As sniper fire and attacks on American troops in Iraq continued last October, a U.S. Army sergeant worried about his impending return to active duty on Oct. 11, when he would resume his job escorting supply convoys. Having drawn ambush fire on previous missions, the sergeant, who we’ll call Armstrong, pondered retrofitting some kind of mount on both sides of his Humvee for a .50-caliber machine gun. While struggling to fashion a reliable 180º swiveling design in the forward-repair-activity welding shop at the U.S. Army’s Camp Arifjan in Kuwait, somebody suggested he seek a helping hand outside, in the parking lot.
Armstrong was lucky: A week earlier, his notion would probably have remained just that – a notion. But on Oct. 6, after four years of research and development, the Army deployed a stunning new capability at Camp Arifjan, the equivalent of a M*A*S*H unit for vehicle parts. With the clock ticking on Armstrong’s departure back to active duty, engineering technician Kevin Green got to work inside a portable, state-of-the-art manufacturing center the size of a small mobile home.
A Long Standing Problem
Part failure, an inevitable problem in the life of any hardworking machine, looms as a potential life-and-death concern to the Army – especially when the machines in question are vehicles at the front, such as M-1 Abrams tanks and Humvees. And when the front is the inhospitable desert of the Middle East, where sand gets into everything and the blistering sun pushes ambient art temperatures to a stifling 130º Fahrenheit, the stakes are even higher. Stuck between the rock disabled vehicles and the hard place of transporting and warehousing tens of thousands of replacement parts near the battle lines, the Army stocks a much smaller, just-in-time inventory of spare parts – in most cases, pre-rounded up “usual suspects,” if you will.
“From past war experience, you can predict that part X is going to fail and in what quantity,” says Todd Richman, a mechanical engineer at the Army’s Tank Automotive Research, Development and Engineering Center (TARDEC), located at its National Automotive Center (NAC) in Warren, MI. In a perfect world, only those parts predicted to fail would crack, freeze up or shatter during wartime or a post-war occupation. Of course, our war-torn workd is neither perfect nor perfectly predictable. Un-stocked parts also fail, and it’s time-consuming and expensive to fly them in from the United States, where the Department of Defense’s annual cost of maintaining repair-part invetories exceeds $60 billion. A much better method is to machine these un-stocked parts on an as-needed basis, returning a tank, Humvee or supply truck to service in a matter of hours or days, instead of weeks or months.
Answering the Call
This concept is no longer pie-in-the-sky dreaming. As Richman explains, a four year, $20 million research and development project coordinated by the NAC has delivered a prototype
mobile parts hospital (MPH) with CNC milling capabilities to support the troops in Iraq. In addition, the center is fine-tuning a sister unit that will create parts layer by layer with a laser-driven accretion process.
Working in tandem, says project manager Richman, these units would represent the world’s first such mobile rapid manufacturing system.
The camouflage-painted, containerized module, flown to Camp Arifjan last September, measures 8-ft. by 8-ft. by 20-ft. and weighs 27,000 pounds. Accounting for about 80 percent of that weight is a Mazak 100-SY multi-tasking turning center. The center also occupies most of the unit’s space, leaving just room enough for a chest containing several dozen Valentine VM Modular Tools (in addition to the Mazak’s preloaded 21) and an operator’s workstation. It’s a novel and challenging manufacturing space that skeptics – even Mazak himself – gave a small chance of success. “This has been an R&D project,” Richman stresses. “We wanted to push the technology.”
But pushing that technology also raised a fear. The concern was that a workhorse CNC milling machine manufacturing replacement parts in such an environment would live up to the first word of its designation (i.e. mobile) in untimely, job-ruining fashion, bucking its itenerant trailer about like an unbalanced washing machine in a home laundry room. “We normally advise that the 100-SY be anchored in 109 cu. ft. of concrete, a 15-in.-thick George Yeomane, Mazak’s marketing manager. Designers of the MPH effectively skirted that issue in two ways. First,they added steel l-beams to the base of the unit to help stabilize it. Second, operators backed off on production speed, rather like keeping a Ferrari in first or second gear.
“We learned you have to operate the machine slowly,”explains Stan Kolish, a regional manager with Alion Science and Technology, a prime contractor helping to integrate the technologies on the project. “If we ran at 100 percent of capability, changing tools in less than half a second, it would move that 14-ton shelter all over the parking lot is in. So we operate at about 25 percent.”Tool changes now take maybe two seconds, jobs that would ordinarily take 15 minutes at shop-floor speed now require an extra five or 10 minutes-perfectly fine when the task is a single part or perhaps a handful, instead of turning them out by the thousands.
The size of the manufacturing envelope on the turning center limits the dimensions of what the MPH can manufacture; jobs can range up to about 2-ft. in diameter, and must weigh less than 100 lbs. Should a request from the field call for one of the 500 parts already entered into the database – which is managed by a product-data-management software program called Windchill – the operator can call up two-and three-dimensional views by the part’s NSN identification number, as well complete CNC data and step-by-step operating instructions, on the workstation computer screen.
