thereby eliminating any down time in the process.

This front-end wafer handling system for a wet bench consists of four robots, two slides, and one aligner for a total of 14 axes. Three BXi controllers networked together oversee the operation. Normally, a controller would be required for each mechanism (7 total), plus a PC with a 2-axis motion card.

Performing certain operations at the same time can be difficult to accomplish with conventional robot control systems, which operate as a central "brain" with sub-controllers connecting on each robot and other mobile devices connected in serial fashion. A central computer sends messages to each individual sub-controller, but leaves the central controller out of the communications loop. In other words, the left hand doesn't know what the right hand is doing-making it difficult to perform multiple tasks in parallel. Although information on their status can sometimes be squeezed out of the sub-controllers through a kind of game of 20 questions, this process eats up computing resources in a big way.

However, the latest generation of controllers by Berkeley Process Control places the functionality under one brain, thereby eliminating the independent nature of individual operations. Called the BXi motion and machine controller, it is an 8-axis distributed control element that is integrated with eight servo drives and allows individual controllers to be networked together as if they were one. The entire package-measuring a compact 8.6 x 3.2 x 9.8 inches, includes a 64-bit RISC scheduling computer, 56 digital I/Os, light curtain circuitry, and e-stop circuitry with force-guided contactors.

The key to the new controller is its increased computing power (almost ten times the previous generation) and the available bandwidth of system communication pathways (100 Mbit as compared to 10 Mbit Ethernet).

Through virtually instantaneous acquisition of data from system sensors and other I/Os, and its delivery to the "brain" powered by a 64-bit microprocessor, the controller can know the position of all individual elements at any given time. In other words, the system can now "see" where it once was blind.

Wafers in this input/output handling system move between different processing stages. An R-Z-Theta input robot (1) picks wafers one at a time from the input pod and places them on the wafer aligner (2). The R-Z-Theta robot then orients the wafer for hand-off to the twist-and-rotate robot, which places it into the wafer boat on the input slide. Once the wafer is centered and aligned, the R-Z-Theta input robot (3) picks it up and orients it. The twist-and-rotate robot (4) picks up the wafer and places it into the input wafer boat (5) that is indexed by the input slide.
Events safely overlap throughout the process, which is possible through the use of the BXi controller. For example, while wafer aligning takes place, the twist-and-input robot gets into position for the handoff and completed wafers are transferred to the output wafer boat carrier.

In the input/output wafer handling system, which is a front-end to Mattson's wafer handling system, engineers networked 3 Bxi controllers, which oversee the operations of four robots, two slides, and one aligner-a total of 14 axes in all.

This constant and automatic feedback of operational data allows various tasks of the wafer handling system's ability to overlap without danger of a collision, which has an obvious impact on throughput. The ability of the controller to auto-calibrate in minutes also reduces setup time from hours or days to just minutes.

When vendors introduce new versions of their controllers, backward compatibility is always a question for design engineers. "Because it is based on the same architecture and design, the BXi controller is compatible with software written for our controllers dating back some 15 years," says BPC's Mario Lento, product specialist. "The only software tweaking required is a remapping of the internal I/O module."

For more information

Go to www.designnews.com/info or enter the number on the Reader Service Card:

BXi controllers from Berkeley Process Control: Enter551

1 basic coupling, 3 application ideas

1 basic coupling, 3 application ideas

The Zero-Max CD(R) Coupling is a unique hybrid coupling, combining the best features found in both steel-disk and elastomeric couplings. Through its patented open-arm design and use of rugged composite materials, the coupling offers the high misalignment capacity found in many elastomeric couplings, but with higher torsional stiffness.

The primary function of these couplings is to transmit power from one section of a machine to another section. The floating shaft coupling described here connects together gearboxes that are located at distances on the order of 12 inches or more.

The standard floating shaft coupling can be modified easily to meet the requirements of many different kinds of applications. This article describes three applications in detail.

CD Coupling performance specs-The standard Zero-Max CD Coupling combines high misalignment capacity with high torsional stiffness.
Floating shaft Single flex Double flex
Diameter 2.25 to 6.75 inches 1.85 to 12 inches 1.85 to 12 inches
Continuous rated torque (inch-lbs) 270 to 10,300 47,200 47,200
Torsional stiffness (in-lbs/deg) 3,379 to 157,561 328,095 159,730
Maximum speed (rpm) n/a 3,000 2,100
Misalignment:
Parallel 0.053 inch per inch DBSE* 0.040 inch 0.137 inch
Axial 0.0600.220 inch 0.250 inch 0.500 inch
Angular 3 n/a n/a
* Distance Between Shaft Ends

High torque, small footprint

Design application: M1A2 Abrams Main Battle Tank

Coupling function: Floating shaft coupling for auxiliary drive for an enhanced air-filtration system for the M1A2 Battle Tank.

Design challenges: Increase speed and torque to intake scavenger fan in the same space/size envelope as the original coupling. Specifically, increase power from 5 to 18 hp, which imposed higher operating loads on the connecting coupling between the oil cooler fan on one end and the scavenger fan on the other. A larger, torsionally soft coupling could have been used to handle the increased torque requirements. However, a larger coupling would require major changes to the ductwork of the entire cooling system, including potentially expensive changes to both right angle gear box assemblies. The work envelope for the coupling assembly could not be altered.

