Webinar on Demand: Make Functional Prototypes More Economically with 3D Printed Injection Molds

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Make Functional Prototypes More Economically

With 3D Printed Injection Molds

Arad Group
3D printed injection molds created by Arad Group

One of the most dramatic impacts of 3D printing on design and manufacturing is with injection molding. Companies such as Seuffer, Unilever, Arad Group and Whale report significant savings in molding costs and production time by 3D printing injection molds to test designs before mass production and produce small quantities of custom parts.

Learn more by viewing this 60-minute webinar as Gil Robinson, Stratasys senior application engineer, explains the what, why and how of 3D printed injection molding.

The Additive Manufacturing Software Conundrum

Why are there so many different software solutions in Additive Manufacturing and which ones do I really need?

This was a question I was asked at lunch during the recently concluded RAPID 3D printing conference by a manager at an aerospace company. I gave her my thoughts as I was stuffing down my very average panini, but the question lingered on long after the conference was over – several weeks later, I decided to expand on my response in this blog post.

There are over 25 software solutions available (scheduling software for service technicians, etc.) and being used for different aspects of Additive Manufacturing (AM). To answer the question above, I found it best to classify these solutions into four main categories based on their purpose, and allow sub-categories to emerge as appropriate. This classification is shown in Figure 1 below – and each of the 7 sub-categories are discussed in more detail in this post.

Figure 1. Seven sub-categories of software that are applicable to Additive Manufacturing, sorted by the need into four main categories

Basic Requirements

1. Design Modeler

You need this if you intend to create or modify designs

Most designs are created in CAD software such as SOLIDWorks, CATIA and SpaceClaim (now ANSYS SpaceClaim).  These have been in use long before the more recent rise in interest in AM and most companies have access to some CAD software internally already. Wikipedia has a comparison of different CAD software that is a good starting point to get a sense of the wide range of CAD solutions out there.

2. Build Preparation

You need this if you plan on using any AM technology yourself (as opposed to sending your designs outside for manufacturing)

Once you have a CAD file, you need to ensure you get the best print possible with the printer you have available. Most equipment suppliers will provide associated software with their machines that enable this. Stand-alone software packages do exist, such as the one developed by Materialise called Magics, which is a preferred solution for Stereolithography (SLA) and metal powder bed fusion in particular – some of the features of Magics are shown in the video below.

Scanning & File Transfer

3. Geometry Repair

You need this if you deal with low-quality geometries – either from scans or since you work with customers with poor CAD generation capabilities

Geomagic Design X is arguably the industry’s most comprehensive reverse engineering software which combines history-based CAD with 3D scan data processing so you can create feature-based, editable solid models compatible with your existing CAD software. If you are using ANSYS, their SpaceClaim has a powerful repair solution as well, as demonstrated in the video below.

Improving Performance Through Analysis

4. Topology Optimization

You need this if you stand to benefit from designing towards a specific objective like reducing mass, increasing stiffness etc. such as the control-arm shown in Figure 2

Topology optimization applied to the design of an automobile upper control-arm done with GENESIS Topology for ANSYS Mechanical (GTAM) from Vanderplaats Research & Development and ANSYS SpaceClaim
Figure 2. Topology optimization applied to the design of an automobile upper control-arm done with GENESIS Topology for ANSYS Mechanical (GTAM) from Vanderplaats Research & Development and ANSYS SpaceClaim

Of all the ways design freedom can be meaningfully exploited, topology optimization is arguably the most promising. The ability to now bring analysis up-front in the design cycle and design towards a certain objective (such as maximizing stiffness-to-weight) is compelling, particularly for high performance, material usage sensitive applications like aerospace. The most visible commercial solutions in the AM space come from Altair: with their Optistruct solution (for advanced users) and SolidThinking Inspire (which is a more user-friendly solution that uses Altair’s solver). ANSYS and Autodesk 360 Inventor also offer optimization solutions. A complete list, including freeware, can be availed of at this link.

5. Lattice Generation

You need this if you wish to take advantage of cellular/lattice structure properties for applications like such as lightweight structural panels, energy absorption devices, thermal insulation as well as medical applications like porous implants with optimum bone integration and stiffness and scaffolds for tissue engineering.

