Shop Solutions: Miller Welding Doubles Down on Laser Processing
It wasn’t too long ago that Brad Miller, vice president-operations, Miller Welding & Machine Co. (MWM; Brookville, PA) was quite cautious about new large equipment installation, and rightfully so. Such major investments aren’t to be taken on lightly. You have to look before you leap is how you might look at it. In all, MWM has experienced 49 years of incremental growth, so its discretion in investment is unimpeachable. By exercising caution, the company has been doing something right. But within the last decade, the pace of change has increased as MWM’s operations and its role as a leading metals contract manufacturer continued to see substantial growth.
MWM has been up to the challenge. From its modest beginnings in 1963, the company now employs nearly 500 people and rests on a combined 500,000 ft2 (46.451 m2) of shop space among its three facilities with an additional 55 acres (22 hectares) of expansion capacity. The evolution from small reconditioning shop to fully integrated manufacturing unit has been punctuated over the years by measured advancement, adding operations piecemeal when necessary, and beginning to integrate into manufacturing in the early 1980s.
As it stands today, MWM is churning out complete fabricated assemblies, covering a complete range of capabilities including laser cutting, metalforming, robotic welding, machining, powder coating, and even mechanical assembly. The components coming out of MWM’s plants are finished and ready to incorporate at point-of-use on the OEM’s production line, primarily heavy construction, mining, and material handling companies.
"Mitsubishi gets credit for inspiring us," said Miller. "I’ve been more eager to initiate new equipment growth thanks, in part, to how seamless the laser and cell/automation installations have been. We have a major new machine tool installation happening right now and are continuing to refine our balance of a skilled workforce and automated capabilities. We did our homework on it, of course, but our experience with our Mitsubishi lasers certainly affected my attitude toward automation, and made us all a little more receptive to the project."
The company’s relationship with Mitsubishi Laser began in 2004, when MWM realized that it would need the accuracy of laser-cut parts to grow its future robotic operations. Without accurate components, you can’t get accurate welds, and robotics requires, above all, precision parts. MWM’s first purchase was a Mitsubishi LVP 3718 with a 4000-W resonator and a CO2 laser-cutting system. As usual, MWM did due diligence on the investment, ultimately finding that Mitsubishi Laser offered a lower operating cost that would pay off over time.
"Having the lasers has helped us eliminate additional operations throughout the manufacturing process. I can’t imagine being in our business without at least one laser. It would be such a disadvantage. You’d be left out," Miller said. "We are able to control our own destiny with our in-house machines, and react much more quickly to the changes in our customers’ demands. Being able to be more vertically integrated as a supplier has been a huge advantage."
The company doubled down on Mitsubishi in 2010, this time adding a Mitsubishi 3015 LVP-45CF with a slightly more powerful R 4500-W resonator. Both machines have 60 × 120" (1.5 × 3-m) tables with the capacity to cut 1" (25.4-mm) thick metal. But MWM didn’t stop there. After all, what good are a couple of super-fast lasers if you can’t keep up with their input and output capabilities?
To maximize productivity between the two lasers and allow them to work in tandem, MWM also implemented the Auto-FlexMS HP system, based on the MSCIII (Multiple Shelf Changer). Individual shelves on this 12-shelf loading system can hold 6000 lb (2721 kg) of material each, so a total of 72,000 lb (32,659 kg) can be in the system at any given time. A full load/unload cycle time is barely more than a minute.
"The pick-and-place tower and loading system are remarkable," Miller said. "The machine transfers the material piece in, cuts it, and transfers it out, enhancing our ability to stay on-time dramatically. I thought it would help, but I didn’t realize how much." Confronted with this happy problem of increased output, all MWM had to do now was prepare operators for a huge fluctuation in part production.
"Our beam-on time dramatically increased, putting us in the 90% range. Honestly, having a cell and two machines with fewer operators, was like having three machines," Miller said. "We ended up having to shift labor from operating the machine to handling all of the components and pieces that were coming off of it. We just didn’t expect the productivity and throughput to increase as much as it did."
