Shop Solutions: Taking Risk Out of Oil Industry Machining
Joey LeRouge has followed a familiar path in starting his own company, graduating from his own garage to a fully equipped 9200 ft2 (855-m2) manufacturing facility located in Broussard, LA.
While employed at a well-head company, LeRouge started High Tech Components in 1987, distributing highpressure gate valve parts to oil drillers. He relied on local machine shops to supply the manufacturing. As his business grew, however, suppliers were unable to keep up, so he bought a manual lathe and started making parts himself. The business continued to grow in a new facility, but cycles in the oil industry made business growth unpredictable. To flatten the ride, LeRouge turned his distributorship into a job shop.
By late 2001, High Tech had several manual machines, three CNC machines, and 20 employees in its facility, where it faced new challenges related to programming. The CNCs had to be programmed manually, making complex parts cumbersome to program. In addition, the chief programmer planned on leaving.
For the shop's next phase of growth, LeRouge focused on NC programming. Because his shop was far from industrial centers where assistance might readily be available, he looked for CAM software and chose GibbsCAM's Basic Milling from Gibbs and Associates (Moorpark, CA) for its ease of use and popularity locally in the Lafayette parish.
A key hire in early 2002 was made when John Johnson, a recent mechanical engineering graduate, joined the company. Johnson was trained in shop operations, including NC programming, which would become one of his main responsibilities. Because the CNCs had conversational controls, the CAM system was mostly left unused until two years later when the shop purchased a CNC mill with a nonconversational Fanuc control, which presented its own kind of challenge.
"That's when the software came in handy," says Johnson. "I had already taught myself to do basic milling with GibbsCAM, so we got that mill up and running fast, without having to learn that control, and we started to rely on the software for 2.5-axis milling."
Things changed again three years ago, when a prospective customer approached High Tech Components with a more complex part, a universal casing elevator slip, asking for a low price. Seeing the prospect as an opportunity for much greater business, LeRouge took the risk and accepted the challenge.
The universal casing slip is so called because it is used in various applications within the casing elevator, an assembly used by drill rigs for lifting, lowering, and applying torque to pipe. The elevator is a family-of-parts assembly that High Tech produces for various oil drilling customers. Its main component is a round bowl, with a large outer diameter and tapered internal diameter. A dozen parts fit within and around the tapered ID, with outer radii perfectly matching the ID's taper.
Slips are inserted within the bowl, together with dies, which have an extruded-dovetail shape on one side, and grooved teeth on a radius to fit specific pipe diameters on the other. When these internal parts are hydraulically lifted or lowered, they open or close onto the pipe, releasing or gripping it. Different configurations perform specialized functions, some to lift and lower pipe, others to tighten and loosen connections, while others do both.
"With my limited experience, the part did not seem like something we could make easily," admits Johnson. "We tried six or seven different ways to make it, using fixtures, conventional methods, and custom tooling, exhausting every option."
High Tech had not moved beyond the 2.5-axis Basic Milling GibbsCAM software, so the part's radiused cut on a taper required custom tooling. However, none of the setups were sufficiently rigid because the parts were supported with dovetails. "It was a complete nightmare," Johnson says. "After all that trouble, we purchased the GibbsCAM SolidSurfacer and Advanced Mill modules, which gave us many more options for tackling that part."
They had tried making the part with 2.5 axis, in four operations. Advanced Mill and SolidSurfacer allowed using a fixture on a vertical mill, and doing it in four-axis and two operations, but this lacked rigidity, so they returned to 2.5 axis with a different setup.
By then, High Tech had received a big blanket order from the customer. For efficiency, a setup was developed to allow loading raw stock and finishing the part with four operations in a single cycle on one machine. "The new software modules easily facilitated the various approaches," says Johnson.
With the earlier process of multiple setups, High Tech would run hundreds of parts through the first operation, then set up to run the second, and on through the fourth. At month's end, they would have an inventory of unfinished parts, but without completed parts, there would be no payment. The newer, single-cycle process enabled making a finished part with each cycle, which provided payment for all production work at month's end, leaving no inventory of unfinished parts. "It wasn't the most productive way of making large quantities, but we were paid monthly," Johnson says. "and we did that for a long time."
Then orders for similar parts of different sizes were received, and High Tech used the same setup and programming methods, with all the flexibility that the software provided. They didn't see those parts again until a year ago, by which time they had purchased four-axis horizontal mills, which provided opportunities for increased efficiency.