Broadly speaking, there are 3 different approaches that have been taken to lattice design software:

I will cover the differences between these approaches in detail in a future blog post. A general guideline is that the generative design approach taken by Autodesk’s Within is well suited to medical applications, while Lattice generation through topology optimization seems to be a sensible next step for those that are already performing topology optimization, as is the case with most aerospace companies pursuing AM technology. The infill/conformal approach is limiting in that it does not enable optimization of lattice structures in response to an objective function and typically involves a-priori definition of a lattice density and type which cannot then be modified locally. This is a fast evolving field – between new software and updates to existing ones, there is a new release on an almost quarterly, if not monthly basis – some recent examples are nTopology and the open source IntraLattice.

Below is a short video demo of Autodesk’s Within:

6. Analysis

You need this if you do either topology optimization or lattice design, or need it for part performance simulation

Basic mechanical FE analysis solvers are integrated into most topology optimization and lattice generation software. For topology optimization, the digitally represented part at the end of the optimization typically has jarring surfaces that are smoothed and then need to be reanalyzed to ensure that the design changes have not shifted the part’s performance outside the required window. Beyond topology optimization & lattice design, analysis has a major role to play in simulating performance – this is also true for those seeking to compare performance between traditionally manufactured and 3D printed parts. The key challenge is the availability of valid constitutive and failure material models for AM, which needs to be sourced through independent testing, from the Senvol database or from publications.

Process Development

7. Process Simulation

You need this if you would like to simulate the actual process to allow for improved part and process parameter selection, or to assess how changes in parameters influence part behavior

The real benefit for process simulation has been seen for metal AM. In this space, there are broadly speaking two approaches: simulating at the level of the part, or at the level of the powder.

  • Part Level Simulation: This involves either the use of stand-alone AM-specific solutions like 3DSIM and Pan Computing (acquired by Autodesk in March 2016), or the use of commercially available FE software such as ANSYS & ABAQUS. The focus of these efforts is on intelligent support design, accounting for residual stresses and part distortion, and simulating thermal gradients in the part during the process. ANSYS recently announced a new effort with the University of Pittsburgh in this regard.
  • Powder Level Simulation: R&D efforts in this space are led by Lawrence Livermore National Labs (LLNL) and the focus here is on fundamental understanding to explain observed defects and also to enable process optimization to accelerate new materials and process research

Part level simulation is of great interest for companies seeking to go down a production route with metal AM. In particular there is a need to predict part distortion and correct for it in the design – this distortion can be unacceptable in many geometries – one such example is shown in the Pan Computing (now Autodesk) video below.

A Note on Convergence

Some companies have ownership of more than one aspect of the 7 categories represented above, and are seeking to converge them either through enabling smooth handshakes or truly integrate them into one platform. In fact, Stratasys announced their GrabCAD solution at the RAPID conference, which aims to do some of this (minus the analysis aspects, and only limited to their printers at the moment – all of which are for polymers only). Companies like Autodesk, Dassault Systemes and ANSYS have many elements of the 7 software solutions listed above and while it is not clear what level of convergence they have in mind, all have recognized the potential for a solution that can address the AM design community’s needs. Autodesk for example, has in the past 2 years acquired Within (for lattice generation), netfabb (for build preparation) and Pan Computing (for simulation), to go with their existing design suite.

Conclusion: So what do I need again?

What you need depends primarily on what you are using AM technologies for. I recommend the following approach:

  • Identify which of the 4 main categories apply to you
  • Enumerate existing capabilities: This is a simple task of listing the software you have access to already that have capabilities described in the sub-categories
  • Assess gaps in software relative to meeting requirements
  • Develop an efficient road-map to get there: be aware that some software only make sense (or are available) for certain processes

In the end, one of the things AM enables is design freedom, and to quote the novelist Toni Morrison: Freedom is not having no responsibilities; it is choosing the ones you want.”  AT PADT, we work with design and analysis software as well as AM machines on a daily basis and would love to discuss choosing the appropriate software solutions for your needs in greater detail. Send us a note at info@padtinc.com and cite this blog post, or contact me directly on LinkedIn. .

Thank you for reading!

