Motorsports parts supplier announces manufacturing operations beyond auto racing.
After more than 15 years of outfitting race teams with high-performance parts, Don Schumacher Motorsports Precision Manufacturing (DSM), Brownsburg, Indiana, is expanding into the automotive, defense, equipment/manufacturing, and aerospace industries.
Established in 2005, DSM was founded as a specialty parts manufacturer and R&D center for Don Schumacher Racing's (DSR's) fleet of championship-winning NHRA race cars, and has since grown to become one of the leading parts suppliers for race teams competing across multiple motorsports industries. Among its most high-profile projects are the DSM engine block and cylinder head assembly, used across the DSR teams, and a collaboration with Mopar, SRT, and BES Racing Engines to offer a variety of parts and components for the Mopar Dodge Challenger Drag Pak race car. DSM is heavily involved in the NHRA's popular Factory Stock Showdown Series, offering on-site parts support to Drag Pak owners, and was instrumental in Leah Pruett's 2018 Factory Stock Showdown Series title campaign.
"For years, top race teams have trusted us to make parts they could rely on," said DSM Vice President Chad Osier. "We are manufacturing 11,000hp powerplants that go from zero-to-330mph in less than 4 seconds; this is a real testament to our focus on quality, precision, and talent.
"We originally launched DSM as the manufacturing arm of DSR so we could guarantee quality-control by producing key engine components in-house. Other teams took notice and before long, we were producing parts for them, too. We're thrilled to now be able to offer that same level of high-precision manufacturing and customer service to organizations that operate outside of the motorsports realm."
DSM operates out of a 20,000ft2 facility adjacent to DSR in suburban Indianapolis. Its state-of-the-art machining capabilities include 5-axis milling, multi-axis turning, and Swiss turning, supporting prototyping, short-run, and full-production projects. With 25 high-speed machines and a dedicated engineering and quality team, DSM offers customers quality part solutions with end-to-end support and on-time delivery.
DSM's strategic partners include Okuma (machining), Sandvik Coromant (tooling), Mastercam (programming), Stratasys (3-D printing), and Hangsterfer's (cutting fluid).
DSM is ISO 9001: 2015, ITAR, NISPOM Certified.
During July's Virtual Cutting Tool Roundtable we had so many questions from attendees we weren't able to get to answer all of them. So, our panelists have taken the time to answer those questions and below you will find their insight.
During July's Virtual Cutting Tool Roundtable we had so many questions from attendees we weren't able to get to answer all of them. So, our panelists have taken the time to answer those questions and below you will find their insight.
1. Regarding manufacturing process improvements: What are your customers doing specifically to test new tools used in production under new parameters to ensure they are getting the most productivity throughput (tool life and MRR) out of these new cutting tools? Are they facing downtime to make manufacturing process improvements or do they have extra capacity for R&D?
CGTech – Jeff Voegele, VERICUT Product Specialist: It’s CGTech's belief there is a lot of testing that can be done in a 3D digital simulation environment with a new or modified NC program as well as new tools for figuring out tool life, material removal rate (MRR), along with many other aspects of the programming process prior to actually going down to the shop floor. Minimum extension from holders can be optimized for minimum extension from holders, ensuring the most rigid cutting tool assembly possible. Clearances can be checked to ensure there are no collisions with anything that may come into play during the machining process. Proper feeds and speeds can be verified during the simulation process to make sure you are getting the most out of your cutting tools.
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: This really varies widely. Some customers cannot interfere with the current production and testing either needs postponed or evaluated elsewhere. OSG has the capabilities to test offsite and provide test documentation to the end user for such circumstances.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: Our customers generally use one of the following four options to test new tooling and machining strategies.
2. When will we have proven tool libraries for Mastercam?
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: Sandvik Coromant has introduced a software solution called CoroPlus Tool Library that is designed specifically to manage the tool data requirements of any CAM system. In fact, integration to the Mastercam platform has already been accomplished making these two systems work seamlessly together. The CoroPlus Tool Library solution is based on the ISO 13399 standard which makes it tooling brand agnostic, meaning that you can use this to manage tooling data from any tooling brand that adheres to the ISO 13399 standard. For more information, please contact your Sandvik Coromant representative or visit the following website https://www.sandvik.coromant.com/en-us/products/coroplus-toollibrary.
3. What kind of challenges do you see coming from the use of high speed spindles, cutting tool wise, machine tool software and capability wise?
CGTech – Jeff Voegele, VERICUT Product Specialist: Cutting tools are ready for the challenge of high speed machining with high speed spindles.
Software is also up to the challenge with adaptive type milling and optimization tools like VERICUT Force.
