Fast and Furious

Author Cutting Tool Engineering
Published
October 01, 2011 - 11:15am

5.2 SBCT night at Yakima.tif

Courtesy of General Dynamics Land Systems

Viewed with night-vision technology, an eight-wheeled Stryker vehicle from General Dynamics Land Systems performs maneuvers.

Manufacturers large and small develop strategies to quickly redesign and machine new parts for military customers.

The art and science of war is always changing. In recent years, massive, carefully planned troop engagements have been replaced with small but intense clashes with insurgents wielding simple and improvised weapons at close quarters. As a result, the U.S. military is reorganizing some of its assets into agile, quick-response groups primed for fighting on multiple fronts. 

New and modified vehicles and equipment are required to meet the new challenges, and political and budgetary issues are also an issue. Therefore, manufacturers of parts for the military must maximize their responsiveness and innovation.

“Fast reaction on the engineering front is absolutely essential, because the bad guys are changing their tactics and methods and we need to respond,” said Sonya Sepahban, senior vice president, engineering, development and technology for General Dynamics Land Systems, Sterling Heights, Mich., the U.S. defense industry’s largest military vehicle supplier. Editor’s note: View a video about GDLS’ “fast response” engineering in the HTML version of this article at www.ctemag.com.

Sepahban said GDLS’ continuous improvement efforts focus on speed, agility and responsiveness to ever-changing threats. An example was an effort that began in 2009, as the U.S. moved deeper into Afghanistan with GDLS’ Stryker vehicle. The eight-wheeled, 20-ton light-armored vehicle is a key element in fast-strike ground strategies. It can travel up to 60 mph and 300 miles on a tank of fuel, and has various configurations.

In late 2009, it became apparent that the flat-bottomed vehicles were vulnerable to improvised explosive devices increasingly used by insurgents. “We were seeing threats that were significantly beyond what the vehicle was designed for, and in a very short period of time we needed to have a vehicle that was significantly more survivable,” Sepahban said.

In December 2009, GDLS initiated R&D on vehicle changes to improve survivability. The goal was to supply new versions of the vehicles by June 2011, when a Stryker brigade was scheduled to rotate into Afghanistan. To speed the project, GDLS self-funded early research. “We didn’t get a contract for development until April 2010; from December to April we were working on our own because we had to meet the deployment schedule. Otherwise, the next opportunity was another year or two off,” Sepahban said. 

For the redesigned Stryker, GDLS fundamentally changed the underbelly of the vehicle to a double-V design. The V shapes deflect the force of a blast; two parallel Vs maximize ground clearance, compared to a single-V hull. 

By January 2011, 9 months after the contract was awarded, production vehicles rolled off the GDLS assembly line. The vehicles went into the field in May 2011, a month ahead of schedule and, as of September, GLDS had delivered 200 vehicles, according to Sepahban. Industry experts estimate that the project would have taken 3 to 4 years had it gone through the traditional design and development process. 

Stryker Feb 10.tif

Courtesy of General Dynamics Land Systems

A Stryker vehicle maneuvers in a war zone. 

USA Today reported that in the nearly 2 years prior to the arrival of the redesigned vehicles, the Fifth Stryker Combat Brigade lost 37 soldiers and 239 were wounded. Since the redesigned Strykers arrived, that brigade has not lost a single solider. “That proves the point about how important it is to be agile and responsive,” Sepahban said. 

According to Sepahban, GDLS has long maintained a culture of rapid response to customer needs. Recently, the company has bolstered those capabilities with a process for cooperation and communication that it carries out in a facility called the Maneuver Collaboration Center, or mc2 (see sidebar on page 44).

Flexible Manufacturing

To complement rapid engineering response to the changing demands of the military, manufacturers are finding ways to increase the flexibility of production operations. One of those companies is Oshkosh (Wis.) Corp., which manufactures specialty trucks and truck bodies for customers in the defense and other industries. Its vehicles for defense applications haul tanks, missile systems, ammunition, fuel, troops and cargo. 

Oshkosh employs a flexible, integrated manufacturing system that enables immediate updates for its full range of vehicles. The vehicles are assembled on a LOW-TOW towline system installed by SI Systems Inc., Easton, Pa. The system is a below-floor-level conveyor that pulls the vehicles through a series of workstations. Originally installed in 1982, the system has been expanded and modified several times, not only to expand capacity but also to handle a broader mix of military and large commercial vehicles. 

