Derek Korn joined Modern Machine Shop in 2004, but has been writing about manufacturing since 1997. His mechanical engineering degree from the University of Cincinnati’s College of Applied Science provides a solid foundation for understanding and explaining how innovative shops apply advanced machining technologies. As you might gather from this photo, he’s the car guy of the MMS bunch. But his ’55 Chevy isn’t as nice as the hotrod he’s standing next to. In fact, his car needs a right-front fender spear if you know anybody willing to part with one.
Until recently, U.S. shops interested in seeing large WFL turn-mills in action (the company refers to them as “millturns”) essentially had two options. The first would be to have a WFL rep set up a visit with an existing user here in the States to see how that shop is using the technology. The second was to fly to Austria to see machines at the company’s global headquarters in Linz. (I’ve been there, and in my mind that isn’t all that bad an option...)
Nonetheless, now there’s a third, perhaps more convenient, option for shops in the States. The new Autania “Tec Center” in Wixom, Michigan, has two WFL machines that customers can learn more about and arrange to have demo parts produced. (Autania AG is a holding company with several European machine tool OEM member companies having diverse technology offerings. WFL is one of these companies, and moved its U.S. offices to this new tech center in Wixom from its previous location in nearby Novi.)
One machine at the Tec Center is the M35 Millturn model shown above. This is the smallest machine WFL offers (although this company’s definition of a “small machine” might differ from others.) The M35 has a milling head offering -110 to +110 degrees of B-axis rotation and spindle power of 20 kW. Nominal distance between centers is 2,000 mm and maximum turning diameter between centers is 520 mm.
The other machine at the Tec Center is a larger M120 Millturn, and you can get a sense of its size from the shot above. The M120 has a milling head offering -110 to +90 degrees of B-axis rotation and spindle power of 30 kW. Nominal distance between centers for this model can range from 2,000 to 8,000 mm (even longer upon request). However, this isn’t WFL’s largest machine. That would be the M200 model, offering nominal distance between centers ranging from 5,000 to 14,000 mm (even longer upon request), and maximum turning diameter between centers of 2,000 mm.
In addition, WFL offers a range of technologies to tailor a machine to a user’s specific needs. For example, in-process part probing is commonly used to ensure accurate machining of very complex parts. This video shows an example of it being applied to large diesel engine camshaft sections.
The tech center includes equipment from other Autania member companies: Elb-Schliff and Aba Grinding Technologies (which now operate under one umbrella: Autania Grinding Technologies) and Profiroll. The ELB Smartline Kombi N10 840D at the Tec Center is a surface and profile grinding machine with a travelling-table design that can perform basic reciprocation surface grinding as well as slot, profile, speed-stroke and creep-feed grinding. This model offers grinding length, width and height of 39, 15 and 27 inches, respectively. Its spindle drive is rated at 64 hp.
(Speaking of Elb, the company says it has developed the world’s first hybrid grinder with a laser metal deposition system, a version of the company’s “millGrind” machine line. Additive Manufacturing reports on this technology here.)
Profiroll is a manufacturer of thread-, spline- and ring-rolling machines. The company’s Rollex HP spline rolling machine shown above at the Tec Center combines CNC control with symmetric circular dies to create splines onto various types of shafts. This process correlates to a rolling rack of infinite length. The machine can also coldform profiles and threads, as well as perform finishing rolling with its profile rolling process.
Dr. Helmut Rothenberger, owner of Autania AG, says the value of all machines at the center is $5 million. Soon, additional equipment will be installed to provide die-regrinding services for Profiroll customers. He notes that the investment in this facility represents his member companies’ commitment to the U.S. market, a market he feels will experience further growth in the coming years.
Chris Guidotti, vice president of operations for East Branch Engineering, uses a pallet jack to maneuver the 2OP CNC milling machine from Southwestern Industries into position near one of the shop’s Brother VMCs.
