IF IMITATION is the sincerest form of flattery, Reading Body Works has just paid the automobile manufacturers the supreme compliment.

Reading's new Aerotech service body is influenced by the way Detroit designs vehicles-and the way it manufactures them. For the truck body industry, it is a different type of product that requires much more than a shear and press brake to fabricate.

The Aerotech borrows heavily from automotive designers and suppliers. Most of the Aerotech body panels include either a simple radius or compound curves, much like the surfaces of today's truck cabs. Some of the component pieces, such as the fuel fill door, are the same as those installed on cars and pickups. Others, such as the compartment doors, use similar construction and have door hinges and spring detent retaining mechanisms comparable to those used on automobiles. And for styling, Reading went to the same design company that Chrysler used when developing the Dodge Viper and Plymouth Prowler.

Like these two Chrysler vehicles, the curved lines of the new Aerotech service body require some sophisticated and costly machine tools to fabricate. The most significant: a 750 ton Pacific draw- forming press and a five-axis, robotic laser system for trimming and cutting the curved parts.

The Aerotech project is the result of a four-year program. Reading started with lengthy research of its distributors and end-users to develop a wish list of service body features.

"We asked what the perfect service body would be like," says Dan Perlman, manager of manufacturing. "We developed a wish list. One of the most common items on the customer list was a service body that complements the truck cab."

The research, which included focus groups and questionnaires, indicated that customers in general were looking for the following qualities: security, the ability of the compartments to keep out water, corrosion protection, concealed locks, and aerodynamic styling.

With these attributes in mind, Reading turned to an independent engineering company in Detroit to create the basic concept. Reading engineers, then fine-tuned the design to reflect specific industry wants and needs.

"We wanted a brand new product," Perlman says. "If someone at Reading designed it, they would design a Reading body. That's why we looked to an outside company for design help- so that we would be able to start fresh."

The result is the application of automotive industry technology to a service body. For example:

• Automotive lighting. The Aerotech body comes from the manufacturer with a full complement of lights (including back-up lamps) already installed. An automotive wiring harness is ready to connect to the chassis.
• Reshaped doors. Wraparound design of the compartment doors reaches the tops of the side packs. This results in a much narrower door header, allowing the user greater access to the extreme top of the compartments.
• Concealed door hinges. The patent-pending design provides a flush surface and enhanced security. Spring-loaded door hold backs use detents to hold vertical doors in place at 90-degree angles.
• Removable automotive-style door gaskets. The flange-mounted rubber gaskets cover the perimeter of the door opening.
• Removable tailgates. Patterned after those of a pickup truck, the tailgate can be removed by tilting it 30-degrees and lifting it up. Locking hardware and double-panel construction are similar to that found on pickup tailgates.
• Automotive-style fuel fill doors. The doors are produced by a manufacturer that supplies similar products to automobile manufacturers. Aerotech bodies come standard with two factory-installed doors on the street side of the body.
• Automotive paint application system. For almost 10 years, Reading has painted its bodies by immersing them in electrically charged tanks. The system, patterned after those developed by automobile manufacturers, will be used on the Aerotech body.

Relieving Stress

The curved design of the Aerotech body departs from the straight sides and 90-degree angles of traditional service bodies. The new look helps the body conform to the style of the cab. However, the curved lines may have a more practical benefit-a design that may be more resistant to stress.

"Our basic service body design has been around 40 years and has held up well," Perlman says. "But we believe the Aerotech will be even more durable."

Perlman bases his prediction on finite element analysis that Reading has performed. When standard designs are subjected to racking, the stress tends to concentrate at the corners of door openings. The rounded corners of the new design spread the stress over a wider area, decreasing the likelihood of fatigue cracking.

"Our analysis shows very little concentration of stress," Perlman says, displaying the results of finite element analysis performed for both the Aerotech and standard Reading designs. The drawings locate stress risers, particularly around the door corners of the standard design. Virtually no significant stress concentration was indicated on the Aerotech.

The new design has advantages over the standard service body, but it required substantial expenditures for plant equipment. The two most costly machine tools: a 750-ton Pacific draw- forming press, and a five-axis robotically operated laser from Prima U S.

The draw-forming press produces the compound curves of the Aerotech body. Among parts Reading draw forms are fender panels, end panels, and doors.

To draw form a part, the 750-ton press first clamps the steel sheet securely. A male die then comes down from above to stretch the steel into place. As the steel is being stretched, the computer controller of the press regulates the holding pressure of the outer ring that holds the steel. This allows the steel to slip just enough so that it does not rip.

"Stretch forming has been used for years by automobile manufacturers," Perlman says. "Stretching gives the sheet metal a memory. This allows it to spring back when dented slightly and to hold its shape through years of use."

Moving a Mountain

The draw-forming press stands more than 20 feet high and weighs more than 250,000 pounds. Six truck trailers were needed to transport the press to the Reading plant in July.