Oshkosh_050002R_CYMK.tif

Courtesy of SI Systems

A nearly 2,000 '-long LOW-TOW towline system from SI Systems helps Oshkosh Corp. streamline production of military and other large vehicles. The trucks move through 50 workstations, where changes can be made even on a last-minute basis. 

SI Systems originally installed a 1,932 '-long final assembly line that moves at a speed of 9 ipm through 50 workstations. Each vehicle is transported from the start of the assembly process until completion on two dollies that support the front and rear axles. According to SI, the efficiency of the final assembly line prompted Osh-kosh to later purchase additional towline systems for axle frame assembly and engine/transmission assembly. 

“When SI installed the initial towline assembly system, Oshkosh was only building commercial vehicles that had a maximum completed weight of 35,000 lbs.,” said SI Systems President Bill Casey. “As their business changed, new, heavier vehicles were introduced, and military vehicles with armor plate were added to the mix. Today, these vehicles can reach final assembly weights of nearly 100,000 lbs. each. We’ve worked closely with Oshkosh over the years to design and build more robust conveyor components to handle these heavier weights and found ways to cut our delivery lead time in half.” 

Oshkosh developed a proprietary manufacturing management system to complement the towline arrangement. Called ShopTech, the system delivers real-time parts lists, work instructions and engineering drawings to each workstation. Using controls, touch screens and bar code scanners, assembly personnel can access more than 160,000 engineering assembly drawings for all the vehicles Osh-kosh offers. 

QC photos obtained from 10 different inspection points are delivered to all stations, allowing for immediate quality feedback and corrective action. The system is capable of implementing even last-minute changes, including introduction of new models, model variants, engine substitutions, shifts in production volumes, and model discontinuations and restarts. 

Small Arms Response

In the same manner that battlefield conditions prompt upgrades in military vehicles, weapons systems manufacturing is also affected by the changing demands of combat. Chuck Fluharty, president of Apex CNC Swiss Inc., Atlasburg, Pa., said he has had to expedite machining components for small arms. For example, the shop produces a small-arms 303 stainless steel screw part that requires slotting and threading. Part production runs 61 consecutive hours unattended to create 2,750 total pieces with a ±0.0006 " tolerance. Apex makes the parts on a Hardinge ST225 (25mm capacity) CNC Swiss-style machine. 

DSC_1991 copy.tif

Courtesy of Apex CNC

Apex CNC Swiss President Chuck Fluharty in his company’s shop, where small arms parts are produced, including 0.251 "-long 303 stainless steel screws (below).

Apexscrews2.tif
Courtesy of B. Kennedy 

Another part, an 11.635 "-long × 0.750 "-dia. 4140 steel small-arms component, involves threading, slotting, milling and turning in one setup. “Low-cost, quick turnaround is what will help manufacturers grow by supplying the new budget-constrained military and their vendors,” Fluharty said.

Weapon components are also subject to ongoing modifications. “Right now weight is the biggest issue on any of the squad unit-type weaponry,” he said. “We have been involved in some of the weight issues.” That included changing the workpiece material for one component from 4140 steel to titanium, which the shop regularly machines. The key consideration for titanium machining is employing upsharp tooling and modifying speeds and feeds to handle the machinablity of titanium, he noted. 

In addition, the shop recently began to machine magnesium versions of a night-vision scope that previously was made from aluminum. 

Bolt3.psd

Courtesy of B. Kennedy

Machining of this 11.635 "-long × 0.750 "-dia. 4140 steel small-arms component involved threading, slotting, milling and turning in one setup at Apex CNC Swiss. In the interest of lightening the load of soldiers in the field, the shop later machined the part from titanium.

Similar to general manufacturing, tight budgets are forcing the military and its contractors to reexamine inventory policies. Apex was recently asked to bid on machining a tiny firing pin that typically would have been produced by a supplier making a million of them per year. “The customer asked us to bid on quantities of 100,000 and 200,000,” Fluharty said. “That is an indication they can’t just do business the way they used to by ordering large quantities and sticking them in the warehouse.” 

A manufacturer that was making the parts profitably a million at a time may not be competitive at 100,000. “If they were relying on these high-volume jobs for cash flow, and they are not in a position to be more competitive with lower quantities, that puts them in a bind,” Fluharty said. 

