Magnus Precision (Phelps, NY) is one of the premier contract shops in the Northeast. Housed in a world-class 55,000 ft² (5109 m²) facility, the company is respected among customers and suppliers alike for its meticulousness in producing complex components for the aerospace, medical, optical, and micromachining markets. It embraces a philosophy of applying the latest advances in machining technology to keep the competition in its rear-view mirror.
When Don Miller, director of business development at Magnus Precision, received a call from the Hardinge Group (Elmira, NY) asking if his company would beta test its latest Super-Precision T-42 multitasking turning center, he replied, "Yes, how soon can you deliver it?" Magnus had many years of compatible experience with the machine tool builder’s previous Conquest T-series generation with live tooling, and wanted to assess the impact that the new turning technology would have on the company’s precision-machining work.
At Magnus Precision, in addition to quantifiable time studies, productivity gains are measured in better accuracies and improved surface finishes, less scrap, and reduced part-handling time. "We knew that Don and the skilled workforce at Magnus would provide the thoughtful, practical feedback we needed before releasing the machine to the world market at IMTS 2010," explains Paula Ameigh of Hardinge.
Accordingly, the Hardinge SP T-42 turning center was installed in July 2010. Magnus immediately put it through its paces on two test parts. The first was a 440C stainless valve component for an aerospace customer. Miller felt this was an excellent choice, because the approximately 4" long × 1.5" diam (102 × 38-mm) part required a number of turning, milling, and drilling operations that would test the live tooling option on the machine and the subspindle performance.
Previously, the valve parts were turned on a CNC lathe and then transferred to a VMC for the milling and secondary drilling operations. Once the off-line programming was accomplished using PartMaker and downloaded to the machine’s 0.000010" (0.0003-mm) resolution Fanuc 31i CNC control, the SP T-42 was ready for production. There was one surprise in store for Magnus personnel, however. While familiar with live tooling on other turning centers, Magnus didn’t have experience with the BMT-45 top-plate system on the SP T-42.
"The BMT-45 system was new territory for us," says Miller, "and it’s that aspect of the machine that provided the most surprising results. Most manufacturers aren’t as familiar with BMT tooling or BMT top plates as they are with the more common VDI system. We found that BMT top plates are significantly more rigid, with a heavier-duty interface. With the proper gear ratios in the toolholders, you can achieve unusually high speeds, up to 32,000 rpm. We took an approximate previous cycle time of 40 min down to a total of about 14.5 min—part complete, one machine, one setup. We’ve almost tripled the productivity, and are looking forward to working with those higher rpm on our micro-medical components."
The BMT-45 turret offers 16 live tooling stations with one half-station index between each station. Both the static and live toolholders are designed to adapt modular add-on toolholder blocks for user flexibility and allow fine tool adjustment in the Y-axis plane. Typically, maximum live tooling rpm are in the 5000–6000 range. Live toolholders on the Hardinge BMT turret start at 8000 rpm, and, when high speeds are required, are capable of up to 16,000–32,000 rpm when purchased with ratios of 2:1 or 4:1. They provide run-out within 0.00012" (3 µm).
The second test part, a classified titanium (Ti6Al-4V) aerospace part, featured 0.0003" (0.008-mm) tolerances on several features. "We knew that particular part would relay the precision aspect of the SP T-42 very well. We held the tolerances with no problem, part to part," says Miller.
"Thermal stability is paramount to accuracy, too, and we are skilled at chasing it here at Magnus," says Miller. "The SP T-42 has a detached stand, which houses the coolant pumps, coolant filter, machine power case, and hydraulic system. By design, the detached stand prevents these heat and vibration-generating components to migrate through the machine, resulting in the machine’s ability to achieve higher thermal stability and, thus, part accuracy. Further, the spindle is cooled using an oil jacket and chiller for even better thermal properties."