Reading installed the press in a pit near the Prima laser. A smaller pit will house a coil line capable of processing 50"-wide material. The company' s largest line today can handle up to 30"-wide coils.

Everything about the press is massive. The plant routinely must shuffle extremely heavy dies back and forth between the press and the storage racks. To accommodate the dies (the largest weighs 25,000 lb), Reading purchased a special vehicle similar to a forklift. The company's hydraulic die- moving truck has a 40,000-lb capacity.

The price tag of the press matched its size. The machine itself cost more than $500,000. However, the complement of 20 different die sets represents an investment of more than $1.5 million.

Parts coming out of the draw-forming press require further processing, something that the Prima laser cutter provides. The $780,000 Prima laser was built in Italy and acquired through the company's U S office in Farmington Hills, Michigan.

Reading purchased the laser because of its ability to cut parts in all three dimensions. The five-axis robot is programmed to move the laser through its cutting routines. The laser travels, immediately above the surface of the three-dimensional parts, trimming away the flash that results from stretch- forming and cutting any holes that may be required.

The Prima laser can cut steel, aluminum, stainless steel, and plywood. Reading uses it to produce sheet metal parts and blanks with all notches and holes cut. It does so with accuracies of ? .002".

Dueling Lasers

The Prima laser was purchased exclusively for the Aerotech service body and only recently went into service. However, Reading also has a Bystronic 4020-2 laser cutter that has been in service since 1994. The Bystronic laser is designed to cut parts from flat sheet, rather than to perform the three- dimensional operations for which the Prima laser was designed.

Reading bought the Bystronic laser for consistency and inconsistency-consistency because it produces the specified part with high levels of precision, and inconsistency because of its efficiency in fabricating parts for one-of-a-kind bodies.

"The laser is great for single runs," says Dick Gordon, executive vice-president. "To produce special parts, we used to have to shear and measure, bend and notch. All of this makes for significant setup time for our plant equipment. Now we are able to produce drawings in the engineering department and send the data to the machines. We get quality production, even for single runs."

At first we wanted to buy a turret press to produce special bodies," Perlman recalls. "But the hard tools that turret presses use were a problem. We needed a machine that was flexible and easy to program."

Lasers Versus Plasma

Reading also considered the purchase of CNC plasma cutting machines. Perlman cites a series of advantages of lasers for Reading's operation.

• Accuracy. Reading wanted a cutting system accurate enough to burn rivet holes. Perlman says even high-definition plasma systems could not match the precision of a laser for this application.
• Speed of positioning. The Bystronic positioning system moves the laser into position at speeds of 4,400 inches per minute.
• Versatile cutting. The narrow heat zone of lasers is an advantage when cutting thin materials. In addition, lasers can cut nonmetallic materials. For example, plywood liners that some customers request are cut with the Bystronic laser.

Despite a belief that lasers were slow machines suitable only for low-volume production, Reading began researching the ways that lasers are utilized in job shops.

The Bystronic laser can process between 15,000 and 20,000 pounds of material per shift," Perlman says. "Yes, we can cut out a door from coil in 2.5 seconds using other methods, compared with 22 seconds on a laser. But the volumes are no longer there to support the faster production times. The move these days not only is to just-in-time production, but also to high levels of custom specifications. Instead of seeing how fast we can fabricate a single part, we are producing kits from a single piece of steel. Nesting programs make it easy. When we first went to computerized nesting programs, we would second-guess the results. We figured there had to be a way that we could get more parts out of a sheet than the computer could. But the computer was right."

Preconceived Ideas

Reading has disproved another preconceived idea: that lasers are high-maintenance pieces of equipment. Alignment of lasers has been a problem in years past. But in spite of its flying optics (the material stays in place while the laser head moves) the Bystronic laser has a good track record. The machine runs 24 hours per day, six days a week. Yet it can operate for nine months without having to be realigned, Perlman says.

"It's better to keep the laser running," he explains, "You have to go through a five- to 10-minute shutdown cycle when you turn it off and another five- to 10-minute warm-up period. The laser contains a turbo that rotates at 40,000 rpm. At speeds like that, a laser is not something to turn off just because it's time for lunch."

Reading turns the laser off Saturday night and starts it again Sunday night. Virtually all of the "on" time is spent running at full power. Although thinner materials such as 20-gauge steel can be cut with the laser set at low output, Reading prefers cutting everything at high output in order to run the laser at full speed.

Sophisticated fabrication technology in the plant requires up-to-date equipment and processes in the engineering department. Upgrades that Reading has made in recent years enabled the engineering department to be ready when the new lasers and draw-forming press arrived.

Electronic Engineering

The company recently implemented full CAD and CAM capabilities. Drawings for new or modified bodies and parts now go directly from the computers in the engineering department to the computer controllers of the machine tools. To do this, Reading has acquired new computer hardware and software. The company also has expanded its engineering staff from three people to eight.