Digital Thread

Consolidating and standardizing the flow of manufacturing data also contributes to manufacturing responsiveness. Fluharty said defense industry customers are adopting a “digital thread” approach to handling manufacturing information. In a digital thread, engineering, manufacturing, QC, assembly and modification details are linked by a two-way flow, or thread, of digital data. The thread enables precise process control and can facilitate upgrades to existing components because data is always available. 

IMG_6939 mod.tif

Courtesy of Adept Technologies

Adept Technologies built this custom 5-axis dynamic test rig that enables it to test parts such as helicopter bearings for military customers who are operating under time constraints that make it difficult for them to perform the tests themselves. The machine replicates a rotor in action and can put a part through millions of operating cycles to test durability. 

“Military customers want to be able to send us a file with all the technical data and have us manage it digitally, program it on our machines, inspect the part and submit the inspection data to them in digital form,” Fluharty said.

Such initiatives will influence a shop’s new equipment purchases. “As a small shop, we are orienting ourselves to digitally capture everything we do,” Fluharty said. For example, the shop uses a vision inspection system that captures images and dimensions digitally, but many parts are better inspected on an optical comparator. “We are looking for a new optical comparator that can import a digital file for the part, be able to inspect that part on the comparator, then capture the data digitally and send it to the military.” 

As a result, Fluharty is researching advanced comparator equipment and software. One example is eCAD from Optical Gaging Products Inc., Rochester, N.Y. Available on some OGP contour projectors, eCAD is an electronic overlay package that consists of software and internal comparator hardware and enables use of a CAD model to project a profile tolerance band onto the comparator viewing screen. 

Regarding customer requirements for technology like the digital thread, Fluharty said, “If you don’t have it, you just can’t participate.” 

One-Stop Shopping

According to Chad Fielder, who founded Adept Technologies, Huntsville, Ala., with his twin brother, Brad, in 1995, “the government is looking for a one-stop shop” to maximize responsiveness from a supplier. Specializing in defense manufacturing, Adept has grown to more than 70 employees performing machining, welding, painting, plating, fabrication and engineering services. 

When dealing with a shop that doesn’t have a range of capabilities, Fielder said, a military customer “has to find a second source certified to do paint, somebody else who is certified to do welding. When they come to us, we are certified to do it all in-house. We do things in a week that would take somebody else maybe a month because they have to reach out to two or more different suppliers.”

IMG_8355.tif

Courtesy of Adept Technologies

Adept Technologies says it is the first manufacturer to laser engrave flight-critical parts, such as these UH-60 helicopter components, with unique identification for tracking assets in the Army Maintenance Management System - Aviation. 

Adept makes parts ranging from electronics chassis to missile canisters to flight-critical items for Black Hawk and Apache helicopters. The shop machines standard steels and aluminum, as well as armor-grade materials, exotic alloys and composites.

Familiarity with different materials facilitates upgrading of legacy parts. “The government brings us helicopter parts that are obsolete. We reverse engineer the parts, insert new technology to improve them and make them,” Fielder said. 

Many of the parts represent decades-old technology and materials. The new parts engineered by Adept feature new application-specific materials. For overmold rubber materials, for example, the shop has worked with a silicon manufacturer to produce parts using “a newer material that withstands the sand and abuse they are now getting overseas,” he said.

Some of the legacy work results from funding restrictions. Fielder said defense cuts are halting the introduction of new equipment, so the work focuses on sustaining existing equipment. “They are taking all the old UH-60 helicopters, tanks and Humvees and refurbishing them with newer technology,” he said. “The UH-60 Black Hawks were never intended to fly as long and for so many hours as they are flying, but the military doesn’t have the budget to buy new ones.” Long lead times for new equipment also are problematic. “Right now, if you ordered a brand new Sikorsky UH-60 Black Hawk, it’s 5 years to delivery.”

Time constraints on military customers have prompted Adept to add part testing to its capabilities. “The customers for some of the components that we build for helicopters don’t have the time to put them on a helicopter and test them,” Fielder said. “We built a 5-axis gimbled test stand, basically a CNC machine, which replicates a spinning rotor. You put a component in it, heat it up to 170º and cool it to -160º, and it goes through millions of cycles.”

