Shop Solutions: CNC Lathes Give Cylinder Manufacturer A Big Lift
Godwin Manufacturing (Dunn, NC) is one of the largest manufacturers of dump, platform, and rollback truck bodies in the country. The company also manufactures various styles of hoists, hydraulics, and other related equipment used on the truck bodies.
Its founder Pat Godwin is Dunn, North Carolina, through and through. He grew up just six miles (9.6 km) from what is now his company’s headquarters. He and some friends built his current house just down the street from the main plant. He has a civic pride not seen much in today’s entrepreneurs. He also has an unrivaled work ethic. Always known as a workaholic, Godwin says he has backed off to part-time today. He only works from 6 a.m. to 6 p.m.
Pat Godwin started the company in 1966 with no formal training in the design and engineering of truck bodies. “We were a farming family. Always have been. My brother needed a dump truck, and we couldn’t afford to buy one so I just figured out how to put one together. In the beginning, I had to run the electrical cord from the backyard through the kitchen window and pull out the electric stove plug so I could plug in the cord for my welder.
“I’ve always been creative and inventive. Building that first truck body in the backyard of our house in 1966 was really the start of my business and it just grew from there,” Godwin remembers.
A year later, a friend allowed Godwin to use an 80 × 80' (24.3 × 24.3-m) building to continue his work. Within two years, Godwin had grown the business and moved to the first building at his current location on Route 421 in Dunn. Since then, additional buildings have gone up as the business has grown and, today, Godwin Manufacturing stretches over 750,000 ft2 (69,677 m2)—and that is just the Dunn facility. The company, now part of the Godwin Group with two plants in North Carolina, and plants in Kentucky, Ohio, and Puerto Rico, employs close to 500 people.
When Champion sportswear vacated its large plant in Dunn a few years ago, Godwin saw an opportunity. At the time, he was purchasing the hoists for his dump trucks from other companies. But Godwin, who claims to have a photographic memory for how things are built, believed that he could produce these hoists himself.
After about a year of research and experimentation, Godwin was ready to get into the hoist business. Keeping the Champion name, he christened the plant Champion Hoist and Equipment. Like everything else that Godwin has started in his life, he didn’t go half way.
“At the start, we were just making the frames but not the cylinders. A year later, we were making the whole thing. I quickly realized that the greatest potential for growth for the entire company was with the Champion Hoist and Equipment business.
“Nobody can compete with our quality and pricing,” says Godwin. “The only thing we had to improve upon was our delivery. We were just not making the product as fast as we needed to for our growing business.”
Godwin had been manually processing tube and bar stock for its hydraulic cylinder bodies and piston rods. While quality was not the issue, the time it took to saw-cut material and manually load machines for production was unacceptable to meet growing customer requirements.
Godwin explored a number of solutions and finally settled on two Bardons & Oliver Inc. (Solon, OH) CNC hydraulic component-manufacturing systems. Godwin was introduced to the machinery by the Bardons & Oliver distributor, Davis-Taylor-Forster Co. (Richmond, VA) and its president David Lucas.
Godwin purchased a Bardons & Oliver ISC 350 to machine complete and cut-off piston rods to 3.5" (88.9-mm) OD, and a Bardons & Oliver 2SC 850 to produce complete cylinder bodies to 8.5" (215.9-mm) OD, and dedicated a separate bay in the Champion plant solely to the two systems.
Materials, which include chrome-plated piston rod bar stock and honed steel DOM (drawn over mandrel) cylinder body tubing, are delivered in 26' (7.9-m) lengths. Both machines allow material to be magazine-loaded. The material handling system automatically indexes each new tube or bar into the spindle. The leading end is trimmed, parts are machined complete, and are then carried out of the cutting area to a discharge ramp. Remnant material ends are discharged automatically. Only one operator is required to control each system.
All parts are finished complete, including threads on both ends of the piston rods, if necessary, and any drilling or milling that may be required. Parts are ready for assembly upon exit from the cell.
The 1SC 350 is capable of making complete piston rods to 3.5" (88.9-mm) OD × 124" (3.15-m) long. The 2SC 850 is capable of machining cylinder bodies from DOM tubing to 8.5" (215.9-mm) OD × 124" (3.15-m) long. Not having to saw the rough blank and handle the parts in and out of a CNC lathe reduces the number of operators, reduces the number of machines required, and speeds cycle time considerably. Also with less handling of the material, the parts are not scratched or dented, reducing scrap, especially on the chrome-plated rod material.