Today with substantial automated manufacturing capabilities spanning plate processing, welding, machining, and powder coating, MWM redefined the balance of manual labor and automation. This means increasing productivity without taking on extra labor costs. The lasers operate lights-out, optimizing production time with minimal need for supervision. Regular maintenance ensures productivity stays high and beam-on time is maximized.
"With high technology, it isn’t wise to wait until things break down to have machines serviced. All in all, this makes for a lot of component production," Miller said. "We are growing, and we have to grow at the same pace as our customers. We are the sole provider of many of their components, and we have to find ways to grow with them. We don’t have the option to only do what we’re comfortable doing, which is actually a very good thing. It keeps us pushing forward. You’re either growing or falling behind, and we’re growing."
With the pressure to grow, the modular nature of Mitsubishi’s automation looms large, because it provides the versatility to expand as the business expands. Users can add shelves for additional storage, and additional load stations to run two different materials simultaneously on a two-laser cell. And that all too common limiting factor—space—isn’t much of a problem for MWM.
"Ultimately, our customers expect three things from us. They expect the highest quality parts to be delivered on time to the day, and they want to pay a fair price for these components," Miller said. "As we continue to invest in new equipment, we will develop partnerships that will help us address each of those three requirements. Mitsubishi has become a proven partner by helping maintain those standards with high quality, increased speeds and reduced labor," Miller said. ME
For more information from MC Machinery Systems Inc./Mitsubishi, go to www.mitsubishi-world.com, or phone
Delivers Ultra Precision
Nearly every highly diversified global company makes a variety of products for a host of different industries. It’s what diversification is all about, right? Not in this case. This global holding company and its companies are thriving making a variety of products for a single industry--machine tools, machinery, and metalworking.
Advanced Machine & Engineering Co. (AME; Rockford, IL) is a global manufacturer and distributor of precision machine tool components and metalcutting solutions.
AME’s product lines include production carbide saws and blades, workholding, safety and position-holding devices, as well as power drawbars and spindle interface components, and other precision machine components such as bushings, sleeves, and clamping disks. The company also designs and builds special machines for a variety of industries and provides machine rebuilding, retrofitting, and contract manufacturing services.
Advanced Machine & Engineering has been a supplier of machine components in the US for 48 years with partners and customers around the world and across the US. German and Swiss partners include OTT-Jakob, Sitema, Spieth, and Triag, as well as AME’s sister company, Hennig Inc. AME and Hennig both belong to the Goellner Inc. holding company.
Hennig has been designing and producing custom machine and power equipment protection, as well as chip/coolant management products for state-of-the-art machine tools for more than 50 years. Hennig’s products include telescoping steel way covers, way cover repair services, X-Y shields, folded bellows, roll-up and apron covers, way wipers and wiper systems, telescoping springs, chip conveyors and filtration systems, and machine enclosures.
"When we bought the Studer from United Grinding Technologies [Miamisburg, OH] in 2006, we were looking at two machines that were rumored to be very good," said Sam Schubert, grinding supervisor. "However, if you bought either one you’d probably want to buy a second machine because of the commonality in controls and training issues, and the ability to cross train. If you have a variety of machines, with a variety of different controls, you tend to have operators who don’t want to leave a particular machine, because they’re familiar with that specific control."
Recently, AME took delivery of a Studer favoritCNC cylindrical grinder to provide them with the technology, along with the Studer S40, to grind spindle shafts. Lately AME has been grinding an increasing number of spindle shafts, a job they hope customers will place them on their supplier short list for.
"I consider what we do to be small-volume work. One to five shafts, and then every once in a while a 20 to 30-piece spindle shaft order. Nothing in the hundreds," said Schubert. "Normally the spindle shafts are 8620 carburized and hardened steel. The shafts are from 6 to 50" [152–1270-mm] long, and almost all of them are going to have OD bearing diameters that will be ground on the Studer. The shaft diameters can be straight or they can be tapered. The tolerances on the shafts come from the bearing manufacturers. If it’s 100-mm diameter, we’re going to be held to 0.0003" [0.008 mm] total tolerance on bearing diameters. Some shafts are going to have three, four, five, six or more diameters, plus some shoulders.