Advanced Mill and SolidSurfacer software made programming and indexing in four axes efficient and helped reduce cycle times. Furthermore, the software's solid modeler enabled Johnson to model the exact stock and tooling to be used, so he could verify toolpaths and check for uncut material, gouging, interference, and collisions.
With four-axis machining, four slips at a time are run, one on each side of a tombstone. The irregular stock has five plasma-cut sides at different angles. By accurately modeling stock in GibbsCAM, and dynamically rendering the toolpath with the software's Cut Part Rendering, he ensured proper machining and saved a lot of time in program prove-out.
"The software provides many ways to set up for toolpath rendering and collision detection," Johnson explains. "The rendering records exactly where a collision occurs, so you can fix the problem without stepping through the entire program. It's especially useful for long programs with many tools and operations. I use Cut Part Rendering for everything, and I won't put a program on the machine without it."
Johnson says there are multiple features of the software that have made efficiency easier to achieve, not just for the universal slip, but for many other parts High Tech has made since first taking a risk to gain a large customer. "When we had the final 2.5-axis method running well, we finished six parts a day. With the horizontal mill, we get 20 or more."
Frank's International has become the shop's largest client among many, which include Halliburton, Wood Group Pressure Control, Weatherford International, and Pathfinder Energy Services, all oil drillers. According to LeRouge, the shop is now the most diverse in machining capability in the region, perhaps in the whole state. He has invested in training his people in management and operations, and High Tech will soon become the only Louisiana shop with an apprenticeship program.
Operating in three adjacent buildings, High Tech has grown from 28 employees to over 120 in three years, and from 6 to 21 CNC machines, including several four-axis mills, a five-axis Okuma, and a nine-axis Daewoo MX2500 ST multitasking center with two live-tooling turrets and two spindles. All machines are driven by five seats of GibbsCAM on a network. The company employs ten NC programmers of various levels of expertise. Johnson says that over 99% of all these resources serve oil drilling companies.
Within months, High Tech will be taking delivery of three new vertical lathes, in part to accommodate a customer that wants parts with an 80" (2-m) diam. To house the additional equipment and facilitate growth, the shop is adding 30,000 ft2 (2787 m2) with the construction of another building.
LeRouge attributes a good part of success to technology. "It has been challenging keeping up with technology," he says, "but Gibbs and Associates has been a great partner and an alliance that works very well. They provide a common interface for every machine we choose, and allow adding the modules we need as we continue to grow. While John has become a first class, top-notch programmer, I know the value of GibbsCAM. It helps us expand and stay ahead of everybody else."
Cutter Prevents Part Liftoff, Doubles Output
How often have you throttled back on the milling rate for fear of workpiece liftoff?
"Liftoff is a good thing in the aerospace business, and out on the launching pad, but not here on the shop floor," explains Ron Newsome of LT Enterprises (LTE; Fairfield, OH). He should know. He's a programmer for the busy aerospace and defense contract machining shop.
Newsome recently faced exactly that dilemma on a hard-to-fixture military hatch retainer milled from solid 4140 steel hardened to RC 33. His solution increased milling speed on that part by two and a half times, but it also led to a projected 40% plantwide reduction in milling costs, even on the easier-to-machine parts.
Previously, Newsome ran the retainer part a bit slowly so the part wouldn't pull out of the fixture because of the cutting forces. LTE was happy with how the job was running, until Tom Craze of Ingersoll Cutting Tools (Rockford, IL) suggested a better way during one of his weekly walk-throughs in July 2008.
Craze suggested the brand-new Ingersoll EVO TEC milling cutter, which features a free-cutting geometry pressed into a tangential insert body. "Tom was sure we could run faster with no part liftoff. He has been right before, so we decided to give it a try," says Newsome.
The LTE job represented one of the first applications for Ingersoll's EVO TEC family of milling cutters, commercialized only a few months earlier. It includes face mills and end mills that use the same inserts, and combine the best elements of tangential cutter design with high insert rakes, secure seat pockets, and robust edge design.
Founded in 1982 as a real mom and pop shop, LT Enterprises today runs 24/7 in a 40,000 ft2 (3716-m2) plant with 50 employees. Their ISO 9001:2000 air-conditioned facility specializes in precision contract machining and waterjet cutting for aerospace, medical, and military markets.