Some of the real challenges are to get CNC programmers to use tool motion methods that are ideal for the cutting tool. Meaning that the correct (ae) & (ap) are used along with the right SFM (spindle speed for a given diameter tool). Another challenge is getting Machinists to trust that optimized higher speeds and feeds are not only doable but are actually beneficial for machining. CGTech offers charts with their VERICUT Force product that gives NC programmers and machinist data to demonstrate the viability of maximizing the chip thickness while knowing the force, deflection, HP, etc.
4. Is the tool manufacturing industry connecting to design software such as Solid Works / Pro E
CGTech – Jeff Voegele, VERICUT Product Specialist: From CGTech's perspective in the simulation environment there are a variety of methods to get tools to and from CAM and simulation software. This includes SolidWorks and Pro/E (or what is now called Creo). Most major tool management systems have an interface to transfer tools into various CAM/simulation systems. I would also encourage you to check out MachiningCloud as a source to get access to more than 40 tool vendors tooling models for download. The data coming from MachiningCloud can be used directly in CAM and simulation systems as well as put into tool management systems then transferred to a particular system downstream. It is also worth mentioning that now many systems do not just transfer 3D tool geometry, but also includes cutting limits and recommended feed/speed settings to be used with optimization. VERICUT's Force software is one solution that can take advantage of this information to further improve the NC program, tool usage and tool life.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: Today, it is possible to connect CoroPlus Tool Library to design software such as Solid Works and Pro E and this can bring added convenience to importing tool models when checking design for manufacturing compatibility and such. The longer term vision of Sandvik Coromant's CoroPlus platform is to provide much more connectability and capability across the machine shop's value stream which has the potential to build and provide access to much needed system knowledge to the design engineering function, thereby reducing the need to rely solely on local tribal knowledge.
5. If you work at the OEM ordering parts how would you audit / evaluate tool rooms / Selection at supplier versus machine centers?
6. What is (are) the next step(s) on the evolution of cutting tools? Tool substrate? Coating? Edge Preparation? Geometry? Machining strategy?
CGTech – Jeff Voegele, VERICUT Product Specialist: One of the next steps in tooling evolution relating to data is including the tool vendor cutting limits along with the 3D geometry of tools. This information can be used in simulation beyond just verifying the 3D tool works in your application and not causing any collisions but can then be taken as step further to use to optimize your NC program beyond what CAM systems can do. In our partnerships with the various tooling vendors and tool management systems we make sure all that information is being properly managed and transferred for use downstream in the simulation process.
Another area of development is CNC machines streaming data (MTConnect) to give feedback as to what is going on in the machine while cutting a part. Gathering this machine intelligence and then being able to utilize in within a simulation is yet another area where further insight and offer potential recommendations that could aid in machining, increase tool life, or to enhance optimization further.
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: All of the above.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: At Sandvik Coromant, we continue to work on developments in all of the areas mentioned (substrates, coatings, edge prep, geometry, machining strategy). Of particular interest has been combining development of machining strategies in conjunction with cutting tool design to deliver unparalleled perform over traditional development techniques. Our Prime Turning solution is just one example, where we have design inserts and tool holders to perform bi-directional turning applications which were not previously possible with traditional tooling. One other interesting area of development is the embedding of digital technology (sensors and analytics) into cutting tools to provide immediate performance data and the possibility to automate adaptive reaction.
7. How can you monitor tool wear to know when to change a tool.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: Traditional: The traditional method for tool wear/life management is to create an "expected tool life baseline" for each tool on a given machine or component. This is done by observing and documenting over time, how many minutes or components each tool will last. Then these tool life expectations are entered into the tool life tables of the CNC machine's controller, thus allowing the machine tool to alert you when a particular tool needs to be changed or replaced with a redundant tool.
Advanced: Sandvik Coromant offers a solution called CoroPlus Process Control, that integrates sensors and advanced edge analytics technology into a machine tool that provides the capability to actively monitoring the machining process and provide feedback as to the condition (health) of the cutting tool. When a tool is deemed to have reached its usable life, appropriate manual or automated response options (e.g. stop machining and alarm, change to redundant tool etc.) can be enabled to provide both tool security and performance.
8. What are you doing to provide quick supply of tooling? Too often we find the cutters and holders we need and then are told they are 6 weeks to 3 months away when we have a job that needs to be on the machine within days.