The Fielders’ keep the shop current with new technology. “We replace our equipment, we replace our software, we stay up with the cutting edge technology,” Fielder said. “Our motto is ‘If you don’t change, you die.’ ” Accordingly, the shop recently purchased several Vertical Center Nexus vertical machining centers and an Integrex 100-IV ST multitasking machine from Mazak USA, Florence, Ky. Fielder said the multitasking machine enhances responsiveness because it takes the place of several different machines and several different setups. It also minimizes human error. “You may be going from three setups to one. If a guy touches a part three times there are two other times he can make a mistake,” he said.

The approval process for new or modified parts consumes time, but Adept has an advantage. Fielder said: “We are lucky that we are in the right location. The Redstone Test Center at the Redstone Arsenal is 4 miles from here, and the Aviation Engineering Directorate testing is also carried out at the arsenal. We BK1b.tif work daily with the engineers and quality leaders there to get a part through the approval process. It doesn’t happen overnight, but we take it all the way through the testing and evaluation.”

As the military reshapes itself to meet rapidly changing threats, it’s clear that manufacturers must also reshape their production strategies to maintain support of U.S. armed forces around the world. CTE

About the Author: Bill Kennedy, based in Latrobe, Pa., is a contributing editor for CTE. He has an extensive background as a technical writer. Contact him at (724) 537-6182 or billk@jwr.com. 

Contributors

Adept Technologies
(256) 851-2932
www.adept-technologies.com

Apex CNC Swiss Inc.
(724) 947-2123
www.apexcncswiss.com

General Dynamics Land Systems 
(586) 825-4000 
www.gdls.com
www.gdls.com/mc2

Oshkosh Corp.
(920) 235-9150
www.oshkoshcorporation.com

SI Systems Inc.
(800) 523-9464
www.sihs.com 

 

109_11_2002.tif

Courtesy of George Dzahristos, General Dynamics Land Systems

Workers in the high-bay area of General Dynamic Land Systems mc2 design and development facility upgrade a combat vehicle.

GDLS promotes responsiveness squared 

Collaborative relationships are a long tradition at General Dynamics Land Systems. As part of that tradition, GDLS President Mark Roualet created and led the development of the company’s new Maneuver Collaboration Center (mc2).

“The cornerstone of mc2 is a strong systems engineering approach,” said GLDS’ Sonya Sepahban. “These vehicles are very complicated; you can’t just change one aspect without it rippling through the whole vehicle. Engineers decompose requirements, design to their specific requirements and roll those design elements back into the overall system design for validation and verification.”

A key element of mc2 is a virtual community, based at www.gdls.com/mc2 and comprised of GDLS engineers and other employees, suppliers and customers, as well as academia and individual war fighters. The open configuration facilitates exposure to nontraditional ideas and suppliers.

On the Web site, members can view opportunities and needs categorized into eight “Technology Thrust” areas of interest, including mobility, survivability, lethality and autonomous systems. Members then can submit solutions for a particular need. Publicly posting needs is “quite a unique behavior in this environment,” Sepahban said. “Of course, needs are presented in a way that is not sensitive or doesn’t compromise safety, but that is specific enough to help channel the innovative solutions and ideas toward our needs. For example, if you make weapons systems, you can go into that area of interest and see what our needs are. Then anyone can submit an innovative solution.” 

There is a rapid-response timeline for suggested innovations. A cross-functional GDLS team immediately evaluates all submissions and informs the submitter within 48 hours if the solution will be considered for collaboration. If it is, GDLS engineers meet with the solution provider within 7 days. Typically, 30 days later the solution is more fully developed through collaboration in the mc2 and may be submitted to a potential customer. When accepted by a customer or otherwise sponsored for implementation, the solution can be included in a new or existing vehicle. “We have a team that does this day in and day out,” Sepahban said. “We are tracking very closely to the timetable.”

Ground was broken for the 22,000-sq.-ft. mc2 facility in Sterling Heights, Mich., in late 2009, and it formally opened in October 2010.