Finishes are a significant aspect of the overall accuracy and precision requirement, in particular on the company’s optical and medical components. Part finishes of 0.000006" (0.15 µ) Ra are routinely achieved on the SP T-42. Hardinge’s subspindle parts-removal system is designed for handling critical parts with delicate surface finishes. The gripper includes machinable nylon inserts that are gentle on parts. Users can opt for a parts conveyer where components can be off-loaded manually or integrated with a robotic device, permitting untended operation with a barfeed.
During the beta testing phase of the SP T-42, a couple of minor issues surfaced that Magnus relayed to Hardinge. The issues were related to software and implementation of the Fanuc 31i control to the new Hardinge T-series.
"This was the whole idea of beta testing with Magnus," says Jim Langa, vice president, Engineering & Global Sourcing at Hardinge, "to learn what we needed to tweak. We resolved those items quickly by working with our software and applications engineers and directly with the Fanuc software engineers."
"As for us," says Miller, "with the positive results we’ve achieved in such a short time, we are looking forward to putting more of our complex parts on the machine. Continuous improvement can sound like a cliché, a buzzword, but at Magnus, we are very serious about it to not only stay in business, but to thrive in a challenging economy. We keep figuring out better ways of doing things for our customers. They bank on our philosophy. The SP T-42 plays right into those goals." ME
For more information on Hardinge, go to www.Hardinge.com, or phone 607-734-2281.
Saw Blade Wear Woes
Having a diversified workforce and a wide range of service offerings has proven to be an effective business strategy for Best Equipment & Welding (Indianapolis, IN). The company actively pursues multiple lines of business including loading dock equipment, a full-service fabrication shop, and a wide range of industrial installation services.
While diversity has been good for business, it has been murder on bandsaw blades, according to Best Welding & Equipment’s Maintenance Manager, Larry Frank. "Because of all the different materials and shapes we cut, we were having a serious problem with how long the band blade lasted on our three Hyd-Mech vertical hydraulic bandsaws. We reached a point where we were barely getting 100 cuts out of the blades provided by a respected manufacturer."
Blade life woes were costing the company hundreds of dollars in premature replacement costs and annoying downtime every time team members had to stop what they were doing and change-out a blade. Frank attributed the steady decline in blade life to several different factors: inconsistent use by Best Equipment personnel, the need to cut a wide variety of materials and shapes, and an increasing reliance on bundle-cutting to improve manufacturing efficiency.
There are two different teams of workers who use the bandsaws at Best Equipment & Welding. One team of nine works in the company’s full-service fabrication shop. Another team of eight staff road crews, who install loading-dock equipment, erect industrial structures such as rails, stairways, and doors, and perform safety-critical jobs such as the installation of structural columns.
The bandsaw usage patterns of these two groups are very different. The shop team, for example, uses the bandsaws throughout the day for cutting carbon steel, stainless, and aluminum to fill bills of material for specific manufacturing jobs. They could be cutting any kind of shape, including flats, tube, angles, and others. Materials are frequently bundled for efficient cutting.
Frank explains that since the shop guys are always around, it’s easy to give them consistent training and keep them informed about how to set up the proper feed rates, pressures, and saw speeds for various materials and cutting situations. The shop guys are aware of bandsaw best practices and adhere to them, because they do not want to be changing a blade when they have a project they are trying to move along.
The road crews are usually on the job early in the morning or late in the day, cutting small numbers of pieces for their next job away from the shop. They are usually in a hurry, because they need to be on the site as soon as possible, or they are tired after a long day’s work. When a crew member wants to cut a few pieces, he or she does not always pay attention to the blade speed or to the correct feed force. They just want to cut their stock and get on with what must be done next.
Of course, inconsistent use was far from the only thing contributing to dwindling saw band life. Ideally, one should select saw blades with the specific material and shape in mind. This is rarely possible at Best Equipment & Welding. On any given day, there are numerous jobs going through the shop with wide-ranging material requirements. "We are cutting anything from 1/8" [3.175-mm] wall tubing to 4 × 4" [102 × 102-mm] angle, flat stock, round tubing, aluminum, carbon steel, and stainless. It all varies according to the job. We generally use the same blade for everything we cut," Frank says.