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: We offer a service that provides custom taps in a few days, depending on blank availability. We also have 35,000 standard stock items, so give us a call, chances are we have something on the shelf that may work.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: The key to maintaining a healthy and sustainable balance of useful inventory is to have a robust forecasting model that provides the proper inputs into our production and inventory controls models. Of course, one of the key inputs is a more forward picture of the market dynamics and a better understanding of the short, mid and long term tooling needs of our customers. We have been diligently working on improving this specific area of our business as we see it as the key to success for both us and our customers, so we would encourage you to build a close collaboration with your preferred tooling partners. We also believe in and are working towards the long term vision of "The Connected Machine Shop," where the integration of digital technology into the manufacturing space will replace our reliance on static data with automatically collected and analyzed dynamic data to provide more valuable insights into the production and inventory needs of machine shops and their suppliers.
9. What are you doing to support and enhance the Iso Standards for cutting tools. Today the data we need in engineering our manufacturing is critical. Without the models and machining parameters, the best tools are useless. What is being done to download this data directly into our Tooling systems.
CGTech – Jeff Voegele, VERICUT Product Specialist: CGTech is following the ISO 13399 standard with regards to tooling in our VERICUT software. We are also working with tooling vendors and tool management systems to make sure their data follows the ISO standard and reads into VERICUT seamlessly. CGTech has interfaces to all major CAM and tooling systems to allow for easy transfer of the best quality tooling data available.
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: All of our new products launched to market have the data download capability. We are currently in process of creating the prints for all our tools. It is a large endeavor and we are looking at ways to expedite and streamline it. You will see more and more in the near future.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas:
10. Would quick change tool holding take away from the cutting tool's accuracy and grip over a dedicated tool holder?
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: We can’t speak for all brands of quick change tooling but utilization of our Coromant Capto quick change tooling portfolio should not require any reduction of cutting capabilities as compared to traditional "stick" tooling.
11. How often does the impact on tool life that holders can affect, come into your equations for helping customers with selecting the right cutting tool? If so, what does that process look like?
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: The right holder has a huge impact on tool performance, including tool life and part accuracy. I have seen first-hand conventional holders versus high-performance milling chucks/shrink fit and the results are astonishing.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: If I understand the question correctly, we generally always consider the tool holder as a key input to selecting the proper cutting tool for any particular application. The reason is that the holder is the foundation of the cutting tool assembly and how you hold a tool can be the difference between a successful machining application and a failed one. Of course, the more complex your machining applications are (e.g. long overhang, weak setup etc.) the more critical your tool holder selection becomes. This is why we offer a full line of tool holder options, with some that include unprecedented levels of accuracy, bending stiffness, holding power and vibration dampening to name a few.
12. The horsepower in each machine is important to select tool to remove rough or finish operations?
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: Yes, absolutely. It basically dictates what is possible for maximum metal removal rates.
Sandvik Coromant – Jeff Rizzie, Director, Digital Machining-Sales Area Americas: Horsepower is absolutely a key input in selecting the proper cutting tool for roughing applications, however total horsepower alone is not enough. In order to maximize the performance of both the machine and the cutting tool, you should have a good understanding of the machine's torque curve and available horsepower capabilities, which will generally tell you what your maximum spindle capabilities are at any given speed. This information can generally be found in your machine tool's operations or maintenance manuals or through your machine tool provider.
13. What are typical applications for CVD-coated carbide tools?
CGTech – Jeff Voegele, VERICUT Product Specialist: PVD COATINGS TiN – TITANIUM NITRIDE PVD COATINGS TiN - TITANIUM NITRIDEA general purpose coating for HSS, HSCO, and solid carbide end mills that provides effective protection against wear, abrasion, and edge buildup. Primary applications are milling steels in a non-hardened condition.
TiCN – TITANIUM CARBONITRIDE Incorporation of carbon into the TiN matrix to increase hardness and abrasion resistance. TiCN is an alternative to TiN for HSS and HSCO applications where additional wear resistance is required. Primary solid carbide applications are milling aluminum alloys & cast iron.
TiAlN – TITANIUM ALUMINUM NITRIDE TiAlN offers a higher level of thermal stability above Tin and TiCN with abrasion resistance. Ideal for high heat applications found in milling steels, stainless steels and high temp alloys with a hardness 52 Rc and below.
AiTiN – ALUMINUM TITANIUM NITRIDE Increased thermal stability when milling high temp alloys and die/mold steels with a hardness 52 Rc and above. Excellent for HSM applications, titanium, and stainless steels. HSS/HSCO end mills can’t be coated with AlTiN.
AlCrN – ALUMINUM CHROMIUM NITRIDE Excellent wear resistance under conventional and extreme conditions when milling die/mold steels with a hardness 52 Rc and below. Excellent choice for tool steel, alloy steel, and stainless steel applications.
CVD coated diamond tools are Ideal for machining graphite, composites, green carbide, and green ceramics.