Bardons and Oliver, which has developed the process for machining rods and tube bodies over the last several years, has modified and refined it to meet the needs of customers making this type of product. All material handling, tooling, and programming are customized to the exact product requirements. The entire system is built and tested with the customer’s material prior to shipment. Upon installation, the machines are ready to run those same parts again, reducing the learning time for the customer and ensuring a fast start-up.
To say Godwin is pleased with the results would be an understatement. Manufacturing times have been dramatically reduced. “The consistency is fantastic. Even though our quality was OK the old way, this computer-operated equipment brings a consistency to the operation we had just not seen before,” Godwin says.
“We’ve cut our lead time from 12 weeks to seven weeks,” notes Godwin. “But I’m still not satisfied. My goal is to get our lead time down to four weeks max.”
With steel prices so volatile, Godwin is not worrying about if or when he is going to be able to get his raw material. Godwin believes in keeping a substantial amount of raw material in-house to meet demand. “I could build 1000 truck bodies with the inventory I have right now. Getting material has never been a problem for us. When you’re a big volume purchaser and you pay your bills on time, the raw material manufacturers take good care of you.”
Pat Godwin has high hopes for his hoist manufacturing business. He knows that shorter lead times, greater efficiency, and outstanding quality are required to meet increasing demand. He plans to do whatever it takes to continue to keep Godwin in a leadership position in that market.
Single CNC Controls Large Creep-Feed Grinder
Less than three years after opening its doors in Orangeburg, SC, aba z&b USA Inc. is already making its mark on the US surface and profile-grinder market.
The company, headed by President Leonard Cody, is the US operation of aba z&b Schleiffmaschinen GmbH, based in Reutlingen, Germany. Its mission is the in-house rebuild and field service of existing machines, as well as new machine sales, installations, and spare parts fulfillment for aba z&b grinders.
The company’s machines are used by a broad spectrum of American companies, including manufacturers of automotive torque converters, linear guide rails, heavy construction machinery, aircraft engines, oil pumps, compressor shafts, and other large components, as well as moldmaking and tool and diework producers.
In one installation, an aba z&b PSM creep-feed grinder has been installed to do deep- profile creep-feed grinding on cold-rolled and forged steel parts for undercarriage links on a large piece of earthmoving equipment.
Said to be one of the most powerful machines of its type in the world, it has a working length of 1000 mm, grinding width of 550 mm, and grinding height of 550 mm, but was readily integrated into a workcell at the customer’s location due to its traveling column design and small footprint.
An indexing worktable with two workpiece clamping fixtures allows simultaneous load/unload and grinding operations. Linear guideways and ballscrew drives control motion for the main X, Y, Z axes. The overall motion control of this giant grinder is performed by the Siemens Sinumerik 840D CNC with digital drives and motors that allow free contour programming for interpolation- grinding applications.
“This single CNC-controlled grinder replaced a machine with three different processors and operating systems. The customer is realizing savings in setup, training, programming, and maintenance time,” Cody says.
“Between our support from aba z&b and that of Siemens, the time-to-production on these workpieces has been significantly improved, as has the overall part quality and cost-reduction scenario,” Cody says.
The tale of the tape tells why. On this large capacity aba z&b creepfeed grinder, a 1750-mm diam worktable has two workpiece clamping fixtures, each with a qualified surface of 900 × 600 mm and maximum load capacity of 2000 kg.
The X-axis longitudinal movement of the wheelhead column is run by a Siemens CNC-controlled electromechanical drive system with stick-slip-free high-precision linear guideways to guarantee the highest possible positioning and repeating accuracies.
The Y-axis vertical movement of the grinding wheelhead is performed by a variable AC motor and ballscrew, in antifriction guideways for accuracy even in small downfeed increments. The maximum achievable feed rate is 3000 mm/min. The Z-axis transversal movement of the wheelhead column is run by a Siemens digital AC servomotor package with resolution to 0.0001 mm.
The CNC itself features PC-based continuous path control, with an integrated Siemens Simatic S7 PLC and Safety-Integrated software for monitoring all feed rates and axis positions.
Cody also says that aba z&b utilizes Siemens controls and drive packages as OEM components on most of the firm’s various grinding and surface finishing machines.
Borescopes Make Quality Portable
General Automotive Manufacturing Co. LLC (GAM; Franklin, WI) has improved quality control using borescopes to decentralize visual inspection.