LTE produces about 12,000 of the hatch retainers annually on CAT 50 50-hp HMCs in 400–500-piece lots every few weeks. Although the workholding fixture provides four-point clamping, the part is L-shaped with a slender cross section at some points. About 60% of the original stock is machined away, severely limiting the choice of clamping locations.
"As the operation progresses, the pullout forces move around and shift in direction," Newsome explains. "Some of them are twisting forces because of the L-shape. Liftoff aside, the unsupported slender sections are prone to vibration during the cut." The problem was so serious that Newsome even considered sequencing between two fixtures to get a better grip in the later stages. In the end, he opted to grip the part once and just run slower.
The original practice was to mill at 26 ipm (660 mm/min) at 450 fpm (137 m/min) and 0.250" (6.3-mm) DOC with a 3" (76-mm), five-flute Ingersoll V-MAX face mill. "This is a positive-positive face mill that at the time would qualify as free cutting in anybody's book," he says.
Craze thought LTE would do better with the just-released EVO TEC face mill, largely because of the more aggressive pos-pos geometry, thicker insert cross section, and secure seat design. So he brought in a sample for a test run.
They first ran the new cutter at the same settings as before, and immediately could hear how much more smoothly it cut. Next they gradually ramped up the feed to 38 ipm (965 m/min) at 525 fpm (160 m/min) leaving depth unchanged, looking for any warning signs of liftoff. None appeared, so they gradually increased the depth of cut to 0.400" (10.2 mm)—the full limit of the insert. Still no chatter, part distortion, or liftoff. Everything stayed put.
"Although we were cutting more than twice as fast, the whole operation sounded quieter and smoother," says Newsome. "The exact gain in metal removal rate was 2.33:1." The operation also ran cooler.
Not surprisingly, LTE standardized on the EVO TEC for that particular operation. Over time, the retooling also led to more than a doubling of edge life from 17 to 41 parts per edge and improved surface finish, exceeding the 125 rms Mil Spec.
As a result of that single success, LTE quickly standardized on the EVO TEC for nearly all face milling and much of the end milling throughout the plant. "If a new idea succeeds in one place, we'll spread it as quick as we can," Newsome says. "The improvement carried over everywhere, and the inserts are interchangeable between face milling and end milling, and they last much longer. So why not?"
His quick action paid off. Besides the 40% uptick in chipmaking rate, the changeover to EVO TEC mills is projected to reduce the company's milling tool inventory costs by 6:1. LTE machinists took to the new tooling right away. With a single insert that fits both face mill and end mill cutters, there's less chance of error, or risk of stockouts.
Besides the freer-cutting geometry and the inherently stronger tangential design, the EVO TEC features a secure seat pocket design, which eliminates a big source of chatter: insert movement in the pocket. Craze explains: "It provides more contact area between insert and pocket, and uses the cutting force vectors to seat the insert more snugly rather than pull it out. Moreover, tangential inserts need shallow seat pockets, leaving the cutter body stronger size-for-size because less metal is machined away."
"If you look at the numbers, Tom actually sold us an idea that improves things here but means Ingersoll will sell us fewer tools," says Newsome. "He may have problems with his boss back in Rockford, but here at LTE he's a hero."
Software Promotes Toolmaker's Growth
Eccles Tooling Systems has been based in Halesowen in England's West Midlands for over 60 years. Most recently, through investments in software and machine tools, especially large five-axis machining centers, the company has expanded the range of industries it supplies with tooling, prototypes, and machined components.
"Seven or eight years ago, around 95% of our work was for the automotive industry," remembers Managing Director Bob Morton. "We were undertaking projects for most of the leading manufacturers, including BMW, Ford, Honda, Jaguar, Land Rover, Mercedes, Renault, and Toyota.
"Even so, we knew we had to expand into other areas. We had always done a small amount of work in the aerospace industry so we focused on growing that business. It now makes up around half of our turnover. We are also winning projects in the marine and rail sectors."
The latest machine additions to the company include an 8 x 3 x 1.3-m Correa five-axis mill and a 3-m seven-axis Faro arm. In combination with CAD-CAM software from Delcam (Birmingham, UK; Windsor, ON, Canada), capacity of the toolmaker and precision-machining company enabled it to compete by improving productivity and shortening delivery times. By combining the new technology with its traditional patternmaking skills, Eccles was able to provide its customers with faster service at a lower cost, while still retaining a high standard of quality workmanship.