OSG USA Inc. – Jeff Stephens, Applications Engineering Manager: For OSG, we excel in CVD applications. For us, the primary market is composite machining. We offer an extensive composite machining lineup for both milling & drilling. CVD can also be applied in graphite machining for electrode machining as well most non-ferrous machining.
SpaceX’s Crew Dragon, carrying NASA astronauts Robert Behnken and Douglas Hurley, splashed down in the Gulf of Mexico.
Two NASA astronauts splashed down safely in the Gulf of Mexico Aug. 2, 2020, for the first time in a commercially built and operated American crew spacecraft, returning from the International Space Station (ISS) to complete a test flight that featured the first splashdown for American astronauts since Thomas Stafford, Vance Brand, and Donald “Deke” Slayton landed in the Pacific Ocean off the coast of Hawaii on July 24, 1975, at the end of the Apollo-Soyuz Test Project.
SpaceX’s Crew Dragon, carrying Robert Behnken and Douglas Hurley, splashed down under parachutes in the Gulf of Mexico off the coast of Pensacola, Florida at 2:48 p.m. EDT Sunday and was successfully recovered by SpaceX. After returning to shore, the astronauts flew back to Houston.
“Welcome home, Bob and Doug! Congratulations to the NASA and SpaceX teams for the incredible work to make this test flight possible,” said NASA Administrator Jim Bridenstine. “It’s a testament to what we can accomplish when we work together to do something once thought impossible. Partners are key to how we go farther than ever before and take the next steps on daring missions to the Moon and Mars.”
NASA’s SpaceX Demo-2 test flight launched May 30, 2020, from the Kennedy Space Center in Florida. After reaching orbit, Behnken and Hurley named their Crew Dragon spacecraft “Endeavour” as a tribute to the first space shuttle each astronaut had flown aboard.
Nearly 19 hours later, Crew Dragon docked to the forward port of the ISS Harmony module May 31.
“On behalf of all SpaceX employees, thank you to NASA for the opportunity to return human spaceflight to the United States by flying NASA astronauts Bob Behnken and Doug Hurley,” said SpaceX President and Chief Operating Officer Gwynne Shotwell. “Congratulations to the entire SpaceX and NASA team on such an extraordinary mission.”
Behnken and Hurley participated in scientific experiments, spacewalks, and public engagement events during their 62 days aboard station. Overall, the astronaut duo spent 64 days in orbit, completed 1,024 orbits around Earth, and traveled 27,147,284 statute miles.
The astronauts contributed more than 100 hours of time to supporting the orbiting laboratory’s investigations.
Behnken conducted four spacewalks while on board the space station with Expedition 63 Commander and NASA colleague Chris Cassidy that included installing lithium-ion batteries, power and Ethernet cables, and a protective storage unit for robotic operations. They also removed shields and coverings to prepare for the arrival later this year of the Nanoracks commercial airlock on a SpaceX cargo delivery mission.
The Demo-2 test flight is part of NASA’s Commercial Crew Program, which has worked with the U.S. aerospace industry to launch astronauts on American rockets and spacecraft from American soil to the space station for the first time since 2011. This is SpaceX’s final test flight and is providing data on the performance of the Falcon 9 rocket, Crew Dragon spacecraft and ground systems, as well as in-orbit, docking, splashdown, and recovery operations.
Crew Dragon Endeavour will return to SpaceX’s Dragon Lair in Florida for inspection and processing. Teams will examine the spacecraft’s data and performance from throughout the test flight. The completion of Demo-2 and the review of the mission and spacecraft pave the way for NASA to certify SpaceX’s crew transportation system for regular flights carrying astronauts to and from the space station. SpaceX is readying the hardware for the first rotational mission, called Crew-1, later this year. This mission would occur after NASA certification, which is expected to take about six weeks.
Dragon Endeavour is lifted out of the waters of the Gulf of Mexico and onto the SpaceX “GO Navigator” recovery vessel. Image credit: NASA TV
This report documents the design process of a Fuel Cooled Oil Cooler (FCOC) from initial design in CAD, process steps in nTop Platform, and final Computational Fluid Dynamics (CFD) analysis steps in ANSYS CFX.
By Maiki Vlahinos and Ryan O’Hara, nTopology
Using nTopology’s advanced geometry kernel it is now possible to produce a next generation high-performance Heat Exchanger (HEX) for the aerospace industry, as shown in Figure 1, using advanced materials and manufacturing methods. When coupled with ANSYS CFX, the evaluation of high-performance designs can be achieved in ways that were not previously possible.