"Some people might have the idea that computer technology is supposed to save time. They might wonder why we added both people and technology to the engineering department," Perlman says. "The advantage of doing it this way is that we are doing more and more of the work up front-not on the plant floor. With so much of the work already done, all the machine operator has to do is type in a part number."

The labor savings in the plant have been apparent. Reading has trained and reassigned a number of former fabrication department employees. The company has found new jobs in the plant for them as the CAD/CAM system assumed more of the load.

Reading has found the ease of implementing CAD/CAM varies by machine. Because of the larger number of variables to control, press brakes are more difficult to program.

Among the variables: bend angle, bend sequence, tooling selection, material thickness and type, die shimming, backgauge finger height, backgauge finger spread, backgauge travel, and determining how fast the sheet can be formed without causing the material to whip.

"Without computer controls, the operator must regulate these functions manually." Perlman says. "He may have to make all of these adjustments to bend just a single special part. but the DNC controller does it all in seconds, interfacing directly with the special engineering office system and following the department's instruction set."

Reading recently purchased an 18-ft, 400-ton Pacific press brake that enables the company to produce bodies up to 192" long without having to splice material. The six axis controller regulates ram height, the backgauge, and the position of the fingers. The press brake offers automatic crowning, a feature that anticipates the amount of tonnage required and then compensates for that force so that the bend is straight.

"It's possible to buy a press brake and use only 10% of the machine's capability if you don't program it in a CAD/CAM office and away from the shop floor," Perlman says.

The lasers came with their own CAM software that converts AutoCAD's DXF file format into the lines of code needed to program the machine.

"We stayed with the Bystronic software as a post-processor," Perlman says. "Some third-party software may bridge some of the language gaps between AutoCAD and the Bystronic software. But bringing in a third party muddles the issue of accountability. If something goes wrong, who is responsible?"

Cutting Out Paper

The CAD/CAM system helps Reading produce special bodies more efficiently. Instead of an extensive set of drawings kept in three-ring binders, Reading can process requests for special engineering electronically. Those in the special engineering department download AutoCAD drawings from the network server located in the main engineering department.

The system has substantially reduced the amount of paperwork. Now the engineering department supplies the plant with two basic items-a multiple-part shearing order and any cutting lists for structural steel.

When steel blanks arrive at the laser, the laser's computerized controller pulls up each parts drawing from the special engineering server-by order number. The controller automatically sets up the laser and produces the specified parts.

The new plant equipment has significantly reduced the need to shear metal. "We do very little shearing now. Our idea is to use a coil line for high-volume cuts and the lasers for low volume," Perlman says

One example of a high-volume part is shelving. Reading now uses an Ardcor F1O Panel Mill to produce shelves. The 16-pass roll-former can change widths at the push of a button to produce any of the four standard shelf widths that Reading offers. For lower-volume fabrication, Reading has been using the Bystronic laser. It cuts a wide range of components for the traditional service body design, including doors, bulkheads, and partitions.

"We still use the shear on parts that are nothing more than a straight cut" Perlman says. "Our rule of thumb is that we want to use the laser to cut out any part that has some detail such as notches or holes."

The Bystronic laser even produces parts that primarily are cut elsewhere, Perlman cites the instance where a service body has an odd number of doors. The laser can produce the part with virtually no setup time.

Manufacturing the Aerotech

Reading revealed the Aerotech to its distributors in late October. The company is producing its first batch of orders that it received at that special meeting. The company currently is gearing up its production line with a plan to start regular production in February.

"We plan to do a lot of subassembly work," Perlman says. "Assembly will go fairly quickly because of all the preliminary work that will go into the body before it ever gets to the assembly line."

One of the striking characteristics of the line Reading already has set up is its reliance on spot welding. Some arc welding will be performed, but Reading wants to use spot welding to assemble the Aerotech. Spot welding provides several advantages:

• Corrosion protection. The Aerotech is made of galvanneal steel. The spot welds minimize damage to the protective coating of the steel.
• Weld dressing. The spot welds will not need grinding. This saves additional time by not requiring the application of any coating to replace the zinc coating where the weld was ground.
• Labor advantages. Spot welding does not require the same high levels of skill as arc welding. This reduces training time.

Looking Ahead

Initial output from the Aerotech assembly line was expected to be delivered in December. While the cost to the distributor will be higher than standard service bodies, Reading management estimated that the cost of an Aerotech service body would be only slightly higher than its traditional design. Distributors should save installation costs because of the work Reading will do at the factory, primarily with the fuel fill system ready to be hooked up and the lights already in stalled. These savings can be used to partially offset the higher price Reading will charge for the Aerotech.

"After we showed the Aerotech to our distributors, they ordered about twice as many as we anticipated," Dick Gordon says. As of November 11, Aerotech production was sold out through January.

Reading will build the Aerotech in three lengths: 102", 110", and 134". The 102" model is offered either 79" wide for single-wheel chassis or 92" wide for trucks with dual rear wheels. The 110" and 134" bodies are 92" wide only.