Designing for metal additive manufacturing – Aerospace Manufacturing and Design

Optisys systems-engineering approach consolidates antenna parts from 100 down to 1.

Edited by Robert SchoenbergerAircraft antenna withreflector(bowl shape), antenna feed (running horizontally through its center), and anortho modetransducer (protruding through the rear). The latter two were optimized by designing them for 3D printing.

Designing antennas for 3D printingrequiresa new way of thinking about structures. The early adopters for 3D printing only made prototypes and tooling and that mindset is still pretty widespread. But we formed our company by identifying a niche market where 3D printing is the production method from the start. Were solving end-use challenges with it, Clinton Cathey, Optisys CEO says.

Cathey and COO Rob Smith formed Optisys in West Jordan, Utah, with colleagues who share a combined 60 years experience that includes radio frequency (RF) design, satellite communications (SATCOM), mechanical engineering, and additive manufacturing (AM).

An industry voidAbove are examples of 3D-printed metal antenna feeds customized by Optisys and produced in a Concept Laser AM machine.

The ability to consolidate parts with AM sparked the idea to form Optisys, Smith explains. We had a high degree of intuition that 3D printing would solve many of the problems we fought in our past experiences with antenna manufacturing.

Traditional manufacturing methods can harm radio frequency (RF) performance. Those problems add time and cost to traditional antenna manufacturing, as there are often 100 or more individual metal components in a conventional design including hollow, rectangular waveguides that channel electromagnetic energy carrying data joined together via brazing, plunge EDM, or multiple bolted joints.

Such assemblies can be large and long with unique shapes, creating internal geometric hazards that can interfere withdataflow.

Every joint, seam, or fastener creates the potential for a discontinuity that can result in RF losses as the signal travels through the antenna, Smith says. Even how tight you make the screws can add a lot ofvariability.

Smith explains that when a hundred or more parts are joined together, You have to inspect each piece independently, then put them all together and hope it translates to better overall RF performance. The tolerances of each part have to be very exact, and by the time you integrate so many pieces together, you can have significant tolerancestackupand be completely off target.

Optisys designed and manufactured this one-piece antenna assembly by optimizing a 100-piece design for additive manufacturing.

High-frequency electromagnetic field simulations are used to analyze and optimize 3D printed antenna designs for maximum RF performance.

By 3D printing, the engineering team took an antenna assembly with 100 parts and consolidated them into one by designing the product for AM. By viewing an antenna assembly as an integrated structure in which all the parts are combined into one, the team reduced lead times from 11 months to 2 months, cut weight by more than 95%, and lowered production costs up to 25%.

We did testing to validate our assumptions, took parts to customers to get their responses, and then tested for answers to their questions, Cathey says.

The team identified that the most convincing value proposition was that the smaller size of their additively manufactured products greatly shortened the overall distance that an RF signal had to travel within the system.

Directional, microwave antennas used for most satellite and line-of-sight communications, aircraft, and unmanned aerial vehicles operate in the 1GHz to100GHzfrequency band. In those industries, lightweight design is highly desirable.

We found a sweet spot for 3D printing where the technology provides many benefits and is also economically advantageous, Cathey notes. With our Ka-bandmonopulsetracking array, we tested RF frequencies to 30GHz; other companies have only reached 15GHz.

The Ka-band array was evaluated for bench and outdoor RF range performance. Similar designs have passed rigorous vibration testing for military ruggedness. Subsequent Optisys designs have reached up to 50GHz in RF capacity.

Designing for metal AMOptisys COO Rob Smith reviews support design for an antenna.

Rather than start from a pre-conceived geometry, Optisys engineers begin with the RF requirements for the finished product.

Because AM promotes parts consolidation, we have the freedom to work toward the goal of optimum RF output rather than derived requirements such as individual part tolerances, Smith explains. Passing inspection is a challenge because the critical geometry is internal and cant be measured directly.

For the next step, the groups RF expert, Mike Hollenbeck, develops a microwave simulation using Ansys HFSS software to model the high-frequency electromagnetic field inside the air cavity of the proposed array.