3D Printed Molds Save Time and Money for Specialty Lighting Company

Western Technology is a manufacturer of specialty lighting solutions that cater to a variety of highly specialized industries such as aviation, oil and gas, and maritime.  Their products are used in a variety of environments making it important that the design is both versatile and functional.

In their Utah office, they have been successfully utilizing a Stratasys PolyJet 3D Printer to create polyurethane molds.  By using 3D printed molds, they have been able to save both time and money over traditional manufacturing methods.

Western Technology’s 3D Printed Toggle Mold

 “Below is a pictorial of how we’ve used our new 3D printer to develop and create polyurethane parts. The parts we are producing in this mold are used to trigger a magnetic sensor inside a sealed aluminum box. Each part has a magnet and aluminum insert cast inside.” Lyal Christensen at Western Technology

The mold was printed using a Stratasys Objet 500 Connex 1 printer in a Vero Blue material (standard plastic).  This is the final result after support material has been removed.

WT1

The mold is comprised of two halves that each have 3 different parts to create this Polyurethane mold.  Below one side is shown in an un-assembled view.

WT2

Steel pins are press fit into the 3D printed part with ease to help with locating the magnets in the correct location.  Also you can see that the part has a gloss finish to it.  The parts were printed in the glossy mode which helps in minimizing the amount of support material needed to print the parts.

WT3

Inserts and Magnets are added to the mold along with a Urethane mold release agent.  The Aluminum inserts are held in the right place by screws that keep the inserts suspended so that the Urethane can engulf all sides of it.

WT4

The clamped mold then has the Urethane fed into it which is poured at room temperature.  Once all of the cavities are filled, the mold is left to cure at room temperature for just under one hour.  Using this technique, they are able to complete 6 or 7 sets per day.

WT5

The following morning the screws and the insert bridge are removed.

WT6

The mold is pried apart using a flathead screwdriver at specific cutout locations that were printed into the mold.  With a simple turn of the wrist, this mold is easily separated.

WT7

There is a little bit of flash which can easily be removed.  These parts are almost ready for the customer.

WT8

The parts are cut away and are ready for de-flashing and finishing.

WT9

At Western Technology, Lyal estimates this mold would have cost $2,000+ to manufacture in just man hours.  They were able to get 400+ parts out of this mold and are still using it.

If you would like to learn more about how to implement 3D Printing into your processes to save time and money, contact us at sales@padtinc.com.

Simulation Driven Product Development with Free Form Fabrication

am-topo-prezo-titleJoining Two of PADT’s Favorite Things: Simulation and 3D Printing

Recent advances in Additive Manufacturing (3D Printing) have removed barriers to manufacturing certain geometry because of constraints in traditional manufacturing methods. Although you can make almost any shape, how do you figure out what shape to make. Using ANSYS products you can apply topological optimization to come up with a free-form shape that best meets your needs, and that can be made with Additive Manufacturing.

A few months ago we presented some background information on how to drive the design of this type of part using ANSYS tools to a few of our customers.  It was a well received so we cleaned it up a bit (no guarantee there all the typos are gone) and recorded the presentation.  Here it is on YouTube

Let us know what you think and if you have any questions or comments, please contact us.

Selective Laser Sintering (SLS) Additive Manufacturing Service is Back on Line at PADT

sls-sinterstation-padt-2Everyone needs a vacation. After over 15 years of service our Sinterstation 2500Plus needed some facility upgrades  and machine updates. That work is now done and our SLS system is back up and running and better than ever, producing parts for customers who have come to count on its unique capabilities.

sls-housing-bracket-1Selective Laser Sintering (SLS) is a process that uses a high power laser to fuse a bed of powdered material together, sintering the loose powder into solid geometry. It is one of the more mature and robust 3D Printing processes available and is especially well suited for making large strong parts.

We currently run Nylon 11 and Glass Filled Nylon 12 in our machine which has a build volume of 13″ x 11″ x 16.5″ and a layer thickness of 0.004″

sls-sinterstation-cleaning-padt-1Few service providers have as much experience as PADT with this system, we have been using it for over 15 years. During that time we have upgraded almost every component and during the recent downtime, the system was fully calibrated and tuned for maximum precision and performance. We are also experts on how to post process the parts that come out of this machine, including painting and other coatings.