Figure 1: Triply Periodic Minimal Surface high performance HEX for applications in aerospace turbine engine applications
In aviation, thrust is required to propel air and space-craft through the atmosphere. The engine combusts fuel and extracts mechanical work from this combustion to generate the thrust required for flight. In all engines, the process of combustion and mechanical work produces excess heat that must be dissipated. Specifically, the oil in the engine needs to be cooled to maintain the lubrication of components that rotate within the engine. In modern aircraft, the fuel spends much time stored in the wings, where it gets extremely cold. As such, it can be used to cool many of the subsystems of the aircraft. A FCOC exchanges heat between the engine oil and the fuel in such a manner that the engine oil is cooled whilst the fuel is heated up. This exchange of heat serves two purposes: the cooled oil properly lubricates the engine while heating the fuel prevents the formation of ice crystals within the fuel.
The design shown here was inspired by an America Makes project where it was required to leverage additive manufacturing on a legacy shell and tube HEX for both part replacement and to discover whether advanced design and manufacturing could be used to increase the performance of the legacy component shown in Figure 2.
Figure 2: American Makes Fuel Cooled Oil Cooler in a shell and tube HEX configuration.
Delivering Increased Thermal Performance In Space-Constrained Volume
Many aerospace capabilities are built upon hardware platforms that often cannot be changed without serious modifications. As such, it is imperative that design engineers are enabled to do more with less. One way this can be achieved is by using an advanced geometry representation to mathematically and precisely control the geometry within the interior volume of the design space. In this example, nTop Platform was used to define a volume that could be used to iteratively design a modified FCOC that maximizes surface area while minimizing mass (thickness) of its interior walls. With these constraints these are the only two ways to increase the performance of a HEX.
Heat transfer through a wall can be calculated as:
And the Heat Transfer Coefficient (HTC) is:
k = thermal conductivity (W ) (3) s = material thickness (m) (4)
Maximizing surface area can be accomplished by utilizing a Triply Periodic Minimal Surface (TPMS); one known as a gyroid, which has both a high strength to weight ratio and very high surface area to mass ratio, is used in this case study [Gyroid = S in(x)Cos(y) + S in(y)Cos(z) + S in(z)Cos(x)]. By using a gyroid structure in the HEX, a 146% increase in surface area was achieved when compared to a more traditional tube-and-shell HEX of the same size. When coupled with advanced manufacturing methods, these TPMS structures enable parts with both high-strength and heat-dissipative requirements to be designed in a manner that was previously impossible to achieve.
To minimize the wall thickness of the HEX, a cutting-edge nano-functionalized high-strength 7000 series aluminum alloy (7A77), that has been developed specifically for additive manufacturing, was chosen for fabrication. Through the increased strength of this alloy the wall thickness of the FCOC was minimized while still meeting critical burst-pressure structural requirements of the aircraft. With nearly twice the yield strength of AlSi10Mg (a traditional cast grade aluminum alloy for AM) the walls of the gyroid can now be approximately half the thickness of previous designs. By using nTop Platform to design the internal core with a gyroid structure it was possible to increase the surface area by 146% and reduce wall thickness by half, which increased the overall heat transfer of the FCOC by approximately 300% within the same volume as the legacy design.
Computational Fluid Dynamic Simulation for Predicting Performance
ANSYS CFX, an advanced computational fluid dynamics solver, was utilized to evaluate the performance of the FCOC. Throughout the design iteration phase several CFD simulations were used to evaluate the design. Driven from initial simulation results it was possible to redirect how the energy was being distributed inside the gyroid, thereby increasing the total heat-transfer coefficient by an additional 12%. A repeatable workflow was developed from nTop Platform into ICEM (for mesh refinement and conversion) and ANSYS CFX, aiding in rapid design iteration.
Figure 3: HTC values with the oil velocity streamlines are shown in the color map on the left with fuel HTC while the color map on the right shows the fuel velocity streamlines with the oil HTC.
Fuel and oil fluid properties and boundary conditions at mass flow rates of approximately 0.45 k g /s and 0.3 kg/s were used respectively. The left image in Figure 3 shows a contour plot of the heat-transfer coefficient inside the fuel domain as well as the streamlines of the oil. The image on the right in Figure 3 depicts a contour plot of the heat-transfer coefficient inside the oil do-main with fuel streamlines moving through the gyroid. With a gyroid core that is only about 100mm (3.9in) in height and 60mm (2.4in) in diameter the overall performance was 3KW (10,200 Btu/Hr).
Now we will focus on the procedural steps that were used to deliver the advanced capability that was previously described. The process for translating geometry from nTop Platform to the chosen CFD tool is summarized by the process shown in Figure 4. The process is defined by the user isolating the fluid domains of the HEX, producing volume meshes of these fluid domains in nTop Platform, and then importing these fluid-volume meshes into the CFD tool, applying the appropriate boundary conditions, and then solving the fluid simulation.