Smith says, Mike and I go back and forth a bit to identify the air-cavity design that best meets our requirements, then I import that file into SolidWorks to figure out the optimum thickness for the aluminum walls that Ill wrap around that air cavity to create a design that can be printed as a single metal assembly.

Smith uses his experience and intuition to create the ideal design topology, adding just enough extra material to form an integrated unit that will print consistently. He also adds support structures where needed, using Autodesk Within, merging the result using SolidWorks and Magics.

These integrated support structures stabilize the geometry throughout the build, draw the heat away so we dont get stress concentrations in shrinkage locations, and then provide the entire system with support when its in operation, Smith says.

Benefits beyond the buildOptisys CEO Clinton Cathey examines a microwave waveguide single-piece assembly manufactured in the companys Concept Laser machine.

The final design is printed with a Concept Laser metal AM machine that uses the LaserCUSING process, a powder-bed-based laser melting of metals.

Aluminum, the preferred material for a build, stands up better than plastics to environmental stresses from ground level to outer space and has essentially the same properties as a solid piece of the same material.

Cathey is optimistic about Optisys growth. Our competitive advantage is the integration of systems engineering, design, and additive manufacturing customized for this niche application. We havent pushed the RF boundaries as far as they can go yet, so metal 3D printing will continue to be pivotal in getting us there.

Concept Laser Inc., headquartered in Grapevine, Texas, is part of GEs additive manufacturing initiative. Read Optisys metrics demonstrating advantages of 3D metal printing at

Avoiding complexity creep with planning software

Enterprise resource planning systems can help manufacturers organize, analyze, and respond to an ever-growing amount of data.

Modern manufacturing links old-fashioned machining with extensive amounts of digital information and data analysis. The resulting combination bucks some traditional industry notions of how tasks get done. As new technology redefines the industry at a geometric rate, a new barrier has arisen: complexitycreep.

As newer technology layers over pre-existing architecture to improve performance, that pervasive creep can slow down the whole system or leave it too complicated for effective use. More than ever, manufacturers need the right enterprise resource planning (ERP) systems to organize, analyze, and respond to a growing amount of data especially from the Industrial Internet of Things (IIoT), which expects to expand to more than 24 billion devices in the next four years, according to Business Insider. Currently valued at $6.3 trillion, according to TechCrunch, the industrys just finding its feet, and many tried-and-true methods arent applicable anymore.

Complexity can be harmful if its costs outweigh its value, but complexity may also provide greater value, such as where it grows the overall capabilities of an existing program. The problem with complexity arises when a simpler architecture exists. A system that streamlines a job is preferable to one that does it disjointedly, even though both technically meet the need. As technology advances, leanness becomes more important. In aerospace and defense (A&D), the ability to secure lucrative future contracts will hinge heavily on efficiency.

The size and scope of legacy systems or a traditional architecture pose obvious challenges to efficiency in the digital age. One common component that hinders digital improvement is the legacymindset,or the tendency for management to run the business the way it has previously and successfully. The way to combat this stasis is to demonstrate a clear strategy with a reasoned rationale that shows how digital transformation will improve competitiveness and the product or service for years to come.

Outdated systems frequently result in higher associated costs, more waste, longer lead times, and a shorter leash for overtaxed management. ERP systems combat these challenges by increasing profitability and efficiency, leading to an integrated downstream strategy that ultimately results in customer satisfaction through higher-quality services and products. By increasing efficiency and simplicity during sourcing and production, and providing the information needed to make quick decisions, the right ERP system allows operations to run smoothly by increasing automation and dynamically handling day-to-day tasks across anorganization,while remaining compliant with industry and federal regulations.

The most nimble, flexible, and strong ERP solutions support mobile business and prominent social platforms to account for the ways customers and suppliers interact with manufacturers. Cloud-based models allow these systems to provide wide ranges of visibility while eliminating physical information technology (IT) burdens, freeing up an organizations time and energy.