“The center is built around the process,” Sepahban said. “There are meeting rooms for initial contact. Then we go on to an initial assessment that involves brainstorming in tabletop areas. Then we move on to simulation and modeling and more engaged collaboration with the innovator or submitter of an idea.” For that step in the process, the facility has separate labs with the required tools and capabilities. “From there we have a high-bay area in the facility where we can integrate the hardware or software from the submitters into actual vehicles or demonstrators. We call it an end-to-end collaboration environment,” Sepahban said. 
The mc2 process is a combination of speed and discipline. “For example, with the double-V hull for the Stryker, from day one we had a plan, a schedule and the associated costs. We held to it and delivered the product earlier than expected.”

To view a video about mc2, access the HTML version of this article at www.ctemag.com.

—B. Kennedy

Related Glossary Terms

  • alloys

    alloys

    Substances having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

  • bandsaw blade ( band)

    bandsaw blade ( band)

    Endless band, normally with serrated teeth, that serves as the cutting tool for cutoff or contour band machines.

  • centers

    centers

    Cone-shaped pins that support a workpiece by one or two ends during machining. The centers fit into holes drilled in the workpiece ends. Centers that turn with the workpiece are called “live” centers; those that do not are called “dead” centers.

  • chuck

    chuck

    Workholding device that affixes to a mill, lathe or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated. May also be fitted to the machine table to hold a workpiece. Two or more adjustable jaws actually hold the tool or part. May be actuated manually, pneumatically, hydraulically or electrically. See collet.

  • clearance

    clearance

    Space provided behind a tool’s land or relief to prevent rubbing and subsequent premature deterioration of the tool. See land; relief.

  • composites

    composites

    Materials composed of different elements, with one element normally embedded in another, held together by a compatible binder.

  • computer numerical control ( CNC)

    computer numerical control ( CNC)

    Microprocessor-based controller dedicated to a machine tool that permits the creation or modification of parts. Programmed numerical control activates the machine’s servos and spindle drives and controls the various machining operations. See DNC, direct numerical control; NC, numerical control.

  • computer-aided design ( CAD)

    computer-aided design ( CAD)

    Product-design functions performed with the help of computers and special software.

  • gang cutting ( milling)

    gang cutting ( milling)

    Machining with several cutters mounted on a single arbor, generally for simultaneous cutting.

  • inches per minute ( ipm)

    inches per minute ( ipm)

    Value that refers to how far the workpiece or cutter advances linearly in 1 minute, defined as: ipm = ipt 5 number of effective teeth 5 rpm. Also known as the table feed or machine feed.

  • land

    land

    Part of the tool body that remains after the flutes are cut.

  • milling

    milling

    Machining operation in which metal or other material is removed by applying power to a rotating cutter. In vertical milling, the cutting tool is mounted vertically on the spindle. In horizontal milling, the cutting tool is mounted horizontally, either directly on the spindle or on an arbor. Horizontal milling is further broken down into conventional milling, where the cutter rotates opposite the direction of feed, or “up” into the workpiece; and climb milling, where the cutter rotates in the direction of feed, or “down” into the workpiece. Milling operations include plane or surface milling, endmilling, facemilling, angle milling, form milling and profiling.

  • parallel

    parallel

    Strip or block of precision-ground stock used to elevate a workpiece, while keeping it parallel to the worktable, to prevent cutter/table contact.

  • process control

    process control

    Method of monitoring a process. Relates to electronic hardware and instrumentation used in automated process control. See in-process gaging, inspection; SPC, statistical process control.

  • slotting

    slotting

    Machining, normally milling, that creates slots, grooves and similar recesses in workpieces, including T-slots and dovetails.

  • threading

    threading

    Process of both external (e.g., thread milling) and internal (e.g., tapping, thread milling) cutting, turning and rolling of threads into particular material. Standardized specifications are available to determine the desired results of the threading process. Numerous thread-series designations are written for specific applications. Threading often is performed on a lathe. Specifications such as thread height are critical in determining the strength of the threads. The material used is taken into consideration in determining the expected results of any particular application for that threaded piece. In external threading, a calculated depth is required as well as a particular angle to the cut. To perform internal threading, the exact diameter to bore the hole is critical before threading. The threads are distinguished from one another by the amount of tolerance and/or allowance that is specified. See turning.

  • tolerance

    tolerance

    Minimum and maximum amount a workpiece dimension is allowed to vary from a set standard and still be acceptable.

  • turning

    turning

    Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.

  • web

    web

    On a rotating tool, the portion of the tool body that joins the lands. Web is thicker at the shank end, relative to the point end, providing maximum torsional strength.