"Basically, what we do since all of them are heat treated, is prep them, meaning we will grind the centers. Then we rough grind and grind thread diameters. What we’ve found is that through rough grinding we take some of the tension out of the shafts, especially the longer, thinner ones. After rough grinding, the shafts leave our department and get threaded on the lathes and possibly milled to cut keyways. Then they come back and we do our finish OD grinding. At that time the tight tolerance ODs are going to have much less grinding stock. We will have somewhere between 0.005 to 0.010" [0.13–0.25-mm] stock on the bearing diameters for finish grind.
"Whenever we steer away from our standard spindle shaft, a 55" [1400-mm] long stainless steel shaft, 3" [76-mm] in diameter and we’re basically running the whole thing with multiple diameters, we don’t need to change wheels. Everything is the same, the same abrasives, same diamond, same coolant, so we never have to do much tear down," Schubert said.
AME’s Studer S40 features two OD wheels, two ID wheels, and a Y axis that allows installing an ID spindle in a vertical orientation so that you can grind slots and keyways. It also has a C axis for out-of-round grinding, thread grinding, and spline grinding as well. "We have one large angle head and then we have what we call our secondary wheel, which is a smaller, narrower wheel. What we found is that it works incredibly well on chamfers, radii, getting into tight spots and reverse grinding. We’re really glad that we made the decision to have that configuration," Schubert said. "This configuration really has paid off. I can buy inexpensive conventional aluminum oxide wheels, because we know we’re going to do a large amount of that kind of work. Our dressers will last at least the lifetime of two wheels."
Occasionally some of the spindle shafts will come in with diameters that include a band of ceramic that the customer uses as a seal. In the past, AME did all the normal OD grinding and then sent the part out for someone else to grind the ceramic with perhaps CBN wheels. Now, however, with the Studer the operator roughs the shaft down with the big wheel, then brings the smaller wheel over, and he can hold a very fine microfinish on the ceramic with the same exact tooling that’s on there to grind regular steel, eliminating the need to farm parts out.
Schubert said that since they acquired the Studers, for the first time they have a machine that grinds more accurately than they can check. Measuring tight-tolerance OD grinding accurately is a costly process. To address this issue, they acquired master setting disks of virtually every bearing diameter size that they do.
AME grinds IDs on each shaft as well. "We OD grind the tapered tools that go inside the spindles," Schubert said. "We have acquired virtually every size CAT taper to grind CAT tools, plus we do HSK tools. We have air gaging made by STOTZ, so we have a proven process on the diameters, on the bores, and diameters of the tools that are going in our bores. Some of these tolerances are in the millionths. The tighter tolerances are on the HSK tools, and some of the smaller ones are ±60 millionths in diameter. The industry calls these ‘simultaneous fits’. Right now on my floor I have a couple of shafts with HSK 125 tapered tools. These shafts have a 14" [356-mm] diameter and weigh 400 lb [181 kg]. The HSK in this case is going to be about 4" [102-mm] diameter on the taper. ME
For more information from United Grinding Technologies, phone 937-847-1229, or go to www.grinding.com; Advanced Machine & Engineering, phone 815-962-6076, or go to
www.ame.com; Integrated Machinery Systems, phone630-250-8305, or go to www.imscnc.com
Becomes Shop’s Product
One company’s machining challenge became an opportunity while it was trying to find ways to improve workholding for machining radio-controlled helicopter engine parts. The end result was a new state-of-the-art workholding product that the company now markets.
In 2007, Kevin Liboon, owner of K2 CNC, met Jerome Mezzasalma, a mechanical engineer who also set up manufacturing facilities, through a shared interest in flying the high-end radio-controlled helicopters that feature KME engines. The two of them then collaborated to significantly enhance the already high-performance characteristics of the heli engine.
Many of the components used in KME engines must be machined to extremely tight tolerances for the engines to work at a high-performance level. They found that the answer to holding tight tolerances while machining KME engine parts lay in perfecting the production of the unique tombstone they designed for use in their manufacturing process. "We needed to be precise, repeatedly. We are making machines that make the machines," said Mezzasalma.
The company designed a patent-pending atypical workholding device; a tombstone with a hollow core, an integrated five-axis rotary indexer, and the ability to add up to eight indexers. The two-sided column design allows for multiple five-axis machining work in one setup. The indexer allows the workpiece to rotate so the user can perform several operations on one part, allowing the operator to cut up to five sides in one operation, cut four parts simultaneously, or cut four different parts in four different operations.