At first, only Delcam's CAD software was used. 3-D models would be created either by importing data from the customer's system or by converting 2-D concept drawings into full 3-D representations. The drawings needed by the patternmakers on the shop floor would then be produced from the CAD models, with all manufacturing done using traditional methods. Following the arrival of CNC machines in 1996, Eccles also introduced Delcam's programming software.
It's often claimed that the automation possible with CAD-CAM and CNC operation reduces employment in smaller companies. Nothing could be further from the truth at Eccles. There, the improved productivity and shorter delivery times made the company more competitive, and so increased dramatically the number of projects it won. As a result, the company more than doubled the number of staff. The size of the site was increased to 30,000 ft2 (2787 m2), following a 25% expansion to house more machine tools.
Additional crane bays were installed to handle a load weight of up to 10 tonnes and to ensure comprehensive coverage of the factory and its machining facilities. As well as the Faro arm, two CMM machines using PowerInspect are also available to customers. The larger of these offers a 3.2 x 1.4-m measuring window, allowing the checking of the components that can be produced on the larger machines.
The company changed the way it used its Delcam software to support its customers. "Like most companies, we started with a dedicated CADCAM office to carry out both the design work and the programming of the machines," Morton says. "However, as we became more confident with the software, we transferred most of the programming onto the shop floor. Delcam's PowerMill CAM software is so reliable that the operators don't need to spend so much time monitoring the machines. While one job is running, they usually have time to program the next project."
Moving programming to the shop floor has given the design team more time for their work with the Power-Shape CAD software. This includes completing models supplied from customers, converting component designs into tooling designs and, most importantly, generating more quotes so that the company can continue to win more contracts.
The reliability of the PowerMill software has also allowed Eccles to do much more "round-the-clock" machining. "We can run projects overnight or even over a weekend with minimal supervision," claims Morton. "Many of the larger parts still need to be produced to fine tolerances. This means longer machining times, but there is still the same pressure for fast delivery; 24-hour shift machining is essential."
The eight large-capacity Correa CNC machines at Eccles have helped the company win larger projects. However, they also increase productivity when machining smaller parts. Because the bed sizes range from 2 to 8 m, they give better productivity by allowing a number of smaller parts to be machined in one setup.
"The flexibility of the Delcam software is just as important for this multipart machining," says Morton. "For example, if we need to make a left-hand and right-hand version of a design, we can program one part and then quickly edit the PowerMill project to produce the mirrored component. Also, we don't have to complete one piece and then machine the next one. We can integrate the toolpaths for several parts into one session and so minimize the number of tool changes."
"Many of the aerospace projects that we are now winning would not be practical without five-axis machining," adds Morton. "We couldn't be competitive with the number of setups that would be needed on a three-axis machine. PowerMill has all the strategies we need to get the maximum productivity from our machines."
The use of five-axis machining also allows complex parts to be produced in fewer setups. "One area where five-axis machining has been of great benefit is in making fixtures," says Morton. "These parts often have undercuts, which used to require three or four setups on the three-axis machines. With our five-axis machines, we can normally cut the same fixtures in one operation. This approach yields significant time savings, as well as being more accurate."
Five-axis operation also saves time when machining sealing grooves into tooling. Seals are needed, for example, to prevent leakage when making molds for foam and to maintain the vacuum in vacuum-forming tools. With five-axis machining, it is much easier to maintain a precise and constant depth in the groove, and so ensure that the seal fits accurately without a lot of hand finishing.
"In the 12 years that we have been using CNC machines, we have watched Delcam grow and seen the software become faster and more powerful," Morton concludes. "We expect our partnership to strengthen further as we continue our expansion."
Rock Machining Stars in Sweden
Archaeologists speculate that Sweden began mining its vast reserves of copper and other ore as long as 1000 years ago, when the excavated metals were first used to make weapons.
Given the country's vast reserves, it was once inconceivable that Sweden's mines would ever close. But eventually they did, as cheaper, more-accessible ore became available to the world's metal smelters. Companies supplying the country's mining industry had to adapt to survive. Many didn't.
Times changed, and the mining industry has long since left Sweden in its worldwide search of lower costs. But one supplier of mining equipment has refused to close up shop. Based in Ludvika, 150 km northwest of Stockholm, in a region that once boasted more than 20 busy iron, copper, lead, and zinc mines, Essverk AB builds custom-made excavation equipment used by road and tunnel-construction companies.
As late as the 1970s, Essverk built mining equipment, until the geology and hard rock forced it out of the global ore markets. The mining industry went in search of lower costs and softer rock. To survive, Essverk turned its hand to developing excavator equipment. Today, the company designs many of its products as custom-made solutions for its customers.