East Branch Engineering often uses live-tool turning centers to complete complex parts in one setup. However, it also leverages a flexible and reconfigurable “mini-cell” strategy with a pair of portable CNC milling machines that can be easily transported next to any of the shop’s conventional VMCs or turning centers and then perform secondary operations, run dedicated, small-batch jobs or machine prototypes. That way, a single operator can tend two machines rather than standing idly by, waiting on just one machine to complete its operations, and the shop essentially gains “free” machining time by overlapping operations. Learn more.
Bar-fed rotary transfer machines combine multiple cutting stations around the periphery of a round, indexing table. (These tables are commonly oriented horizontally, but “trunnion-style” versions in which the table is oriented vertically are also available.) Fixured or collet-held workpiece blanks arranged around the table are indexed from one machining station to the next until all operations are completed. (Some stations are used to invert the workpiece to enable back-side machining at subsequent stations.) A finished part(s) is ejected with every index of the table.
The Hydromat open house event I attended last month at its U.S. headquarters in St. Louis, Missouri, was timely because I was able to see a few rotary transfer machines in build that demonstrate the degree to which they can be tailored to specific high-volume applications. Although what’s shown below is a random sampling, it represents varying levels of rotary transfer sophistication engineered to meet a user’s particular production needs. For example (in the order of basic to complex):
This Epic R/T 25-12 collet-style machine with a single bar feeder and no vertical machining stations represents a basic rotary transfer system. It’s similar to original Hydromat designs that were hydraulically driven, but it’s CNC-controlled. As for the model number identification, “25” indicates the diameter of the barstock material it is designed to accommodate (25 mm) and “12” is the number of available machining stations.
This Epic R/T 32/45-16 machine (16 stations can be set up for 32- or 45-mm maximum barstock diameters) has two opposing bar feeders delivering stock into stations 180-degrees from each other. The operations performed are the same around each side, and two finished parts are dropped with each index. (It’s basically doing the work of two machines simultaneously.) So around each side, stock is fed into the first station, machining is performed on the next three, the part is inverted on the following one, back-side machining is performed on the next two, and the completed part is ejected on the last. Note that this setup also has four vertical machining spindles.
This Epic R/T 25-12 machine also has two bar feeders. However, instead of opposing each other as in the previous example, they feed small-diameter barstock into adjoining stations. Plus, each has been modified to feed two bars apiece into custom workholding collets designed to hold two parts (not just one as you might expect). As a result, four parts are dropped complete with each 3.4-second table index, helping the customer to meet its very-high-production volume goal.
This Epic HS 16 indexing chuck shows the extent to which ancillary equipment can be added to offer a complete parts manufacturing solution, including robotic part handling, part gaging and part cleaning.
At the open house, Hydromat also offered a sneak peek at its Epic Gen II rotary transfer machine platform, which will be officially introduced at IMTS 2016. This next-generation version of the company’s flagship rotary transfer machine line (shown below) includes a number of advancements related to servomotor, process feedback, programming software, reporting software and other technologies.
Here are two examples of complex custom tool concepts that Quinn Saw can print and provide to customers so they can more easily comprehend the overall design concept compared to basic illustrations.
Say you need a custom cutting tool that’s likely to cost you a few grand. Would you rather the cutting tool manufacturer you’re considering provide you with a CAD model or printout of the design or, better yet, a 3D-printed prototype of it?
Started in 1903, Quinn Saw is a single-family-owned business that’s now into its fifth generation. Bill and Joe Zickel are the current owner-operators (4th generation). The company’s core business has always been reconditioning saw blades and manufacturing new ones, but it has since branched out into custom tooling with Troy as the lead designer.
Troy actually worked for Hydromat from 1997 to 2007 as a tooling engineer, engaging with Quinn Saw (Hydromat’s primary blade supplier for its rotary transfer machines) on many projects to improve the barstock sawing process using HSS and carbide-tipped blades. After joining Quinn Saw in 2007, Troy started developing custom tools, such as the printed prototypes shown above, for unique customer applications.