One exception is stainless. The company sets aside a blade for cutting stainless. This helps the blade wear better, but the primary purpose of using a separate blade is to keep the stainless from being contaminated by flecks of carbon steel that will ultimately rust and make the stainless look inferior.
Cutting shapes is another situation that causes blades to wear prematurely. The initial impact of a blade on the surface of a material is the one that does the most damage to the saw blade. Shapes—angles, tubes, and the like—present multiple surfaces to the blade to multiply the number of impacts during a cut.
Bundles are even more of a problem, because they present not just a few, but dozens of impact surfaces during a single pass, dramatically increasing the likelihood that some of the saw blade’s teeth will be stripped. For example, Best Equipment & Welding will cut bundles of 50 pieces of 2" (50.8-mm) flat stock, welded on the edges to keep the pieces from separating during the cut. This is great for production, but puts tremendous stress on the blade.
Best Equipment & Welding took their blade wear problem to five different manufacturers before the L.S. Starrett Co. (Athol, MA) provided the most effective solution with its Versatix blade. Versatix is a bimetal product designed to resist impact punishment delivered in shops that primarily cut shapes and bundles. It’s hard enough for continuous use with solids and heavy-wall tubing, and can even withstand the wear resulting from the occasional cutting of high alloy steels.
Starrett used Finite Element Analysis (FEA) to design the tooth geometry to spread impact forces over a broader area, thus dramatically reducing the incidence of tooth-tip fracturing. The company also uses a diffusion-bonding process that bonds the bimetals at the molecular level, making teeth 30% more resistant to stripping than electron-beam-welded bimetals.
Late in 2009, a Starrett representative visited the shop, installed three Versatix blades, and made sure the saws were set up and adjusted properly. He left three other blades behind as replacements. He also left a control chart that Frank used to observe blade-usage patterns and replacement intervals. For the first six blades, Best Equipment & Welding averaged approximately 400 cuts per blade without changing any fluids or usage patterns.
Ironically, the Starrett Versatix blades cost a little less than the previous blade, even though they are lasting more than three times longer. Now the company uses 15 blades a year compared to 45 or 50. That amounts to an annual savings of about $1400 in the cost of blades alone, and it eliminates nearly 17 hr of labor for changing-out worn blades (frequently at the worst possible time.)
Larry also says that, in addition to technology, there is a little psychology behind the company’s improved bandsaw-blade wear results. "I’ve noticed that since we have installed these ‘special’ blades our teams have more respect for them. They take better care of them. I’m sure that also has something to do with the results we are getting." ME
For more information on the L.S. Starrett Co., go to
www.starrett.com, or phone 978-249-3551.
Tooling Brings Machining
Precision Cycling Parts Inhouse
Freedom and independence are hallmarks of cycling. While these traits are found in every cyclist from Lance Armstrong to the weekend rider, no manufacturer for the wide-reaching sport embodies that spirit more than Cane Creek Cycling Components (Fletcher, NC).
Founded in 1991, Cane Creek is one of the world’s largest producers of high-end bicycle accessories for both OEMs and aftermarket buyers. The company is perhaps most well-known for the invention of the threadless headset, a novel design of the rotatable interface between the bicycle fork and bicycle frame. Cane Creek products have been used on the bikes of two of the last three Tour de France winners.
Cane Creek prides itself on developing and providing high quality, innovative solutions that enhance the cycling experience. Central to this mission is an organization-wide commitment to continuous improvement. Early in 2008, the company identified an opportunity to enhance quality and efficiencies by bringing some of its key manufacturing processes in house.
"Whenever we ordered parts from our subcontractor, the minimum quantities were so great that we were left with months of inventory," says Josh Coaplen, director of R&D. "We also had to certify all materials used in the manufacturing process. Trying to do that with an outside source was both costly and difficult."