Design solution: Engineers developed a customized version of the Zero-Max Model 22 CD coupling with a 21/4-inch overall diameter, a 7/8-inch bore, and a disk pack at each end of the coupling. They also thickened up each of three disks that make up each disk pack from 0.050 to 0.070 inches. The added disk thickness improved coupling stiffness and strength. To reduce stress at the bolt hole locations on the disk arms, engineers also redesigned the bushing/bolt interface to carry the increased torque. The disks themselves are left unfinished to facilitate required decontamination washdowns in case of nuclear exposure.

High power and oscillating loads

Design application: Wind turbine generator

Coupling function: Floating-shaft coupling for giant wind turbine drive train delivering 2,000 kW power. Operating life for the wind turbine is projected at 20 plus years.

Design challenges: Achieve high strength and accommodate up to 2 degrees misalignment in a high-power application with maximum coupling reliability and longevity. Absorb changing torque and misalignment transmitted to the drive train by the wind. Provide a maintenance-free coupling in a size 50% smaller and lighter than elastomeric designs and at a 25% lower cost.

Design solution: A customized, larger version of the Zero-Max CD Coupling using two 8-bolt disk packs in a spacer-coupling configuration. Overall disk diameter is 460 mm with a coupling length of 578.5 mm. The coupling mounts to diameters of 150 mm on each end. By increasing disk arm length, more flexibility was added to the coupling thereby absorbing the oscillating aerodynamic loads. Disk material is not affected by changing climate conditions and requires no maintenance.

Minimal torsional deflection, maximum torsional rigidity

Design application: Multiple station offset printing press

Coupling function: A floating-shaft coupling used to connect a series of print stations. The coupling must provide minimal torsional deflection and maximum torsional rigidity to maintain print registration. The press prints 2,000 fpm of a continuous stream of paper.

Design challenges: The coupling requirements for torsional stiffness were 5.5 times higher than the highest rated catalog coupling. The coupling also was required to withstand a corrosive environment created by the inks and other chemicals used in the printing process. Maintaining torsional rigidity while using an extended coupling spacer was an added challenge.

Design solution: Zero-Max developed a CD Coupling that would utilize a 12-bolt disk pack and a larger diameter spacer. In order to have a zero backlash connection between the coupling hub and gearbox shaft, use of a shrink disk was required. A special isotropic disk pack material was required to transmit the torque and maintain torsional rigidity. The fibers of the disk pack are orientated at 0, 30, 60, 90 degrees , etc. (Standard Zero-Max coupling disk pack fibers are orientated at 0 and 90 degrees ). The coupling also employs a special spacer, enhancing the coupling's torsional stiffness. To design this coupling for maximum performance, Zero-Max used finite element analysis.

For more information

Go to www.designnews.com/info or enter the number on the Reader Service Card:

Customized and standard versions of the Zero-Max CD Coupling: Enter 550 or e-mail author Brian Onkst at [email protected] zero-max.com

Product News

Product News

Spur gearheads

NEMA size 34 spur gearheads from this company are said to offer a lower cost alternative to more complex planetary designs. The products feature simple clamp-on pinions which are said to allow easy field installation, and provide torque multiplication, speed reduction, inertia matching, and resolution enhancement for dc servo, stepper, and brushless servo motors.

Stock Drive Products, Box 5416, New Hyde Park, NY 11042-5416; FAX (516) 326-8827; www.sdp-si.com.

For Information, enter 669

Stepper/servo brakes

FEB (Front End Brake) is said to be a failsafe, power-off brake designed to be mounted on the front end of stepper or servo motors as a safety feature or for holding loads in place by acting as a parking brake. The brakes are available in NEMA 23 and 34 sizes, offer torque ranges from 4 to 106 in-lbs., and are said to be compact, powerful, and cost-efficient.

Electroid Co., 45 Fadem Rd., Springfield, NJ 07081; FAX (973) 467-5656; www. electroid.com.

For Information, enter 670

Metric gears

An expanded line of metric gears and accessories is now available from this company. Products available include spur gears, internal gears, screw (crossed helical) gears, helical gears, racks, miter gears, bevel gears, worms and worm gears, and gear couplings. Materials available include case hardened steel, stainless steel, brass, aluminum, bronze, Nylon, and Duracon.

Quality Transmission Components, 2101 Jericho Tpk., Box 5416, New Hyde Park, NY 11042; FAX (800) 737-7436; www.qtcgears.com.

For Information, enter 671

Belt-driven slides

A series of five belt-driven slides from this company are said to offer speeds of up to 5 m/sec in a wide variety of motor and carriage configurations. The slides, designated as Blue Line 1, Blue Line 3, and ZF 1, 2, and 3, all feature an HTD timing belt and home position switches with a reported accuracy of under 0.1 mm and repeatability of less than 0.2 mm.

Techno-Isel, 2101 Jericho Tpk., New Hyde Park, NY 11042-5416; FAX (516) 358-2576; www.techno-isel.com.

For Information, enter 672

Ac drive control

MAC Series drive controllers are designed to work with most 1-hp or smaller, 115 or 230V ac three-phase induction motors. The product is reportedly capable of a 100:1 speed range, and is also said to operate with constant torque from 0 to 60 Hz and constant horsepower above 60 Hz. The product also incorporates features which are said to increase torque boost during acceleration.

Minarik, 905 E Thompson Ave, Glendale, CA 91201; FAX 818-637-7549; www.minarikcorp.com.