Figure 4: This flow chart depicts the process workflow necessary to get into CFD from nTop Platform. It can be used for a single or multi fluid domain HEX.
The initial design concept for the FCOC went through several iterations on paper as well as in Computer Aided Design (CAD) before entering nTop Platform. The main design considerations were: minimizing pressure drop, enhancing flow characteristics, introducing impingement to improve the HTC, and design for additive manufacturing. As shown in Figure 5, hot oil enters the top pipe (1), moves around the blue dome, enters the gyroid (depicted as a red cylinder), enters the inner diameter and exits out the pipe at the bottom (2). The cold fuel enters through the bottom left opening (3), impinges on the oil outlet pipe, moves up through the gyroid, impinges on the blue dome and exits top right (4).
Figure 5: Original design concept of the Fuel Cooled Oil Cooler (created & depicted in Creo)
The CAD bodies and surfaces seen in Figure 5 were used to define the volume of the HEX and then leveraged to design the infill volume for a TPMS structure. The sketcher and revolve tools in Creo were used to generate the outer shell and dome structures of the HEX.
Heat Exchanger Design Using nTop Platform
After the boundary representations were finalized in Creo, the assembly was saved as individual parasolids and the bodies were imported into nTop Platform. Once imported, in order to properly leverage CAD geometry in nTop Platform, it was necessary to convert the part(s) to an nTop implicit body.
nTop Platform has the unique capability to create TPMS structures in a Cylindrical Coordinate system, Figure 6. This is beneficial to HEX design more broadly and fluid flow in particular. The ability to create these structures in a Cylindrical Coordinate system is also beneficial because you get a symmetric/uniform shape that is circumferentially continuous, as opposed to the gyroid structure that is created in a Cartesian Coordinate system. These gyroid structures are also self-supporting and lend themselves to not only being structurally and thermally efficient, but also readily fabricated in a variety of AM processes without the need for additional support structures during the building process.
Using nTop Platform we can vary the circumference count, radius & height periods, cell size and wall thick-ness of the gyroid to meet the design requirements of the HEX as shown in Figure 6. With that level of control, the designer can tailor the shape of the gyroid to meet performance requirements such as surface area and cross-sectional flow area. This geometric control also allows the designer to adjust the way the fluid will enter and exit to minimize overall pressure drop while optimizing the system-level performance of the HEX. Figures 7, 8 and 10 show how the cell size, circumference count, and height period can be adjusted to achieve a smooth fluid passage throughout the HEX.
Figure 7: Comparison of the fuel exit geometry from the gyroid core
Figure 8: Comparison of the oil exit geometry from the gyroid core
Figure 9: Various inlet configurations were considered to maximize flow and manufacturability of the HEX during the design process.
Figure 10: A comparison of two gyroid designs where the cell size, circumference count, and height period are constant but with the radius period varied. The image on the left encourages the oil to not fully enter the gyroid but rather go straight down the outer shell. Whereas the image on the far right encourages the oil to flow into the gyroid.
Up to this point we have imported and converted our CAD geometry into nTop implicit bodies and generated our fluid domains. The next step in the design process of the HEX will be to create the baffles or flow diverters. These keep the two fluids from mixing. A simple Boolean Intersect block is used to create the baffles. The primary challenge in this step is generating the volumes used to intersect with the fluid volumes. This may require the designer to convert extra CAD entities (faces, edges, vertices) as well as assign parametric control parameters so that as the CAD geometry changes the workflow will be repeatable. Once the intersecting volumes have been generated it is just a matter of selecting the appropriate fluid to block out.
The majority of intersecting volumes were created from extracting CAD surfaces, which were converted to nTop implicit bodies and thickened. The other intersecting volumes used primitive geometry blocks to generate new geometry. The primary block used was the torus, which was then remapped, to create an arched passage way, as shown in Figure 9, that produced a structure that was more amicable to additive manufacturing. Figure 11 depicts the blocks & steps associated with generating the baffles for the FCOC.
Figure 11: This screenshot depicts the nTop Platform blocks that form the gyroid core and fluid volumes. These numbered “parent” blocks require inputs to be complete. These inputs are other blocks and/or general input parameters that control the design and influence the performance. Block (1) Gyroid Core New creates HEX core, block (2) Fuel Fluid New creates one fluid domain and block Oil Fluid New creates the second fluid domain using a Boolean Subtract of Blocks (1) and (2) from the original body used to create the volumes.