The tombstones allowed KME Engines to quadruple the output on manufacturing the heli engine parts by reducing four operations to just one. It also provided much faster rapids, tool changes were three times as fast, and the machining process was more accurate.
The tombstones worked so well, they realized there was great potential in their design for all types of manufacturers. As a result, in 2009, KME CNC (Orange, CA) was born with Liboon and Mezzasalma as partners and co-owners. KMC CNC offers custom-designed dynamic workholding and fixtures based on their five-axis tombstone design.
In four short years, KME CNC has grown to 14 employees with an 18,000 ft2 (1672-m2) manufacturing facility. KME has 28 independent sales representatives across the US and is focused on expanding their OEM business. KME CNC’s customers span a wide range of industries.
KME CNC’s indexers, tombstones, and trunnions can be utilized for both vertical and horizontal machining applications. The indexers can be mounted directly to a vertical mill or a KME five-axis tombstone in a horizontal machining center. They provide faster, more efficient machining and can hold tight tolerances. The KME drive system provides precision accuracy, repeatability, and rigidity.
After talking to a number of manufacturers with KIWA HMCs and to Selway Machine, west coast dealer for Methods Machine Tools Inc. (Sudbury, MA), a leading supplier of machine tool technology and automation, they decided to purchase a KIWA KH-45 horizontal machining center.
"I have to say the KIWA excels when it comes to torque, repeatability and accuracy. Plus, the large 500-mm work envelope allows us more flexibility," said Mezzasalma. The KH-45 features expandable tool and pallet technology that allows users to expand as business grows. For example, customers can start with a two-pallet machine with 120 tools and expand to a six or eight-pallet machine with 220 tools.
"We try to use the KIWA for any operations that have more than two setups because the KIWA KH-45 allows us to produce parts faster and more accurately," said Liboon. "You can’t even compare the performance of the KIWA to the previous machining center we had. It’s like night and day. Plus, the tool changes are smooth and having the control panel on the left side of the machine makes it easier on the operator. On other machines you need to turn your head away to view the part."
KME CNC is using their KIWA to make all their tombstone parts, including the faceplates, gears, transition plates, and motor covers. "We are confident with the KIWA. Parts repeatedly mike out perfect—from the start of the day right through to the end," said Liboon. ME
For more information from Methods Machines Tools Inc., go to www.methodsmachine.com, or phone 978-443-5388.
Testing Goes Lean and Green
RedViking (Plymouth, MI) made its mark in automotive power transmission test stands beginning in 1981 as Superior Controls. Spun off in 2010, RedViking designs and builds powertrain test equipment, metrology, and production solutions for government and commercial OEMs. For a recent defense department customer, RedViking was challenged to replace an existing bank of 20 individual test stands, ranging from 20 to 50 years old, used for dynamic testing of performance factors for Apache, Blackhawk helicopter powertrain transmissions.
The legacy test stands were anything but lean and green. They required an increasing amount of maintenance, consumed excessive power, and wasted floor space. Spare parts weren’t readily available, unique training was required to operate each stand, and they didn’t produce the desired level of data for analysis.
When a unit test was required, the test article would be built up and dressed within the envelope of the test stand, fully connected, tested, disconnected, and then removed from the workcell. This procedure produced extremely long downtime on the customer’s equipment utilization with various corresponding challenges to logistics.
New testing system requirements included better compilation of test data, automatic closed loop operation of the machinery, true speed and torque measurement with a local test executive as the main operator interface to the test machine and, finally, a standardized control platform to allow easier operator cross-training on the equipment.
The customer set the goal high: three to four tests per working shift versus the current one test per shift being achieved with their multiple machines. RedViking performed its onsite assessment and subsequent situation analysis, and then devised a solution that utilized common components and an entirely new material handling strategy. A series of five flexible test stand designs was determined to be sufficient to replace all existing machines.