For Information, enter 673

Gear reducers

Bravo? cast aluminum-housed worm gear reducers from this company have been expanded to include double reduction ratings in either worm/worm or helical/worm combinations. Both options are said to offer high torque and low speeds in a compact and lightweight package, and can be ordered as Gear+Motor? packages. The product also features impregnated and machined bearing caps with Nitrile seals.

Leeson Electric Corp., Box 241, Grafton, WI 53024-0241; FAX (262) 377-9025; www.leeson.com.

For Information, enter 674

Helical drive

Ultramite? Type UJ Screw Conveyor Drives are designed for beltless shaft-mounting applications. The products feature CEMA screw conveyor designs, and are said to provide ratios from 5:1 to 20,000:1, and deliver 0.19 kW to 0.30 kW. The product is available in base-, shaft-, or flange-mounted styles, in five different sizes, and in horizontal or vertical mounting.

Falk, Box 492, Milwaukee, WI 53201-0492; FAX (262) 377-9025; www. falkcorp.com.

For Information, enter 675

Dc drives

SIMOREG 6RA70 "DC Master" adjustable-speed drives are said to feature expanded performance characteristics and functionality. The products are available in output ranges from 7.5 to 1000 hp at 500V dc, and extended high-horsepower designs up to 8000 hp. The company says that users need to learn only one system of programming and configuration to operate the full product line.

Siemens Energy & Automation, 3333 Old Milton Pkwy., Alpharetta, GA 30005; www.siemensvpc.com.

For Information, enter 676

Brushless motor

ELCOM ST? Size 23 slotted brushless dc servo motors are now available in a standard 2 inch stack length to satisfy specific torque requirements. The motors feature high energy bonded neodymium magnets, and offer continuous output torque up to 49 oz/inch at motor speeds of up to 8,000 rpm and power output of up to 188W. Applications include medical diagnostic devices, computer peripherals, and office automation equipment.

Pittman, 343 Godshall Dr., Harleysville, PA 19438-0003; FAX (215) 256-1338; www.pittmannet.com.

For Information, enter 677

CAM control

ECM010 CAM controllers are designed for use with steppers and digital input servo motors to increase the flexibility of motion control systems. The product is said to be quickly and easy configurable for just-in-time manufacturing and testing operations. It can reportedly be connected to 15 other controllers to coordinate complex multi-axis operations.

Nyden Corp., 2610-B North First St., San Jose, CA 95134-2014; FAX (408) 232-7701; www.nyden.com.

For Information, enter 678

Brush motors

This company offers a line of off-the-shelf and custom brush-type motors, gear boxes, and gearmotors for use in appliances, check readers, vending machines, and juke boxes. Torque is said to range from 0.5 to 18 oz-inch of running torque, and 2 to 110 oz-inch of stall torque, in sizes ranging from 16 to 52 mm in diameter, and 19 to 96 mm in length.

Source Engineering, 3400 De La Cruz Blvd, Santa Clara, CA 95054

For Information, enter 679

Linear motors

5020 brushless linear motors are designed for use in the packaging, material handling, robotics, and machine tool industries. The product uses 3-phase brushless dc technology similar to rotary brushless motors, but with ring-shaped rare earth magnets arranged in alternating polarity down the length of the shaft.

California Linear Devices, 2236 Rutherford Rd #119, Carlsbad, CA 92008; FAX (760) 603-0049; www.calinear.com.

For Information, enter 680

Product News

Product News

Fiber array

FT8R AND FR8R fiber-to-fiber RAID systems from this company are designed to provide a server-independent, end-to-end fiber RAID solution for enterprise and midrange server markets. Capable of supporting up to 5.2 terabytes, the system incorporates fiber channel drives and hosts, and is scalable to accommodate growing storage needs by adding up to 124 drives.

Trimm Technologies, 350 Pilot Rd., Las Vegas, NV 89119; FAX (702) 361-6067; www.trimm.com.

For Information, enter 688

Static mixers

Kenics(R) KM Series Static mixers feature a patented helical mixing element which is said to provide complete radial mixing and flow division for any combination of liquids, gases, and solids. Smooth element geometry is also said to result in efficient mixing of miscible fluids in laminar or turbulent flow, and reportedly disperses immiscible fluids or gases while producing low pressure drop.

Chemineer, 125 Flagship Dr., North Andover, MA 01845; FAX (978) 687-8500; www.chemineer.com.

For Information, enter 689

Crank handle

Available in standard and metric sizes, this company's line of crank handles features aluminum bodies and retractable black phenolic plastic handles. Designed for applications where the handpiece does not protrude when not in use, the handle locks in the operating position, and is also available with custom bores, keyways, and set screw holes.

J.W. Winco Inc., Box 510035, New Berlin, WI 53151; FAX (800) 472-0670; www.jwwinco.com.

For Information, enter 690

Machining centers

CV-600 and CV-1000 Vertical CNC machining centers have just been introduced by this company for use in small- to medium-sized shops. Both products feature cast iron construction, 15-hp spindle drives with optional speeds of up to 12,000 rpm, the Fanuc control and Fanuc servo drives on X, Y, and Z axes, and reportedly highly accurate linear way systems.

ColchesterCNC, 5801 Creek Rd, Cincinnati, OH 45242

For Information, enter 691

Crimper

The P51 crimper is said to provide 280 tons of swaging force within a compact machine, and reportedly accepts hoses up to 21/2 inches diameter and performs 720 crimps per hour. Die movement is said to be constant centerline for precise part orientation, and the product is available with options such as mechanical back gauges and foot pedal operation.