In mid-2008, Cane Creek purchased a Quick Turn Nexus 200-II MS from Mazak Corp. (Florence, KY). Designed for done-in-one performance, the multitasking QTN 200-II MS offered high torque, high speed turning performance that was well-suited for Cane Creek’s operations.
To tool the machine, the Mazak salesman recommended Greg Ward from JIT Manufacturing, the only Sandvik Coromant Yellow Coat Distributor in the area. Because Cane Creek was new to CNC machining and the associated tooling, Ward educated the company on tooling capabilities and limitations. He also became familiar with the company’s extensive line of complex parts, which require a variety of small grooves, external and internal profiles, and holes.
"Greg identified process-appropriate tooling that allowed enough flexibility for our diverse parts range and prototyping needs," says Coaplen. "Then he provided us with a tooling package containing a minimal set of tools that, with some tweaking over time, has proven to be a perfect fit for our operations."
After starting in-house production in September 2008, Cane Creek saw immediate results. The manufacturer lowered costs of machined parts by 12%, with production run quantities of less than half of the minimums for outsourced runs. Cane Creek also reduced lead times on its premium line of headsets from six weeks to four. As a result of these improvements, carrying costs also fell dramatically, and cash flow improved.
"The flexibility to complete shorter runs of a variety of assemblies and components allows us to respond quickly to large changes in our industry," says Coaplen. "This puts us in a very competitive position with little to no obsolete inventory."
"Having our own machine helps us to get parts to market faster and cheaper, while also allowing more opportunity for design changes," says Coaplen. "This is bolstered by our adaptable Sandvik Coromant tooling."
This flexibility has shown itself best with Cane Creek’s improved prototyping capabilities. The manufacturer has launched four new product lines in the last two years, with time to market reduced by nearly half. "The QTN 200-II MS is equipped with the Matrix CNC control, which uses Mazak’s conversational Mazatrol language," says Coaplen. "This makes it easy for us to program a part and try something out very quickly. It’s through the experience on this machine that we were able to figure out how to make our new AngleSet product in a cost-effective way."
Another new headset that would not have been possible without Cane Creek’s ability to prototype is the AER. Notable for being the world’s lightest headset, the AER was meticulously machined from 7075-T6 aluminum.
"Both the AER and AngleSet headsets required so much prototyping that our management would not have pulled the trigger on the project if we had to do it outside," says Coaplen.
The cutting-tool manufacturer also assisted Cane Creek in the manufacture of its special edition World Bicycle Relief 110 Reserve headset. World Bicycle Relief is a Chicago-based non-profit that designs, builds, and provides bicycles to people in need in rural sub-Saharan Africa and China.
"This was a limited run project of 200 pieces that required the cutting of high-grade LDX 2101 stainless," says Chuck Scarbrough, Cane Creek’s Sandvik Coromant sales representative. "We helped them understand how to machine this material to their exacting specifications."
The special edition Reserve headset helped Cane Creek raise $26,130 for the organization, which was enough to buy 200 bicycles for people in need.
"Whether we’re developing a new prototype, working with new material, or trying to figure out how to machine more efficiently, Sandvik Coromant is always there to help us out," says Coaplen.
In one situation, Cane Creek experienced increased downtime when a project required the use of three different size CoroDrill 880. "Using all three sizes meant we endured a lot of tooling changes, which can get complicated when using coolant-through tools," says Coaplen. "So we asked Chuck if there was anything we could do to maximize efficiency."
Scarbrough recommended Sandvik Coromant’s Coromant Capto modular tooling system, which is ideal when quick tooling changes are required. Since Coromant Capto integrates easily into multitasking machines, implementation of the new system went quickly. ME
For more information on Sandvik Coromant Co., go to www.sandvik.coromant.com, or phone 201-794-5000; on Mazak Corp., go to www.mazakusa.com,
This article was first published in the January 2011 edition of Manufacturing Engineering magazine. Click here for PDF.