To improve efficiency in utilization of the test stands, a series of workpiece carriages was designed, allowing the Units Under Test (UUT) to be mounted and staged outside the envelope of the test stand and then brought into the work cell for faster connection, test, disconnect, and exit. RedViking terms these devices Transportable Test Fixtures (TTFs), which automate shaft connections, clamping, and positioning, as well as providing 360° access to the UUT. This design provides significantly greater efficiency as well as a safe and ergonomic operator environment, reducing hours of test setup time to minutes.
RedViking Controls and Software Manager Jason Stefanski and his team devised an entirely new, modular software system and common human machine interface (HMI) platform for all five test stands, with a common user interface and plug-in architecture, comprising common function blocks, I/O coding and CAT 4 safety functions. This design approach allows the software to be easily configured to accommodate the various transmission models being tested.
Once the test article in the TTF is automatically positioned and attached, RFID tags on the TTF identify both the article and its test profile configuration and communicate them to the Test Executive. All test profiles are generated and stored offline, with modifications made by the customer’s engineering staff outside of the test cells. Test profiles are then linked to the UUT type and model data for further system integrity.
The main software feature of the test machines is the ability to execute a fully automated, repeatable, and traceable test. To provide this functionality, RedViking has developed a Test Sequence Set (TSS) Editor, allowing all parameters to be set by the customer, downloaded to a Test Executive from a localized laptop, thus eliminating the need to modify validated machine code. The TSS editor provides the customer with adaptability to easily modify future or existing test profiles.
After a review of the potential suppliers for the power components and controls on the new test stands, Siemens Industry Inc.’s Drive Technologies Division (Norcross, GA) was chosen to provide the motors and AC flux vector drives packages with regenerative braking for increased energy efficiency. RedViking worked closely with Siemens to devise an AC system, utilizing the regenerative technology found in Sinamics drives with 480V and 690V standards and investigated performance specifics of regen drives used with 3000 hp (2238-kW) motors.
The use of Siemens regenerative braking technology allows a system to recover power, minus the parasitic losses. Conventional dynamic load testing requires loading to occur via an eddy current or fluid brake system, which requires additional energy, maintenance, and up front capital investment. In more innovative industrial environments, according to Siemens, Sinamics regenerative drive technology can enable energy savings of 40% or more.
With a common DC bus architecture, this allows for only one AC to DC conversion in the motoring direction and the regenerative braking power goes straight to another inverter, which is motoring via the common DC bus link. This method eliminates two conversion points where energy would be lost, increasing overall efficiency. In addition, the common bus solution paired with the active front end (AFE) has the ability for power factor correction, which will further increase the overall savings of a common bus system. All AFE drives allow for unity power factor and low total harmonic distortion (THD) that meets IEEE 519 harmonic standards. This means these drive systems can improve the present power factor displacement in a customer’s facility.
RedViking estimates that a test on the main transmission flexible test system, while running at full capacity, will cost approximately $400 less per hour to operate than current comparable systems. With improvements over the conventional non-regen testing process, the RedViking main transmission test system could generate approximately $500,000 in annual power savings.
For this project, Siemens supplied its high-performance asynchronous Simotics 1PL6 and 1RN4 motors, the largest being 3000 hp (2237-kW), to power the various mechanisms on the RedViking test stands. When in operation, these motors simulate the power generated by the helicopter’s jet engines, in addition to simulating the loading of the main rotor and tail output blades. This allows RedViking to test the helicopter transmission components to the full speed and torque requirements as specified by the military with very precise closed-loop control.
On the Tail and Intermediate Gearbox Flexible Test Module, it was determined that the use of two more Siemens Simotics motors was less expensive and more efficient than the previous test stand’s gearbox design. This solution involves multiple motor connections to an output variable frequency drive (VFD) with auxiliary connections, thereby eliminating the need for additional VFDs.
"We knew we were building these test stands to validate the performance of military helicopters that see wartime action," said Joshua Gibbs, RedViking manufacturing coordinator. "We take it very personally at RedViking to ensure these systems protect man and machine alike, as well as provide the ultimate in test validation." RedViking currently performs both DO and DX contracts for the military and its subcontractors. ME
For more information from Siemens Industry Inc., go to www.usa.siemens.com/motioncontrol, or phone 800-879-8079.
This article was first published in the February 2013 edition of Manufacturing Engineering magazine. Click here for PDF.