A&D manufacturing is slowly coming to terms with the fact that some of its internal processes are notably outdated, even while they are used to create the most innovative breakthroughs the aviation and space exploration fields have ever seen. The growing demand to make A&D manufacturing more streamlined has left organizations feeling boxed in by their own ERP systems and IT departments.

A cutting-edge ERP system is muscular enough to provide drill-down data to research any question or issue and lean enough to act responsively and efficiently to meet any new threat or rise to any new opportunity. Cloud-based systems present additional benefits due to their scalability and reduced costs. These benefits can help companies move past legacy systems and toward a prosperous future.

About the author: Aaron Continelli is president of Cre8tive Technology and Design, an Epicor Partner (Value Added Reseller) and twice Americas Partner of the Year. He can be reached at 858.457.2786

The right machining center, control, advanced 5-axis CAM software, and conical barrel-style end mills can optimize cutting efficiencies when making complex parts.

Manufacturers could slash 90% off finishing cycle times when machining deep-pocketed workpieces. This can be achieved by combining 5-axis tangent machining with conical barrel cutters. Additionally, tangential plane machining can produce excellent surface quality and longer tool life.

Aerospace Manufacturing and Designwas given exclusive access to a recent seminar demonstrating this machining strategy for aerospace applications at Grob Systems in Bluffton, Ohio.

To showcase the new method, a Grob Systems G350, 5-axis horizontal machining center (HMC) used Open Mind TechnologieshyperMILL computer-aided manufacturing (CAM) software which enables the technique and Emuge cutting tools adapted for the purpose.

Peter Brambs, Open Mind Technologies director of product innovation, explains the 5-axis machining strategy and use of conical barrel cutters. Since the barrel cutter features radii from 250mm to 1,500mm, it can be used for large step-overs. Thetip onthe barrel cutter can also machine corner radii, so machinists wont need to switch cutters to finish adjacent areas such as rounded interior corners. The conical aspect of the barrel cutter allows the shank of the cutter to tilt away fromdeep pocketwalls, thereby allowing shorter cutters. This makes it possible to use the tools on 5-axis machines with line increments from 3.0 mm to 8.0mm, instead of only 0.2mm to 0.4mm with a conventional ball-nose end mill, while achieving the same or better surface quality. Increased step-over also saves cutting time.

Five-axis machining makes it possible to cut challenging geometries, free-form surfaces, and deep cavities more efficiently, Brambs says. The CAM system generates tool paths automatically with automatic collision checking and avoidance.

The Grob G350 is compact, rigid, and offers many spindle and table configurations. The 5-axis model, with A/B table, enables single setup machining of five sides; complex, 5-axis simultaneous 3D surfaces; and multi-angled holes, forms, and profiles.

To work with the software, the machine includes acceleration-dependent, feed-forward control; a load-sensitive drive control; an optimized spindle design, drive unit,work space, and trunnion table.

The machine complements the CAM system by allowing linearized tool paths and the ability to reach programmed speeds faster with greater accuracy. While some large machines are fast only on straight lines, smaller machines can be more agile, optimizing the softwares performance.

Rapid machine movements also reduce the time spent not cutting, notes Stefan Moessmer, a Grob aerospace specialist.

The G350s slim spindle and symmetrical milling headoffershigh cutting-volume rate, less interference, and retraction into a tunnel to reduce the chance of collisions. The horizontal spindle design optimizes chip disposal during pocket machining. The machining centers chip conveyor is positioned directly below the trunnion table to speed chips away from the workpiece, toward the chip disposal at the machines rear.

The 31.69 Z-axis stroke and three roller guide carriages for each guideway maximize stiffness. The tool axis (Z) damping performance is supported by having the motorized spindle guided along the Z- and X-axis, reducing vibration on tooling and the machining center.

The 15.7 square table offers space for 5-axis machining, with part access enhanced by the A-axis tilting range of 225.