Finn-Power USA, 710 Remington Rd., Schaumburg, IL 60173; FAX (847) 885-9692.

For Information, enter 692

Turning center

Hawk TC-300 CNC Turning Centers are said to provide increased power and capacity for a variety of turning applications. The product is equipped with a hydraulically activated 12-inch chuck, powered by a high-torque spindle motor capable of producing a reported 3,000 MTDR at 3,000 rpm. Also featured is a toothed-belt drive which is said to eliminate side loading.

Cincinnati Machine, 4701 Marburg Ave., Cincinnati, OH 45209-1025; FAX (513) 841-8991; www.cinmach.com.

For Information, enter 693

Quick change mounting

Hydraulic Ball Lock? quick-change fixture mounting systems are said to combine this company's Ball Lock mounting technology with hydraulic power to provide high speed and a positive mechanical lock. Shanks are hydraulically unlocked, but lock mechanically and reportedly won't release unless hydraulic pressure is reapplied.

Jergens, 15700 S Waterloo Rd., Cleveland, OH 44110; FAX (216) 481-6193; www.jergensinc.com.

For Information, enter 694

Product News

Product News

Pneumatic actuators

CRHD linear actuators for hygienic environments utilize the same stainless-steel design that allows the device to function in aggressive environments where acids, bases, and powerful cleansers are used. To function in sterile environments, the actuators incorporate a cylindrical shape and integral mounting component on the rear cap. Since there are no corners or debris collection points on the exterior surface, fluids and matter drain off during cleaning.

Festo, Box 18023, 395 Moreland Rd., Hauppauge, NY 11788; FAX (800) 963-3786; www.festo-usa.com

For Information, enter 704

Valves

The A45 valves, available with orifices of 2, 4, and 6 mm, are used on machines and systems to control liquids and gases. The valve line is ideal for applications where 100% tight shutoff is required, such as pressure decay testing machines. They offer all-stainless-steel construction, with working pressures to 1,950 psi. springer co-ax inc., Box 7204, Penndel, PA 19047; FAX (888) 757-4060; www. coaxvalves.com.

For Information, enter 705

Pumps

SV600 Series of solenoid-operated dispensing pumps employs an O-ring pumping system, which seals the piston while allowing the pump chamber to refill. The piston is retracted when the solenoid is energized, allowing liquid to enter the volume above the pump O-ring. A return spring pushes the piston back down when the coil is de-energized. The user can adjust volume output per stroke, and can control flow rate per minute.

Valcor Engineering Corp., 2 Lawrence Rd.,Springfield, NJ 07081; FAX (973) 467-8382; www.valcor.com.

For Information, enter 706

Air cylinders

Series BT and BTM stainless-steel body, light-duty air cylinders are offered with 250 psi nominal air pressure, eight standard bore sizes from 7/16 inch through 2 inches, and 21 mounting styles. Series BTM stainless-steel air cylinders offer piston sensing capability with adjustable reed-switch or solid-state switch configuration. A Nitrile-Barium piston magnet surrounds the entire diameter for dependable switch activation.

Miller Fluid Power, 800 N. York Rd., Bensenville, IL 60106; FAX (708) 766-3012.

For Information, enter 707

Valves

Check relief valves are designed and manufactured to customer requirements. The valves are constructed with a one-piece housing and operate at 3,000 and 6,000 psi. With various cracking pressures, metal-to-metal or soft seats provide leak- free performance with low pressure drop. Sizes range from 1/4 inch to 2 inches in steel, stainless steel, and brass.

Fluid Line Products Inc., 38273 Western Pkwy., Box 1000, Willoughby, OH 44096; FAX (440) 946-9472; www. fluidline.com

For Information, enter 709

Sanitary pump

Made of food-grade 316 stainless steel to meet 3A sanitary standards, a pump line incorporates elastomers that satisfy FDA requirements. The devices are capable of handling a wide range of applications from clean, clear liquids to viscous and abrasive fluids.

Moyno Inc., Box 960, Springfield, OH 45501; FAX (973) 327-3177; www.moyno.com

For Information, enter 710

Actuators

Integrated actuators, for medical applications such as automated injection systems or circulation assist pumps, offer smooth and quiet motion. Complete sealing keeps lubricants and contaminants out. The linear actuator series integrates a planetary roller screw into a brushless servo motor and is capable of speeds to 40 inches/sec and peak forces to 16,000 lbs.

Exlar Corp., 1470 Lake Dr. W., Chanhassen, MN 55317; FAX (952) 368-4359; www.exlar.com.

For Information, enter 711

Diaphragm valves

A patented radial-diaphragm-valve design eliminates entrapment areas and allows for easy drainage. It can be manufactured in a wide range of configurations to include multiple valves and multiple ports. This versatility can result in a more compact flow stream, built with fewer valves, less piping, and fewer connections. Designed and tested for durability and long cycle life, particularly in steaming applications, every diaphragm is machined from virgin PTFE.

Swagelok, 31400 Aurora Rd., Solon, OH 44139-2764; FAX 440 349 5806; www.swagelok.com.

For Information, enter 712

Pressure sensors

Miniature amplified pressure sensor utilizes a monolithic design based on piezoresistive technology. The components that provide temperature compensation and output amplification are located on the silicon piezoresistive chip. It is constructed of glass, solder, and silicon with a stainless-steel port. The 6-pin DIP package is designed for printed circuit board mounting.

Honeywell, 11 W. Spring St., Freeport, IL 61032; FAX (815) 235-6545.