GAM produces machined metal parts used in fuel systems, hydraulic assemblies, brake systems, and gas and diesel engines for such customers as Caterpillar, International, Mercury Marine, Stanadyne, Cummins, Actuant, and Sheppard.
General Automotive, which has been in business since 1950, specializes in machining components from steel (carbon, alloy, and stainless) and aluminum (from bar stock, cast, or extrusions). Its range of expertise, however, means that General Automotive handles all types of components and materials—from gray iron and ductile iron castings to stainless steel forgings. It can provide the fixtures, machine tools, and tooling for machining even very complex components.
The company uses the same machining processes for products throughout a wide range of material, heat treat, plating, and geometric shape and size requirements. In addition to the traditional manufacturing processes, General Automotive also offers in-house honing, lapping, ECM, glass beading, assembly, and testing of customer products.
The need for a portable inspection system arose when General Automotive found burrs and other part defects in some instances that its manufacturing team had not detected before the parts were final inspected by the quality department. The result was that General Automotive had to reprocess “blindly” because it couldn’t “see” the defects at the manufacturing-cell level. This reprocessing was expensive and time-consuming.
The problems presented by burrs, sharp edges, and other defects were obvious. “If you have sharp edges or small burrs, they can erode and eventually clog a system, preventing it from working properly,” explains Quality Manager Gary Kosterman. “That’s especially true in hydraulic and fuel systems, which have extremely small openings that can become clogged.”
The conclusion was also obvious: without a more effective inspection process, GAM would continue to spend more time and money than necessary to undertake the vital containment of defects.
General Automotive wanted to do several things. It needed to find inspection tools that could be used inside deep bores and in small-diameter holes. It also needed to report defects and process problems much more quickly to manufacturing teams in order to ensure no incidence of defects and meet its promise of 100% on-time delivery of orders. In addition, the company wanted a tool that it could use both in the quality lab and on the manufacturing floor.
General Automotive’s need went deeper than just satisfying its customers. The company is committed to a “zero-defect” philosophy, even empowering employees to prevent shipment of product to customers if there is any quality concern. Finding a solution to the problem at hand was imperative.
To assure the success of its zero-defect and on-time-delivery quality policies, General Automotive’s quality engineering and metrology teams worked together with supplier partner Gradient Lens Corp. (Rochester, NY) to find a solution. Gradient Lens had developed a patented relay lens design, allowing the production of a high-quality line of portable borescopes, called Hawkeye Precision, that can be used anywhere in a manufacturing plant.
The Hawkeye borescopes’ lens systems are made with chemically treated glass that requires fewer lenses in each scope, reducing the cost of manufacturing the borescopes. According to Kosterman, the borescopes fit into multiple workcells where necessary. Each cell, which could, for instance, include a lathe, machining center, and gundrill, is a self-contained manufacturing team that includes a visual-inspection station.
The inspection stations are equipped with a Hawkeye borescope, a portable or fixed light source, and often a video system (with camera and monitor) connected to the borescope. The system allows operators to view part images on screen rather than through the scope, which reduces eye strain for operators who might spend a good deal of their day visually inspecting components. In addition, the monitor provides a larger viewing image, which makes detecting imperfections easier and group-viewing possible.
More important, the system provides immediate detection capabilities at the point of operation, and allows containment of defects early in the manufacturing process. For example, if a gundrill operator receives a part from the machining center and detects a bad surface finish or large burr in a deep hole produced at the machining center, the gundrill operator can immediately raise a red flag to contain the problem.
“This cell concept versus batch process also allows our operators to have direct input in process improvement,” Kosterman says. “We’ve learned that borescope visual inspection is as important to our manufacturing and quality processes as some of our metrology procedures.”
Although the borescope’s primary function is checking machined parts, engineers also use them to diagnose the cause when an assembly-line machine is having trouble. General Automotive engineers have found that the borescopes save them time and labor, as well as giving them the accurate images they need. Ultimately, the Hawkeye borescope gives the company a cost-effective way to continually increase quality standards without slowing down production.
“The Hawkeye borescopes help with our mission of 100% on-time delivery because we can use them for many different kinds of inspection on the floor, instead of having to take a component into a lab for inspection,” Kosterman says. “Early detection,” he adds, “is key. Containment is easier, as is changing the manufacturing process when we need to.”
This article was first published in the June 2006 edition of Manufacturing Engineering magazine.