Achieves optimal tilt angle against plane being machined

Improves surface quality: lowers roughness values 5x to 10x compared to conventional ball-nose end mills

Finishes hard-to-reach planes without collisions

Removes more material faster while smoothing cusps

Increases tool life, uses fewer tools

Tangential tilt angle for constant tool engagement, machining forces

Open MindshyperMILL MAXX Machining performance package has modules for roughing, finishing, and drilling. It also enables the 5-axis tangent-plane machining strategy.

Roughing includes cycles for trochoidal tool path milling for high-performance cutting (HPC) of prismatic and curved component faces. Dynamic feed rate adjusts according to cutting conditions for maximum material removal, and algorithms remove a constant chip volume to reduce tool stresses and increase roughing speeds 20% to 70%.

The finishing module includes pre-finishing and finishing of planes and free-form surfaces with various barrel cutters. The surface finish depends on the step-over distance and barrel radius. The quality of a workpiece surface decreases as the line increment increases and improves as the tool diameter gets larger. Since the tool shank diameter can only be increased within the limits of the machine tool, barrel cutters only work with a section of the desired tool diameter a circle segment. Larger step-over distances can be realized due to the bigger radius to achievehigh-qualitysurface finish. The barrel cutter has single-point contact with the surface and has better cutting characteristics than swarf milling with the entire side profile of a cutter.

Managing director of Open Mind Technologies Alan Levine notes thehyperMILL MAXX Machining finishing process has been extended to other geometric shapes, such as ruled, curved surfaces.

Conical barrel cutters can machine geometry that is either too tall for efficient swarf milling or too tall for fast cutting with ball mills, such as aero-engineblisks.

In 5-axis helical drilling, holes can be machined with a forward lead angle. Tilting the angle to the side helps avoid collisions. For planes that do not need to be machined simultaneously or on large machine tools, the finishing module can also produce tool paths for 3+2 indexed machining. Only one tool is needed for different drill diameters, pre-drilling is not necessary, and the strategy supports hard-to-cut materials.

The programming process is easy by only selecting planar surfaces and having the system automatically detect boundaries, edges, and other features. Existing customers have implemented this new technique within an hour, Levine says.

Emuge Corp. circle-segment end mills, which Open Mind engineers describe as conical barrel cutters, enable more material removal with fewer passes in 5-axis machining, reducing cycle time up to 90% and providing smoother surface finishes.

Used for machining turbine blades, impellers,blisks, and in mold-making applications, the tools feature large radii in the cutting area of the mills, allowing a larger axial depth of cut during pre-finishing and finishing.

The solid-carbide end mills come in barrel-shaped, oval form, taper form, and lens shape geometries. Oval and taper form mills are for curved shapes such as blades or straight-walled pockets, engaging more of the cutting edge.Barrel shapedmills provide flank milling to the sides of spiral grooves, while lens shape mills excel in narrow channels.

Open MindshyperMill CAM software computes the geometries of circle-segment end mills to achieve the tools design performance.

Traditional ball-nose end mills can prevent the tool from fully accessing features on workpieces. With a conical barrel cutter, the radius is ground along a cone angle relative to the cutter axis, offering better accessibility into deep pockets. Conical barrel cutters also reduce step-overs and the need to polish planar surfaces.

Conical barrel cutters have a larger radius, which has been increased from 250mm to 1,500mm.

Path distances of 6mm and 8mm are possible, producing optimal surfaces and longer tool life. Conical barrel cutters can be applied to generalized surfaces found in landing gear, engine casings, and engineblisks.

Open Minds Levine points out that using standardized programming applications together with conical barrel cutters offers benefits including:

The large radius that can be ground on a conical barrel cutter is greater than on a standard end mill

Shorter cutters allow tool holders greater

With growing pressures in aerospace to reduce production times and increase efficiency, advanced manufacturing methods can help reach those goals. The development of innovative tool paths enables cutters to perform better and faster, and using a machine optimized for the task can reduce machining times and increase tool life. These advantages offer manufacturers a better way to compete for aerospace business.

About the author: Eric Brothers is senior editor ofAM&Dand can be reached at 216.393.0228 .