For Information, enter 713

Product News

Product News

FEA

ANSYS(R) 5.7 is designed to offer the most real-life solutions for nonlinear analysis. Instead of using simplified, constant parameters, users can allow variations in material properties, component geometric extensions, external loads, and boundary conditions. It handles the extra computing load with a scalable shared memory parallel solver, and a distributed memory solver.

ANSYS Inc., Southpointe 275 Technology Dr., Canonsburg, PA 15317; FAX (724) 514-9494; www.ansys.com.

For Information, circle 681

CAD

thinkdesign 6.0 is designed to bring high-performance CAD to the desktop, featuring a new speech-enabled GUI that reduces the number of dialog boxes and command-line functions. It also allows late-stage parametric model changes, reusing design elements, and associative curves and surfaces. It even offers a web-based 3D adventure game, designed to make training fun.

think3, 2880 Lakeside Dr., Suite 250, Santa Clara, CA 95054; FAX (408) 727-0237; www.thinkthree.com.

For Information, circle 682

Software development collaboration

Software Central is software-development collaboration software designed to enable real-time communication, and parallel, iterative design processes. It integrates with a company's existing tools to lower administrative burdens. Users must run the eMatrix9 Application Exchange Framework to use it.

Matrixone, Two Executive Drive, Chelmsford, MA 01824; www.matrixone.com.

For Information, enter 683

CFD

COSMOS/Flow is a computational fluid dynamics program embedded in COSMOS/Works, the SolidWorks analysis module. Developed with the non-specialist in mined, it determines how fluids will flow through and around a model, for applications with automobiles, airplane wings, or exhaust valves. It can also simulate gases, heat transfer, and other forces.

SRAC-Structural Research & Analysis Corp., 12121 Wilshire Blvd. 7th Floor, Los Angeles, CA 90025; FAX (310) 207-7805; www. cosmosm.com.

For Information, circle 684

CAM

ESPRIT CT is what happens when ESPRIT 2000 integrates Charmilles Technologies' CT Expert system. ESPRIT CT allows users to do streamlined, automated programming of Wire EDM machines. It offers 3D data exchange capability, has a database of machine settings, and automates machine file output.

DP Technology, 1150 Avenida Acaso, Camarillo, CA 93012; FAX (805) 388-3085; www.dptechnology.com.

For Information, circle 685

Analysis software

BoltFAST(TM) is bolted joint analysis software that allows engineers to determine the fatigue endurance limit of a thread, the amount of embedding anticipated in the joint, and the optimal tightening torque for given friction conditions. It can calculate whether a bolted joint can sustain certain forces, the amount of force necessary to strip threads, and the best tightening torque and clamp force.

Sensor Products Inc., 188 Route 10 Suite 307, East Hanover, NJ 07936-2108; FAX (973) 884-1699; www.sensorprod.com.

For Information, circle 686

Composite design software

Version 3.3 of FiberSIM/UG allows Unigraphics CAD users to design composite components, with new features including the ability to import stored ply definitions, including material name, fiber spacing factor, simulation type, and geometric data such as holes and markers.

Composite Design Technologies, 486 Totten Pond Rd., Waltham, MA 02451; FAX (781) 290-0507; www.cdt.com.

For Information, enter 687

Float like a butterfly, sting like a...robot

Float like a butterfly, sting like a...robot

Never underestimate the appeal of metallic carnage. That's the idea behind BattleBots, the weekly television series that pits dueling robots against one another. With their builders pulling the strings via radio controls, these robotic fighters go mano a mano for three minutes and attempt to batter each other into submission. If only one robot works at the end, it wins. If both BattleBots are still standing-or more likely, rolling-judges award a decision to whichever robot inflicts the most damage.

Not surprisingly, BattleBots take a beating during these mechanical slugfests. The robots all sport weapons-anything from a simple hammer or spike to circular saws. The current heavyweight titleholder, Carlo Bertocchini, recalls the time his robot, BioHazard, had an eight-inch gash torn through its 3/16-inch titanium armor by another robot's saw-like spinning disc. "That disc moves about 300 mph on its edges. When it hit my robot, sparks flew everywhere," Bertocchini says, noting that the attack launched the 208-lb BioHazard several feet into the air. BattleBots also have to withstand collisions with arena walls and other robots. In the heavyweight division, robots weighing more than 200 lbs commonly collide head on at 15 mph. One former heavyweight champ, Gage Cauchois, reports that he even tests his robot's ability to "take a punch" with some full-speed dumpster tilting. And, as if the other robots weren't bad enough, BattleBots also compete amidst hazards in the ring: circular saws, spikes, and hammers.

By the time a BattleBot gets ready to rumble, its builder has typically spent months on design and makeshift manufacturing, cobbling the robot together from a combination of custom-fabricated and off-the-shelf components. And the builders, who may or may not be engineers, have to juggle many of same design constraints found in many a commercial engineering project. BattleBot rules, for example, impose strict weight limits. The builders also struggle with packaging limitations and powertrain design. Weapons and fighting style drive many of engineering decisions, according to Bertocchini. "A ramming robot might need more speed than a robot with an impact weapon," he says. "And that has design implications from the size of the motors to the overall construction of the BattleBot." BattleBot builders even have their own take on life-cycle engineering, with an acceptable lifespan for many components defined as a three-minute BattleBot bout. Finally, because most builders still compete as hobbyists, they work hard to avoid needless cost and complexity.

