Cold presses using Delta Motion controllers help ensure consistently stronger, more accurate fittings for military vessels.
With roots in the 1960s, W&O Supply has a lengthy pedigree in serving the maritime industry, doing everything from repairing valves to supplying pipe to retrofitting military vessels. The company has 18 branches across the U.S., Europe, and Asia, all dedicated to supporting marine construction, repair, and servicing. Naturally, servicing big ships often requires big fittings — sometimes massive fittings ready to move oil, steam, seawater, or anything else a ship might need.
Ships often requires big fittings — sometimes massive fittings ready to move oil, steam, seawater, or anything else a ship might need.
Cold presses tend to produce stronger, more accurate fittings with greater consistency than hot presses (which can make the metal more brittle). There are obvious environmental benefits to using less energy by producing less heat. Cold press fittings shape pieces by bending them over a mandrel or through a closed die, which attaches to the central press’ ram. However, the military and shipbuilders have stringent specifications to ensure that part materials are in the proper places to reduce stress. A conventional cold-formed fitting might have a pressure rating of 50 to 100 psi. For military and similar maritime applications, though, fittings might need pressure tolerances from 200 up to 6,000 psi. Moreover, their diameter could be anything from 1/4 to 32 in.
According to William Abbott, director of quality for W&O Supply, the U.S. Navy identified “a significant weakness in the supply chain” for such parts starting around 2017. There weren’t enough suppliers in the world making fittings in those size and tolerance ranges. W&O Supply wanted to address the market need for such fittings (through a new subsidiary called Seamless Marine Fittings) and to do so, it needed a very large, highly accurate press. Such presses are not off-the-shelf purchases; each one must be custom-designed and manufactured.
W&O started (relatively) small. As Abbott described it, the first project was “only” a 500-ton press able to handle fittings up to 10 in. The design targeted high-strength materials and difficult-to-manufacture items, and it came off so well that W&O significantly scaled up its next iteration. The “full-size” four-post press handles 3,000 tons or six times the pressure of its predecessor. The total force contributed by all cylinders, each of which provides up to 1.2 kilotons of energy force, is 6,000 tons. Abbott noted that it was “specially built to support the construction of military vessels — submarines, carriers, destroyers — although there are some fittings in the commercial world this product would fulfill nicely.”
The W&O cold press can design varying size fittings for marine vessels.
The search for advanced motion control
William Abbott and W&O Supply have tried a range of motion controllers in their presses over the decades. Too often, though, motion control solutions ran up against what Abbott referred to as “the black box effect.”
“They come out and say, ‘This’ll do everything you want,’ and they spew enough technology talk at you to believe them. But then there are too many limitations. Or you can’t do something because it was never intended to do that, and the features won’t support it,” Abbott said. “Now, there are controllers built with such open architecture that you have almost hardware-level access to fundamental components, inputs, outputs, ADCs, and you can change how they do things. But a lot of systems don’t provide that level of access. They’re just black boxes you can’t see inside of.”
Abbott had seen other companies use controllers from Delta Motion enough to be acquainted with their functions and operation. As W&O planned for its large cold press, Abbott launched discussions with Delta to gauge their confidence level in Delta’s RMC motion controllers’ ability to handle the task. He was justifiably concerned because W&O needed to perform certain operations in certain ways that weren’t generally done on hydraulic presses. Once he got his hands on Delta’s RMCTools software, he realized that its simple interface belied a remarkably versatile functionality that “gave us all the access needed to do pretty much whatever we wanted. It became very clear that the product was exactly what we needed.”
W&O procured a Delta RMC200 motion controller equipped with SSI interface modules, high-resolution analog modules, and two digital channels. The modules were so configurable that Abbott said W&O didn’t have to “worry about buying a special module for a special widget.” Most other controllers he evaluated required special adapters and/or programming, thereby increasing design complexity.
W&O Supply chose the RMC200, which can control up to 50 axes.
“With Delta,” said Abbott, “I can bring in SSI and analog feedback for position and velocity. It quickly became clear that Delta understood that motion is not just one path and that there are all different kinds of motion. That showed a level of understanding I found impressive because not everybody does that.” Delta’s RMC motion controllers don’t just give a position set point, they also provide a continuously updated target position, velocity, and acceleration up to 8,000 times per second or 125 μs.
With input from Delta engineers, Abbott collaborated with his hydraulic designers on fine details, such as the selection of valves. He reasoned that anything modulating velocity or pressure to the demands of this project must respond accurately and repeatedly under such high-pressure conditions. This design process was critical to the final solution. The wrong valve would ultimately doom the entire project, as Abbott had found in other implementations.
All in all, the Delta integration could not have gone better, thanks in part to the quality of Delta’s PROFINET connectivity. Abbott notes that typically, one to two weeks is allocated to get a motion control rack up and running. With Delta and the cold press, the team started on Monday morning after getting electronics brought up. They had the racks communicating by midday and cylinders moving that night. Integration was completed in a single day.
Similarly, the normal time required for tuning the motion axes on an installation would have been a week. With Delta, it was only one more day.
To make a point of the contrast, Abbott called out the motion control solution used on W&O’s smaller 500-ton press, which he referred to as Company S. He said Company S had recently gotten into motion control and claimed it could do everything needed. “It still doesn’t, and it’s been four years,” he said. “It still does not work as well as what we accomplished in two days with Delta — because Company S knows their own standard, but they’re not motion experts.”
Software, support and scaling
W&O Supply valued Delta RMCTools for its user-friendly interface and powerful features, and especially that it was available at no cost. Abbott noted that many years ago, spending $100,000 on hardware might have resulted in user-free software, but “now it’s flipped.” He said that buying a $5,000 controller might still require a $20,000 outlay to let the controller deliver its promised functionality. Delta’s programming software provides the same powerful feature set needed to optimize performance, regardless of which controller was purchased. Whether a company opts for the least or most expensive controller in Delta’s lineup, RMCTools is included at no additional cost.
W&O Supply chose to purchase Delta’s upper-end RMC200, which can control up to 50 axes. This greatly exceeds the application’s current needs of five axes, but Abbott had scalability in mind from the outset. In his 40-year career, he has seen machines grow and change over time. He pointed to cold presses from the 1930s and 1940s and how they were built for strength, robustness, ease of maintenance, and scalability. This is at odds with practices from later decades, such as the 1980s, when automation optimized around a single application, and any sort of major application change often meant replacing the entire system. One factor that drew Abbott to Delta was recognizing that the motion control company’s long history in the market had resulted in that old-school perspective on how to make a system that could withstand half a century of use and evolution.
He also admired Delta’s approach to service — referring to Delta Motion’s emphasis on knowledgeable and responsive technical support. “I once paid six figures for automation from another company, and it took a week to get a guy on the phone who knew how to use it. These companies get so big that they can’t find the right people. When you finally find the right person, guard their contact info because it can be painful to find another one. But that’s never happened with Delta. Every person I’ve talked with knew exactly what to do. That indicates to me a unique caliber of training, understanding of customer needs, and living up to those needs, both with people and product quality. If I had it all to do again,” Abbott added, “I’d pick Delta in a heartbeat. Since commissioning this application, we’ve had zero failures, and we’ve had to make zero adjustments. The motion system has been in continuous operation since inception and continues to deliver unmatched performance.”
Delta Motion
deltamotion.com
Filed Under: Components Oil Coolers, Controls, Motion Controllers