In the northwest—along its frontier with Norway—Sweden is bounded by the Kjölen Mountains. East of the mountain range, the topography descends slowly all the way south to the Gulf of Bothnia. The country lies on a tectonic plate referred to by geologists as the Baltic Shield, made from the oldest rocks in the European continent, and up to 300-km thick. Deep inside this cold geological heart of crystalline and metamorphic structures lies an estimated 15% of the world's uranium deposits.
Beneath the silt left by the ice sheets, the going gets tough, and most of the roads and tunnels built in Scandinavia to access these deposits require extensive excavation work. Construction firms in the region prefer to own their vehicles rather than rent them, so to keep costs down, many demand excavator attachments that enable a single vehicle to complete multiple tasks.
Essverk AB is best known for its Multivip Rototilt device, an innovative piece of equipment that transforms all kinds of excavator and loader operations. With its ability to dig, tilt, and rotate in a single movement, it converts excavators from a simple digger into a versatile platform for a wide range of attachments. The Multivip Rototilt enables work from a static position with great flexibility, while tilting in two directions simultaneously, eliminating the need to constantly reposition the machine.
Demand for the Rototilt is high, so much so that Essverk recently had to re-think and reorganize its machining capacity. Bengt Ericsson, the company's technical systems specialist, explains: "A few years ago, we had our own machining capability, but the industry trend at the time was moving toward outsourcing and its apparent cost advantages. So we adopted the same strategy. In the past few years, Swedish subcontract machining companies have become extremely busy, and the lead times quoted have grown longer. In turn, our own lead time had started to extend; a situation that was unacceptable."
To bring machining back in-house, Essverk began searching for a large HMC well suited to manufacturing small batches of prismatic parts with various drilled and pocketed features. Cost, size, reliability, and support were all criteria thrown into the company's evaluation of options. The eventual choice was an EC-1600 CNC HMC from Haas Automation (Oxnard, CA).
"The specification, together with its performance and the price, represented the best business decision," states Ericsson. "It was also available on a short lead time, whereas other suppliers were quoting months."
The EC-1600 HMC was installed in late 2007 by Haas Factory Outlet (HFO) Edströms Maskin, a company with 60 years' experience supplying manufacturers in the region. The machine has already been put to work machining Rototilt components destined largely for Norwegian customer Nanset Standard AS, a distributor for Hitachi Construction Machinery. Parts are designed by Essverk to Nanset specification.
Rototilt parts machined on the EC-1600 include housings that weigh up to 330 lb (150 kg), lower bodies, upper bodies, and all internal components. In total, 55 different Rototilt parts are manufactured using the Haas machining center, making the most of the machine's 30-hp (22-kW), 50-taper spindle and its maximum spindle speed of 6000 rpm. There are three different sizes of Rototilt model, and components are typically manufactured in sets, using fixtures that are machined in-house, also using the EC-1600. Each fixture presents two, three, or four different parts to the cutting tool, ensuring maximum use of the machine's 64 x 36" (1626 x 914-mm) table.
Cycle times vary from 5 min for the smallest and simplest part to 2 hr for the largest housing. All components are manufactured from various grades of engineering steel, and tolerances are surprisingly tight, ±0.0004" (0.010 mm) in some instances, particularly for parts with bearing surfaces.
Despite the high demands, the Haas EC-1600 has coped admirably, as Ericsson confirms: "Since installation, we've had no rejects whatsoever," he says. "Off-line programming is straightforward using intuitive commands, and both of our trained operators enjoy using the machine."
The company has since ordered a Haas SL-30 CNC lathe, which sits alongside the EC-1600 at the company's Ludvika factory.
"The new Haas machines have helped reduce our lead times and get our production back on track," says Ericsson. "At present, the EC-1600 is running 8 hr/day, but this will be increased shortly, once we have finished manufacturing a range of welded fixtures that will help reduce setup time. We also intend to undertake subcontract machining for local companies. Eventually, the machines will be running 16 hr/day."
As well as uranium, archaeologists believe that the country's ancient rocks also hide the world's largest reserves of gold and diamonds. Mining its own reserves of talent and ingenuity, at least one tenacious equipment supplier will be around for Sweden's next mining boom.
This article was first published in the February 2009 edition of Manufacturing Engineering magazine.
Published Date : 2/1/2009