"The great thing about BattleBots is that there are many ways of solving the same engineering problems," says Jason Dante Bardis, a BattleBot competitor who's working on his doctorate in mechanical engineering. Here's a look at the very different engineering approaches taken by three contenders in the heavyweight division.

BioHazard

Behind the robot: Built by Carlo Bertocchini, a mechanical designer for Raychem Corp., BioHazard won last year's heavyweight competition.

Specs: Weighing in at 208 lbs and measuring 36 x 48 x 6.25 inches, this robot epitomizes the "low-slung box" approach.

Weapon: A scooping arm unfolds from a shallow recess in the top of the robot and lets Biohazard lift competitors, either to flip or shove them into ring hazards and walls.

Locomotion: BioHazard's entire drivetrain squeezes into a pair of 3 x 3-inch-square aluminum extrusions. Each extrusion, one for each side of the robot, houses a two-stage, 6:1 chain reduction and three 4-inch-diameter wheels. Bertocchini decided to use extrusions mostly for the sake of rigidity. "Using a single structural member for the drivetrain prevents any flexing that could misalign the sprockets," he points out. Two 3.5-hp electric motors and a 24-V battery power Biohazard. "I rewound the motors and re-machined the commutators for a better performance profile," Bertocchini says, explaining that his battle strategy needs to slightly favor forward motion.

Engineering challenges: "The weapon was the trickiest thing to engineer," says Bertocchini. Made from a four-bar linkage, the scooping arm has to unfold from its nearly flat space to an extended length of 18 inches. "It takes a tremendous amount of force to move the fully-loaded arm," he says, citing an average of 1,400-lb average mechanical advantage through its range of motion. Bertocchini drives the arms with two 3.5-inch linear actuators. Though rated to only 400 lbs, the actuators underwent extensive modifications-including a new set of needle bearings and beefed up stanchions-to triple its load capabilities. The actuator works in conjunction with what Bertocchini describes as a "complicated bell crank-torsion shaft mechanism." Squeezed between arm and actuators, this mechanism bears the brunt of the load and had to be machined from a specialty steel alloy developed for aerospace applications. (Aeromet from Carpenter Technologies). Bertocchini prototyped the crank mechanism in pre-hardened P-20 but found that this conventional steel wouldn't hack it. "It didn't fail, but it did flex," he recalls.

Finding the right materials for BioHazard also took some doing. With a 3 x 4-ft area to cover, Bertocchini needed a material with a good strength-to-weight ratio. He picked 3/16-inch-thick titanium. "I needed a high-tech material to stay within the weight limitation," he says, noting that he got away with magnesium on earlier, sparsely armored versions of BioHazard. Underneath the robot, he installed alumina ceramic tiles to protect the undercarriage from the BattleBot's circular saws. "Hardened steel would have weighed at least 5 times as much," he guesses.

Sponsors: PTC contributed Pro/Engineer software (Enter 545). W.M. Berg chipped in with precision mechanical components, like the sprockets (Enter 546).

Towering Inferno

Behind the robot: Newly built for this month's heavyweight competition, Towering Inferno has yet to see any action. But its builder, Jason Dante Bardis, a doctoral candidate in mechanical engineering at Univ. of California Santa Barbara, has built an small army of fighting robots over the past 10 years.

Specs: Measuring 28 inches high, 40 inches long and more than 40 inches wide, Towering Inferno lives up to its name-the first part of it anyway. But stature doesn't set the robot apart as much as a design that even Bardis describes as "weird." In contrast to the more common robot-as-box approach, Towering Inferno consists of two wheel modules joined by a 42-inch chrome-alloy shaft. Bardis builds the wheel modules by attaching arc sections to the exterior of prism-shaped aluminum and polycarbonate "pods." Bardis briefly considered cylindrical wheel modules, but instead chose the structural strength and visual impact of a triangular cross section. To keep wiring to a minimum, each hollow pod houses a complete powertrain and can move independently on the shaft-and a set of self-aligning bearings-for tank-style steering.

Towering Inferno tips the scales right at the 210-lb weight limit. Bardis says he felt comfortable playing so close to the limit in part because he designed the robot in Pro/E and used the CAD software to keep a running tally of weight as he went through the design and building process. "Pro/E got me within one-tenth of a pound," he says.

Weapon: Bardis hopes to pound his way to victory with a pair of sharpened Home Depot hammers mounted on 30-inch arms that rotate about the same shaft as the wheel modules and normally trail behind the wheels. During an attack, the hammer swings over the top of the robot. Unlike some earlier designs, which depended on robot momentum to swing the hammer down, Towering Inferno can swing its hammers from a dead stop. In fact, when Bardis is feeling really mean, he can even flail the hammers by modulating the motors.

Locomotion: In an innovative design twist, the hammers also do double duty as a drivetrain component. "The weapons are the means of locomotion," Bardis says. Rather than driving the wheels directly, Bardis instead uses Towering Inferno's 6:1 chain reduction to drive the hammers into the floor. As the hammers push downward, Bardis explains, they set up a counter-moment that rotates the wheels and propels the robot. Bardis himself describes his hammer drive as "a bit weird," but there's method behind his weirdness: Integrating the weapons and drive systems keeps component count and weight in check.

Towering Inferno runs on a pair of 24-V, 1.33-hp motors and a 24-V Hawker lead-acid batteries. Bardis says he likes these batteries because they combine two important aspects for a BattleBot power source: "They pump out a lot of amps and charge quickly." The first attribute allows the motors to operate at or near stall-a common condition as robots try to push each other around the ring. The second attribute lets Towering Inferno top off its batteries in the scant 20 minutes that separate BattleBot rounds.