CommentsEMO Hannover Machine Tool roundtableFeatures – Emo Hannover

Leaders from top machine tool manufacturers discuss the future of the aerospace industry, the industrial economy, machine connectivity, and other trends at the EMO forum hosted by Kennametal.

Robert SchoenbergerHardinge Grinding Vice President and Kellenberger Grinding Machines CEO Urs Baumgartner (left), Fives Machining Systems Inc. President and CEO Steven Thiry, Index Corp. President and CEO Tom Clark, DMG MORI Executive Board Member Björn Biermann, and Mitsui Seiki USA CEO Robb Hudson (right).

During the EMO Hannover 2017 trade show an event that drew more than 2,200 manufacturing technology exhibitors and 130,000 attendees Kennametal and GIE Media,parentcompany ofAerospace Manufacturing & Design,gathered leaders of machine tool companies to discuss 2018s outlook and Industry 4.0.

Were seeing tremendous strength in the aerospace sector, particularly with the tiered suppliers, and especially with the tiered suppliers working on engines. Fives Machining Systems Inc. President and CEO Steven Thiry,

Its generally a very optimistic market. Our main market outside of our domestic market in Japan is aerospace, and with a record backlog or aircraft yet to be delivered and engines to be built, were very optimistic. And were already looking forward to 2019 production because for 2018,werelargely sold out for many of our large, application-specific machines. Mitsui Seiki USA CEO Robb Hudson,

That optimism, however, is not universal.

Boeing has notified its supply base at the last supplier conference that we have enough capacity to fulfill the current build rates. And Boeing now has announced that it will not go beyond the 50-to-55 planes per month build rate. There were plans to go to 60 or 70, which has trickled off.

I am not really optimistic beyond 2017 and 2018. Starrag Group Vice Chairman Frank Brinken,

Were heavily focused on and we still remain very excited and bullish on aerospace because we feel theres still a lot of uncertainty in the marketplace on the supply chain. Its also very evident that around the world,defenseis starting to ramp up. Thats leading to more and more specialty applications for unmanned aircraft, sophisticated surveillance equipment, improved and enhanced missile systems, and guidance technologies. Mitsui Seiki USA CEO Robb Hudson

Just 1% of aircraft components are made in China. If you go 15 or 20 years back, it was the same for automotive components. I have no doubt that in 5, 6, 7, 8 years, they will make 30% of aircraft components worldwide. Maybe not for Airbus or Boeing but for their own aerospace industry. WFL Millturn Technologies Board of Management Member Guenter Mayr,

However, optimism for the market may not translate into more machine sales.

Many of our machine tools that were put into the market 10 or 12 years ago, we are repurposing with newer technology to where their output is 15% to 20% more than when they were new. Thats a very different change in the industry where if you go back many yearsago,when you rebuilt a piece of equipment, you brought it back to new. Today, we bring it back to beyond new because of new technologies. Its causing many of our customers to rethink their CapEx approaches. Fives Machining Systems Inc. President and CEO Steven Thiry

Changes to the global economy had been the cause of great concern in early 2017, but many of those worries have eased in recent months.

Mazak Corp. Chairman Brian Papke ( says President Donald Trump introduced uncertainty in early 2017 as global leaders assessed how his America First policies would impact trade barriers, immigration, defense spending, and other topics. His bite is sometimes a little softer than his bark. And I think were coming to realize this.

DMG MORI Executive Board Member Björn Biermann ( adds that the European market looks healthier than it did at the beginning of the year. With nationalist political wins in Great Britain, there had been some fear that elections in the Netherlands, France, and Germany would bring anti-trade policies to the mainstream, but more centrist candidates won each of those elections. There was a risk that the European Union itself would break up, and this would have a negative

customer demand for the whole European Union. But currently, theres no concern that the European Union market wont be stable.

Index Corp. President and CEO Tom Clark (

says the increase in global stability is improving confidence. When you look at our customers deciding on buying an expensive piece of machinery, they need to have the confidence three and five years from now that they can fill that machine. What weve seen over the last six months is a renewed confidence that theres going to be a business-friendly climate.