Help from Home
All part requests are tracked,and if needed be, assisted by a stateside Communications and Control Center in Detroit. The so-called C3 Unit, housed in a futuristic looking two-story module with sliding glass doors, is found inside a former Ford Mortor Company engine plant. Once again a bustling manufacturing center, the facility is owned and run by a local non-profit called Focus: HOPE, which trains the city’s jobless to be machinists while fulfilling orders for the big-three automakers and others. On a recent day, stacked near the C3 module, and not far from a Mazak Integrex 300-IISY and a Vibe Tech de-burring machine, a run of finished engine parts for the 2006 model Cadillac awaited pickup.
Entering the C3 through an ultramodern, dual-sliding glass door is a bit like walking onto a Star Trek set. A pair of workstations worthy of the S.S Enterprise each offer a trio of eye-level flat-screen monitors. Nearby stands the server that links these workstations with its counterpart the MPH, either via a T-1 line, as has been the case so far, or via satellite. If eye contact is necessary, staff can make the connection visual. So far, the MPH is staffed with contractors on rotation from the United States.
“The Army’s trying to decide: ‘Do we want to field it with contractors or soldiers?’” says Kolish, sitting at one of the workstations.” We’re trying to program it so soldiers can operate it. If the part (to be built) is in the database, it’s pretty easy. You call it up, go to the tool list and bring up a picture of the tool so you can see you’ve got the right one, it tells you to hit this button; you hit that button.”
If the desired part is not found in the MPH database of ready-to-run jobs, the C3 steps in. With the engineering support from another subcontracting partner. Cleveland, OH-based CAMP, Inc., the C3 gathers the necessary CNC machine code and 3-D models, and in many cases, will transmit the necessary information bact to the MPH. However, the MPH will not always have the proper raw materials or perhaps the capability to make the part. In such instances, the plan calls for the job to be run by a so-called agile manufacturing cell back in the United States. The shop floor surrounding the C3 here at Focus: HOPE is one such agile cell. Others, each specializing in particular parts, would theoretically be located at various Army sites.
Lasering up With LENS
Also not yet seeing action is the second component of the Rapid Manufacturing System, the sister MPH module to the one already operating in Kuwait. This mini-manufacturing plant houses an Optomec LENS 750 Directed Metal Machine in an expandable, 20-ft. Army ISO shelter.Instead of milling away metal from bar stock to manufacture parts, this 21st century production tool employs a powerful laser to melt powdered metal sprayed from four focused nozzles. Minute layer by minute layer, a desired part takes shape.
Originally outfitted with a 500-watt diode laser, the Army recently upgraded to a 2,000-watt laser, which actually speeds up the manufacturing process more than 10-fold. The newly added, more powerful laser on the LENS is expected to speed up production, trimming the time needed to make a 3-inch-by-1-inch part from 45 minutes to 10 minutes.
While operators learn the LENS module’s new capabilities and characteristics, it marks time in an industrial park in suburban Detroit, sitting in the parking lot of a laser-integration company located. Events in Iraq notwithstanding, Richman projects October 2004 – a year after the Middle East arrival of the lathe manufacturing module – as likely deployment window for the second MPH. Should it indeed head overseas, the LENS manufacturing method would offer some promising pluses in a module, close-to-the-troops application, all stemming from its innovative process.
“You first model the part in the software we have,” explains Richman.”Then slice the model from 100,000 to 200,000 times.”Then, working at the near atomic level, the LENS recreates those slices, adding layer upon layer of laser-melted powered metal – perfect spheres 45 microns in diameter, or as fine as talcum powder. Because a single 5-gallon bucket of powdered metal can turn out the same parts as varied array of cumbersome bar stock, the Army can save on transportation and warehousing costs. “You can also mix powders with this process,” says Richman. “For instance, you could switch to a high-strength steel when you got to the head of a prison.”
While the new characteristics of the second MPH are being defined, the first MPH is hard at work. As of Now. 14, 2003, after about five weeks of service, it manufactured 25 different parts, and 102 parts in all. Among them: angle-bracket bolts for forklifts; a wear bushing destined for a Humvee engine; a replacement shaft shoulder for a palletized loading truck; and the six different components of the swiveling pintle assembly that enabled Armstrong to retrofit machine gun swing mounts on either side of his Humvee.
That job continued late into the night, finishing the parts for Armstrong in time for his next-day return to active duty. In an e-mail report to Richman, MPH technician Green wrote: “The pintle assembly was designed, manufactured and delivered within five hours. The soldier picked up the parts the next morning, installed them, and was on his way to execute his mission – on-time, and with the additional firepower on board his retrofitted HMMWV capable of deterring and repelling enemy attacks.”
As it happened, Armstrong’s retrofitted Humvee did encounter enemy gunfire on its escort mission. The MPH-enabled modification worked perfectly. According to one of the gunners: “It was like spraying a water hose back and forth, hitting all the targets in sight.”
As word spread of Armstrong’s efficacious, potentially life-saving retrofit – and the timely, on-the-spot manufacturing assist from the MPH, the MPH received the first of what promises to be many requests for another such assembly. This time, with these made-to-order, jury-rigged parts entered in the MPH database, the manufacturing will proceed even faster.
One month’s experience behind the lines for a prototype unit, of course, is no guarantee of the ultimate success of this new take on the M*A*S*H concept. But put all the initially manufactured parts together, and a very promising future, if not a movie and TV series, seems more than likely for the MPH.
John Grossman is a frequent contributor to Screw Machined World. Based in Mountain Lakes, NJ, he’s written for Inc Magazine, Air/Space Smithsonian, Inc., and the New York Times Magazine