Now that the process of creating the baffles is completed, it is necessary to assemble the newly formed HEX core to the components of the HEX. A Boolean Union is used for these operations. During this process, nTop Platform can seamlessly create a fillet between the periodic baffled structure and the “solid” geometry, in this case, the outer shell that was previously drawn in Creo.
At this point in the design, the validation and verification process begins. Finite Element Analysis (FEA) and CFD can be part of the simulation validation and are often used as a precursor to experimental testing. The discretization of nTop Platform implicit geometry for use in a CFD simulation will be described in this section.
As previously described in Figure 4, now that the fluid domains and HEX walls have been generated it is necessary to generate a volume mesh of these regions. Meshing these volumes is achieved through a relatively simple combination of blocks that discretize nTopology’s native implicit-geometry representation into a series of surface triangles and volume tetrahedral elements as shown in Figure 13.
After meshing is complete, the volume meshes can be exported as an ANSYS Fluent mesh (a CFD mesh file type option available from nTop Platform) and imported into ICEM CFD, an ANSYS module used for mesh refinement, conversion, and as a boundary selection tool. Depending on the type of physics being solved, a user would typically choose either CFX or Fluent solvers. For example, Fluent is preferred for high-mach numbers/supersonic flow while CFX is preferred for turbo machinery and other incompressible flow simulations. In order to set up and define any type of computational analysis, the user must apply boundary conditions to select surfaces. These include, but are not limited to, the fluid inlet and outlets faces. Within ICEM we are able to select individual elements. This allows the user to select the surfaces for boundary conditions. Another example of a boundary condition would be a symmetry plane. A very useful reason for selecting faces is to apply boundary layer meshes and perform simple mesh refinement at a localized area.
Figure 12: This is a depiction of the ANSYS Workbench Schematic for the fluid simulation analysis. ICEM CFD and ANSYS CFX were used to perform the final simulation.
Figure 13: The meshing process inside nTop Platform. On the left of the image is the model tree which depicts the blocks used to create and export the mesh. In the center is the mesh of the HEX core and on the top right of the image is the export window with ANSYS Fluent as the format option.
When the boundary faces are defined and the meshes converted, each fluid domain is imported separately into ANSYS CFX. The faces defined are recognized and can easily be assigned to their proper boundary condition. The fuel and oil inlet mass flow rates were set to 0.45 kg/s and 0.3 kg/s respectively with 0 kPa outlet.
Once the nTop Platform-to-CFD-workflow has been set up you can continue to utilize it throughout the design iteration process. Mesh outputs from nTop Platform can be recognized in ICEM as the design updates, which can then be re-imported and the entire CFD work-flow repeated.
The overall feasibility of performing CFD on complex geometry generated in nTop Platform has been demonstrated. nTop Platform allows the user to create complex geometries (TPMS structures, fluid volumes, smooth lattice-solid transitions), while maintaining complete control over the geometric model, and then easily allows the user to export the geometry outside of nTop Platform for validation and verification. The ability to do such complex operations in a single tool while integrating with external CAE tools is unprecedented and can allow for rapid design iterations to be achieved on complex geometry.
Linear pallet storage system provides highly automated flexible part machining.
By Derek Schroeder Universal Machines Sales, Supervisor – Proposals & Applications, GROB Systems Inc.
Industry is moving inexorably towards automation, in which unmanned machines can increase productivity while reducing waste. Prior to 2015, about one in ten 5-axis universal milling machining centers sold by GROB Systems Inc. featured automation, but now nearly half do. Subject to pressures to reduce scrap and increase throughput, smaller job shops often lack the budget for higher end 5-axis machines. Now, new 5-axis machine technology is available to help them evolve in this Industry 4.0 era of machine monitoring and connected machines.
Smaller job shops looking for machining solutions that increase productivity
Smaller job shops are looking for flexible solutions that can be used for every challenge, customer, and market – from medical, aerospace, and automotive, to mold and die and energy. One example of entry level 5-axis machine technology being developed for these smaller job shops is GROB Systems’ new Access Series 5-Axis Machining Center, which offers many of the features of high-end machines but at a price that results in a short payback time.
With the new technology, job shop owners can be assured of getting as much spindle utilization as possible. They can also keep machines running when no one is there. For example, if they are changing a part at first shift, they can keep the machine running without an operator for several shifts, resulting in less cost to the customer. In addition to running automated for production runs, the flexible machine can also be operated in manual mode for part setups, prototyping, or small batch runs.
Three linear and two rotary axes permit 5-sided machining, as well as 5-axis simultaneous interpolation. The axis arrangement provides an extremely large swivel range, larger than most other options for positive angle of solutions. For negative angles, two options give good access to the part without having to make different fixtures and compensate in other ways. This means the largest possible part in the work area can be machined with maximum tool length.