So why the 3D printer for prototypes? Troy says one reason is that his tooling designs often have intricate features and details that are difficult for many people to fully understand and appreciate just looking at paper illustrations. Plus, the people making the purchasing decisions often are not as familiar with the project as their engineering staff, so the printed models enable the decision makers to have something really close to the actual tool in hand, making it easier to comprehend the overall concept.
But another reason had to do with preventing possible interferences. He points to a tool that took 8 weeks to manufacture. Although the customer was happy with how it looked, the tool ultimately didn’t fit into the required space due to an interference with another device in the tight machine environment. This required rushing the tool back and forth between parties for revisions, which was expensive, but Troy notes the biggest impact was the unexpected delay and black eye for providing a tool that was not functional upon receiving it. After resolving the issues and providing a successful tool, Quinn Saw management met to determine how to prevent this from happening again. The idea of using a 3D printer for prototypes was brought up, so Dan Zickel (of the company’s fifth generation) was tasked with sorting through all of the available 3D printer types and options to determine what model was most suitable and cost effective for its needs. After significant reviews of the vast array of machine types, sizes and cost, Dan narrowed it down to the Formlabs Form 1+, which it purchased this past February. This printer offered a suitable printing envelope with a very reasonable cost as well as high printing definition.
Quinn Saw chose this Formlabs Form 1+ SLA 3D printer because it offered a suitable printing envelope, a very reasonable cost and high printing definition.
The machine was purchased just before this year’s Precision Machining Technology Show (PMTS) in Columbus, Ohio. This enabled Troy to print and offer models of concepts to show attendees rather than just pictures. Plus, having high-cost actual tooling on a show display table typically isn’t practical or cost effective unless you have a guaranteed avenue in which to sell it afterwards. The 3D printer is also used to scale up small tool features (see the photo below) that would normally require viewing through a magnifying or inspection device, which sometimes isn’t practical at a trade show or in front of a customer.
The company’s 3D printer is also used to scale up small tool features that would otherwise require a magnifying or inspection device to see.
The company sees value in using its 3D printer in other ways, too. For example, Troy says coolant delivery has been a problem for one of Quinn Saw’s grinding machines that has an articulating head. The company is considering printing a new guard with internal coolant ports. Although this design would be costly and impractical to produce via conventional machining, the 3D printer could produce the complex part at little expense. Then after experimenting with the printed guard on the grinding machine, it’d be easy to tweak the design if necessary and simply print another to try.
Troy cautions that while 3D printing technology is helpful, it’s not perfect. Quinn Saw’s 3D printer uses support material during printing that basically snaps off after the part is printed, but leaves small imperfections where it was attached. Those must be removed by filing and or sanding. Plus, there is a fair amount of physical cleanup on printed components to make them all fit precisely and look more presentable—parts don’t just emerge from the resin batch complete and perfect. But in his experience, while the technology is still in its infancy, it is evolving rapidly and so are the machines that do the printing.
For this demonstration, the robot performed both workpiece pallet changeout and simulated polishing operations of machined parts.
I’ve been aware of the Run MyRobot capability available with Siemens Sinumerik controls for a little while, but I believe the cell below that was in Handtmann’s EMO Milan booth represents the first time I’ve seen a demonstration of the concept using an actual machine tool.
The idea is to provide intuitive robot programming capability at a machine’s CNC via the Sinumerik Operate GUI. In the case of this cell, the execution of the movements of the six-axis Kuka KR 600 Fortec robot (with 600-kg load capacity), provision of robot safety functions and other robot-specific functions are performed by the Kuka KR C4 robot control. However, that control is connected to the Handtmann five-axis HBZ Trunnion 80 machine’s Sinumerik 840D sl CNC. Therefore, the machine tool operations and robot program can be tracked and controlled on one screen via parallel channels.
The machine tool operations and robot program can be tracked and controlled on one CNC screen via parallel channels (the robot channel is shown here).
For this demonstration, the robot performed both workpiece pallet changeout (using Schunk clamping systems) and simulated polishing operations of machined parts. Of course, the robot can be used to perform a range of secondary operations, including drilling, brushing and deburring, depending on a manufacturer’s needs.
Check out this video that shows the cell at the show.