Engineering challenges: Coming up with Towering Inferno's hammer-drive mechanism took up most of Bardis' initial engineering time. To make sure the concept would work, he first prototyped the robot in large Lego blocks. Once he knew the basics would work, he set out to design the biggest chain reduction that would fit between each pod's motor and drive shafts. ."I wanted a big reduction to get good torque," he says. "Because a lot of these contests turn into shoving matches."

Sponsors: Bell Everman handled all the CNC machining, including some relatively complex brackets that hold the prism pods together (Enter 547). Specialty Tool chipped in fasteners and tools (Enter 548). And PTC contributed a Pro/ENGINEER license (Enter 545).

Vlad the Impaler

Bio: The heavyweight champ in 1998, Vlad the Impaler is the creation of Gage Cauchois, a lighting designer turned robot master. In this year's heavy weight competition, Cauchois will compete with an revamped version of the same robot. "It's called Vlad 2001," he says.

Specs: At 208 lbs, Vlad consists of a steel frame clad with T6 aluminum and 3/16-inch polycarbonate sheet. The robots box-like housing, which is put together with bolts and screws, rides around on 12-inch polyurethane wheels. Except for stronger 7075 aluminum armor, Vlad 2001 uses similar materials and basic construction. The new design, however, has no dedicated top or bottom. Symmetrical about its horizontal axis, the robot runs equally as well if it's flipped completely over, according to Cauchois.

Weapon: Vlad gets its punch and its name from a front-mounted pneumatic lever arm whose sharpened prong threatens to pierce or flip any robot that gets in the way. A pair of CO2 cylinders and a cable-and-pulley mechanism allow the lever to lift up to 400 lbs, Cauchois reports. On Vlad 2001, the prong still works as a lever arm, but it's double acting so it can work regardless of which side of the robot is up. Attached at the robot's centerline, the new prong weapon dips downward to form a wedge when the lifting arm isn't in use. With a potential to flip over other BattleBots, the wedge gives Vlad a second means of attack.

Locomotion: A pair of 300-A, 3-hp PMDC motors and three Hawker dry-cell batteries drive Vlad-with the help of a 6:1 chain reduction. The revamped Vlad will be more powerful with custom-built 7-hp motors from a vendor that Cauchois won't reveal.

Engineering challenges: Win or lose, Vlad often takes a beating as two robots try to disable each other in an enclosed ring. "During a competition, the robots experience huge amounts of vibration, and they have to endure repeated impacts," says Cauchois. Much of the vibration originates in Vlad's chain drive. In a common BattleBot strategy, Cauchois deliberately picks undersized drive components in order to squeeze them into the robot's body and to make weight. Cauchois then runs those components well above their recommended speeds to give Vlad enough power and speed to win. Vlad's 3/4-inch, eight-tooth sprocket, for example, runs at speeds up to 4,000 rpm rather than a suggested maximum of 1,800 rpm.

"The resulting vibration goes right through the whole machine," he says. To sidestep the loosening caused by all the vibration as well as impact from other robots, Cauchois applies threadlockers like Rocky Balboa's cut man slathers on Vaseline. Medium-strength threadlockers secure all the bolts that hold the motor to the frame and also all the screws that hold the drive-train components in place. Retaining compounds keep the drive sprocket on its shaft. And Cauchois uses a wicking grade threadlocker on the screws that join armor plates. "Just about every place I could use a threadlocker or a retaining compound, I did," he says. "And nothing inside Vlad has ever come loose."

Cauchois has also found a way to dissipate the heat that plagues BattleBot motors. Some excess heat results from prolonged periods of operating motors at their stall torque. Even more comes from the common BattleBot strategy of "overvolting" motors-running 12-V motors at 24V to gain power at the expense of longevity. To cool Vlad's overburdened motors, Cauchois installs cooling fans he built from thrusters designed for radio-controlled airplanes. Describing the throughput of the cooling fans, Cauchois says these thrusters "are powerful enough to fly a two-pound airplane vertically."

Sponsors: Loctite Corp., which certainly shares Cauchois' fondness for threadlockers, sponsors Vlad (Enter 549).

Stepper motor avoids missteps

Stepper motor avoids missteps

Boone, NC -Given the small and delicate nature of the components it manufactures, International Resistive Company (IRC), a subsidiary of TT Group PLC, had to think carefully about the design of its testing and handling equipment. In particular, engineers required that the motor shaft maintain position and come to a dead stop in order to meet positioning tolerances.

As an example, one test process calls for the positioning of a rotary wheel that handles round resistors. "These resistors go through short-time electrical overload two times and are exposed to six times the amount of current for which they're rated. Each part gets tested both before and after. We count on the motors to help the equipment hold tolerances within a few thousands of a inch," says Roy Keller, electronic design technician.

IRC engineers didn't even consider servo motors for this application, because of the "jitter" that servo motors sometimes exhibit when trying to hold position. Although this movement is very small, Keller says that when bending small resistors, or testing their contacts, any movement at all can interfere with and invalidate the test results. Gain tuning or the addition of mechanical brakes to manage the problem were not options for IRC engineers.

Ordinary stepper motors, on the other hand, do not have jitter. But they can miss a step when the rotor lags behind or moves ahead of the excited winding, potentially causing an unscheduled shutdown of the production line or worse.