Machine tool builders discussed the pros and cons of this rapidly growing market. A few highlights of the discussion include:

Additive is here, but the question is which place in the manufacturing world will it take. It will find its place. How big it will be, nobody knows. Will it be as big as milling? No. will it be as big as EDM? Maybe.

Starrag Group Vice ChairmanFrank Brinken

Drilling, boring, milling, grinding. In 10-20 years, theyll still be the dominant technologies. In the repair business, it makes sense to make something with additive technology, but this is a niche market.

WFL Millturn Technologies Board of Management MemberGuenter Mayr

A lot of the dialog is pitting additive against subtractive machining, and I think thats wrong. The additive market is going to be a completeshift onhow we design and bring products to market, how we can design new, complex parts that you couldnt previously do. Subtractive will always win on a cost-per-piece basis.Additiveis moving and progressing, but its going to do that by changing the entire product design-to-market process, not replacing subtractive machining.

Index Corp. President and CEOTom Clark

Its impossible for us to predict whereadditiveis going to go. Because its changing so fast. Parts have to be redesigned before we can use this technology. That transformation takes a considerable amount of time to do. Theres absolutely room for both or for hybrids that bring both together.

This is an area that can only continue to expand. The more data you have, the more you can mine that data, the more you make good decisions.

In aerospace, there are a lot of constraints on how you can pull that data out and how you can access it. You cant simply connect everything asreadilyas you can connect everything in your office environment. Fives Machining Systems Inc. President and CEO Steven Thiry

I dont think most companies are ready for the full IIoT solution at this stage. But they are ready to start. We have furnished thousands of adapters for machines.

Were going to see many more different types of solutions.

Especially with aerospace manufacturing, difficult-to-cut material use is on the rise, and tool builders say that trend will only grow:

The farther you go into (titanium and heat-resistant super alloys), the more critical it becomes to optimize not just your machine but the cutting tools and everything else involved. Working with metals like that is a lot like a racecar. A general car with a general engine goes down the road real nice, but if you want to turn in an Indy track at 200mph, its all got to be tuned. You cant take an out-of-the-box piece of equipment, be it machine or cutting tool, and not optimize it if you want performance.

Fives Machining Systems Inc. President and CEOSteven Thiry

In the past, we dealt with simply programming the tool to remove the material in front of it. Now we really look at the depth of cut to makeconstantengagement, especially with titanium, to maximize tool life. You can go fast, you just cant go long.

Index Corp. President and CEOTom Clark

There is aninnovationstep on the tool side probably every five years. When youre designing your machine tool to last 15 years, you have to anticipate what these guys will come up with.

Starrag Group Vice ChairmanFrank Brinken

You have to set the machines up in a particular way for nickel alloys versus titanium. A lot of customers think high-speed machining means high volumetric removal rates, and theyre not necessarily the same thing. Its incumbent on us, together with our cutting-tool partners, to do a better job of educating the customers and manage expectations.

This isnt something that could be avoided. We need to embrace it and keep moving ahead. Mazak Corp. Chairman Brian Papke

Along with that optimism were some words of warning.

This data creates a lot of noise, and that noise can create a lot of distraction. If you dont know what to focus on to prove your manufacturing processes, that noise gets in the way. So, you have to be very, very careful in what it is that youre looking at, what youre analyzing, and what corrective actions youre going to put in place

Were facing fewer and fewer capable people at our customer sites that are able to actually act on the data theyre collecting and make sense of it.

It should fall more in the industrial control suppliers Fanuc, Siemens to help us standardize and come up with a standardized solution. Because if werely uponour customers with the skills gap that were facing, were going to end up creating some severe bottlenecks in manufacturing. And instead of our customers enjoying increased spindle uptime and productivity, its going to drive it in the other direction. Mitsui Seiki USA CEO Robb Hudson

Industry 4.0 is a great marketing vehicle. In all of our companie.