The compact machine concept provides smaller job shops with a small footprint, but with features often found only in larger machines. One key feature is a rigid spindle axis, designed so the machine is most rigid at the part, thanks to an optimally positioned bearing close to the operating point. This rigidity at the part means the machine can remove material faster, with less vibration and a more constant process. The rigidity also reduces tooling costs, enabling operators to be more productive, and increasing the profit from the machine.
Another design feature is a long Z-travel path, which enables tool change to happen outside of the work area. Many other designs require tool change to occur in the work area, which provides a smaller available area for the part. The new machines provide 1,020mm of Z-axis travel – the longest in this machine class – while other competitive machines range from 400mm to 650mm.
Active cooling of heat-absorbing components and assemblies makes for efficient machine cooling, and a unique overhead machining function offers excellent chip fall and reduced thermal load in the component. Operators can choose between Siemens and Heidenhain machine control systems.
The reference axis’ linear guidance system can be equipped with a temperature-controlled cooling function, and a wide-opening work area door ensures safe and ergonomic access. The machining process is viewed through a laminated safety glass.
Most flexible job shops need tool storage capacity, and the new technology offers a variety of options for storing tools inside the machine. The single disk option enables job shops to hold approximately 50 tools around the outside of the disk; the double disk option increases tool capacity without making the machine bigger.
The machine uses GROB’s Swivel Axis Calibration (GSC) technology to find and compensate for volumetric errors. Unlike other technology that can compensate for four positions/compensation points using the controls, GSC is freely definable and can compensate for 40-50 positions/compensation points.
The entry level 5-axis technology can run on the same platform as other machines, which can all be connected to the same automation. Since operation across the range of machines is identical, operators and maintenance staff already have familiarity, making transition easier.
Linear pallet storage system with low investment
The entry level 5-axis machine technology is available with a linear pallet storage system (PSS-L) that can be used for a wide variety of part types. Flexibly configurable according to user requirements, the PSS-L provides a complete solution from a single source in a standardized design and an interface optimally matched to the machine.
The PSS-L is a modular system for individual machines or for interlinking the same machining systems. It can be used with different machine types, numbers of machines, and numbers of setup stations. Users can customize the mechanical layout to make it fit plant or part requirements and can customize the software. For example, if the user has a database for tracking fixtures or tooling offsets, the machines can communicate with the database and control that data. Up to five machine tools can be connected to pallet storage racking with a maximum of 87 pallet positions. The PSS-L can also operate as an independent machine.
The PSS-L provides a longer and unmanned production period and allows optimum access to the machine’s work area during automation, for example for manual loading or setup work.
Customers can connect a mix of machine types on one line, keeping all operations in the same system, performing them all in the same cell. For example, they may perform part turning operations first, then move to a milling-only second operation. If they want to segregate operations between machines they can do so. The key is that they do not have to remove the part from a lathe for turning and then move the part over to the linear system.
The PSS-L features a linear traveling pallet changer system with a pallet gripper to transport the
materials between setting stations, work-piece deposits and machines. It does not use any cable track and the pallets are staged close to the machine to prevent long exchange times. An easily accessible setup station features crane loading capability.
The system also comes with production control software, so users have a simple, intuitive organization of pallets and parts with associated process steps. Customers can have autonomous part and pallet control while considering resources, along with monitoring and verification of tool resources for all scheduled orders.
The new technology was launched in September 2019 and is already being used in Europe and Asia. One example is an aerospace repair center in Poland, which did not have the budget for a larger machine and is using the new unit for engine repairs and overhaul. A UK aerospace manufacturer purchased a unit because they liked the idea of getting all their machines from one supplier. They had several large GROB machines and will use the smaller units to automate all the existing machines, which are used for manufacturing aerostructure parts. A mechanical engineering firm in Germany looking for a lower cost solution opted for the Access unit to manufacture parts for their own automation products. A final example is a die and mold shop in Germany, which purchased a unit as a lower cost alternative to the higher cost machines they already had on their production floor. The unit is being used for manufacturing of injection molds.
The new Access Series 5-Axis Machining Center and PSS-L automation technology will be available in North America by summer 2020. The machines are being built in the Bluffton, Ohio manufacturing facility.
Users opt for a single system to navigate challenging automation issues
Automation often involves many issues that may be difficult to navigate. Many are looking for one supplier that can furnish all required equipment, rather than one supplier for automation and one machine tool builder for the machine. The new machining center and linear pallet storage system fits the bill, with one supplier supporting an entire system that is ideal for increasing unmanned operation and reducing scrap and waste.