Seemingly having their cake and eating it too, engineers replaced the existing open-loop step motors with AlphaStep motors from Oriental Motors (Torrance, CA). The motor contains a built-in resolver that continuously monitors motor shaft position. Under normal conditions, the driver operates in open-loop mode similar to an ordinary stepper motor. But when the rotor position gets out of sync with the excited winding by more than 1.8 degrees, the motor switches to closed-loop control to maintain synchronicity.

Another alternative would be to put an encoder on a conventional step motor-but cost was an issue for IRC. "An encoder for a regular step motor costs between $400 and $500. In contrast, the price tag on the small ASC66 AlphaStep is less than $650 including the resolver, and the ASC98 is under $900," Keller says. "Servo motors for these applications can cost two or three times as much."

In addition to testing equipment, IRC uses the stepper motors in materials handling applications. For example, one AlphaStep drives a conveying system with parallel rails, in which the inner rail moves up, lifts, and drops parts over the outer rail.

The motor drives the cam in one direction, rotates 60o, and then returns to the start position. It raises and lowers the teeth of the conveyor, the motions of which have to be very precise given that the resistors are on the order of just a few mils thick. In another application-a machine that bends and tests the resistor-a motor drives a gearbox that converts the motor's circular motion into vertical and horizontal motion.

"It does 1,000 steps per revolution with all the forming and testing keyed via the step count," says Keller.

In each operation, the motor stops precisely. Keller says, "The resolver counts the steps and will try to make up any missed ones. If the motor can't complete its steps, it will stop and send an alarm, instead of continuing to miss steps and possibly damage the equipment."

Another manufacturing application at IRC consists of filling resistors-some as small as 0.250-inch long, with concrete that functions as an insulator. In this case, Keller uses a geared AlphaStep motor. "The geared version allows us to increase the number of steps, and at its coarsest setting gives 2,500 steps [as compared to 1,000 for the non-geared version] for extreme precision. That's important, because the resistor shell must be filled to a specific level. The geared motor also gives us 78 inch-lbs of torque for this application to achieve rapid fill times," he says.

"The primary advantage of the AlphaStep is that we get feedback only when we need it, at an economical price," says Keller."

For more information

Go to www.designnews.com/info or enter the number on the Reader Service Card:

AlphaStep motors from Oriental Motor: Enter 552

How the motor technologies stack up
Motor type Type of control Dead stop capability? Cost
Conventional stepper Open loop Yes 1.0
Servo Closed loop Achieved through tuning, filters,or mechanical brake 1.5
AlphaStep motor with built-in resolver Open loop during normal operation; closed loop to maintain synchronicity Yes 1.1
Table source: Oriental Motor

Standards help realize open fieldbus protocols' flexibility and lower cost

Standards help realize open fieldbus protocols' flexibility and lower cost

Charles W. Cook, P.E., is currently WAGO USA's Product Manager of Advanced Electronic Products, including WAGO's I/O System. He is an Electrical and Computer Engineering graduate of the University of Wisconsin-Madison. Previously Cook served as WAGO's Engineering Supervisor. Prior to his tenure at WAGO, Cook worked in product development for electronic components companies such as Square D.

Faster, better, cheaper have been bywords at NASA. But in industry as well, industrial-controls engineers are turning to open fieldbus protocols for more economical ways to easily integrate new technologies into current systems for greater efficiency. Common standards will reduce their learning curve and support costs.

Design News: How are the needs of your customers changing?

Cook: Our customers are looking for more reliability and greater efficiency. They are also looking for ways to integrate new technologies with existing ones without having expensive upgrades and steep learning curves.

Q: How do you plan to accommodate such changing needs?

A: The first step to address the need for greater flexibility and lower costs across industrial communication was the development of open fieldbus protocols. WAGO is fulfilling these demands with our fieldbus independent I/O system. No matter what the protocol, the system coordinates different machine centers and cross over, whether it includes DeviceNet, Profibus, Ethernet, Interbus, or Modbus. Such a modular I/O system increases flexibility of control engineers to change protocols and even update their technology to implement Ethernet capabilities or distributed control.

Q: What technologies will come into play to meet these changes?

A: Ethernet and distributed control technologies have been inhibited in industrial controls due to a lack of commonality between various companies' offerings. For distributed control, we offer IEC 61131-compatible software tools. For Ethernet, we are active and pushing for one or two common standards. This will serve customers by reducing their learning curve and our support costs.

Q: In five years, what will be the hot I/O and connectivity technology?

A: As customers have sought to reduce wiring by using industrial data networks, expect this trend to move even further into wireless data communications.

Q: With mechanical engineers getting more involved with specifying electronic and control systems in their designs, how can manufacturers of such systems educate them to be more effective?

A: Keeping things simple and logical will allow any engineer to use one's products.

Q: How is the Internet affecting your business and the way your customers do business?

A: Support and more support is what our customers want from the Internet. Customers want everything from manuals to downloadable tools to access to our manufacturing data that can quickly alert them to any changes. In its infancy, the Internet was used primarily by industry as both a sales and marketing device promoting new products and as a research tool for investigating new possibilities. In recent years, connector manufacturers have begun to utilize the interactive benefits of the Web in much more functional ways. Products can be specified online, designed, assembled, and customized. Through e-commerce activities, stock can be checked, deliveries verified, and orders placed, freeing up professional staff to do what they do best-build relationships and add value. Aside from these online pre-sales activities, post-sales documentation, customer support, and Web-based training sites are also now becoming readily available online.