Just a Part of 3D Printing at PADT

PADT features 3D Printing services using Stratasys FDM and PolyJet technologies, making precision parts with a wide variety of materials and colors. We also offer Stereolithography (SLA) Additive Manufacturing services along with soft tooling and injection molding consulting.

 

Demo-Room-Pic-1If you are using a big impersonal 3D Printing “mill” or are not sure where to get your 3D Printing done, reach out to PADT. We have been doing it since 1994 and have hundreds of happy and loyal customers.

email: rp@padtinc.com

call: 480.813.4884

or visit our Rapid Prototyping Services pages at:

www.padtinc/com/rp

sls-gear-box-1

Unexpected Joys at Rapid 2016

While much has been (justifiably) written about HP and XJet releasing new, potentially game-changing products at RAPID 2016, I wanted to write this post about some of the smaller, unexpected joys that I discovered. If I sound overly enthusiastic about the people and companies behind them, it is likely due to the fact that I wrote this on the flight back, staring out at the clouds and reflecting on what had been a wonderful trip: I own no locks, stocks or barrels in any of these companies.

1. Essentium Materials – Carbon Nanotubes and Microwaves to improve FDM mechanical properties
Over the past year, I have studied, written and made presentations about the challenges of developing models for describing Fused Deposition Modeling (FDM) given their complex and part-specific meso-structure. And while I worked on developing analytical and numerical techniques for extracting the best performance from parts in the presence of significant anisotropy, the team at Essentium has developed a process to coat FDM filaments with Carbon nanotubes and extrude them in the presence of microwave radiation. In the limited data they showed for test specimens constructed of unidirectional tool-paths, they demonstrated significant reduction in anisotropy and increase in strength for PLA. What I liked most about their work is how they are developing  this solution on a foundation of understanding the contributions of both the meso-structure and inter-filament strength to overall part performance. Essentium was awarded the “RAPID Innovations award”, first among the 27 exhibitors that competed and are, in my opinion, addressing an important problem that is holding back greater expansion of FDM as a process in the production space.
Website: http://essentiummaterials.com/

2. Hyrel 3D – Maker meets Researcher meets The-Kid-in-All-of-Us
I only heard of Hyrel 3D a few days prior to RAPID, but neglected to verify if they were exhibiting at RAPID and was pleasantly surprised to see them there. Consider the options this 3D printer has that you would be hard pressed to find in several 3D printers combined: variable extrusion head temperatures (room temp to 450 C), sterile head options for biological materials, a 6W laser (yes, a laser), spindle tools, quad head dispensing with individual flow control and UV crosslinking options. Read that again slowly. This is true multiple degree-of-freedom material manipulation. What makes their products even more compelling is the direct involvement of the team and the community they are building up over time, particularly in academia, across the world, and the passion with which they engage their technology and its users.
Website: http://www.hyrel3d.com/

3. Technic-Print: New Chemistry for Improved FDM Support Removal
If you manufacture FDM parts with soluble supports, keep reading. A chemist at Technic Inc. has developed a new solution that is claimed to be 400% faster than the current Sodium-Hydroxide solution we use to dissolve parts. Additionally, the solution is cited as being cleaner on the tank, leaving no residue, has a color indicator that changes the solution’s color from blue to clear. And finally, through an additional agent, the dissolved support material can be reclaimed as a clump and removed from the solution, leaving behind a solution that has a pH less than 9. Since PADT manufactures one of the most popular machines that are used to dissolve these supports that unbeknown to us, were used in the testing and development of the new solution, we had an enriching conversation with the lead chemist behind the solution. I was left wondering about the fundamental chemistry behind color changing, dissolution rates for supports and the reclaiming of support – and how these different features were optimized together to develop a usable end-solution.
Website: http://www.technic.com/techni-print-lp

 

4. Project Pan: Computationally Efficient Metal Powder Bed Fusion Simulation
I presented a literature review at AMUG (another Additive Manufacturing conference) last month, on the simulation of the laser-based powder bed fusion. At the time, I thought I had captured all the key players between the work being done at Lawrence Livermore National Labs by Wayne King’s group, the work of Brent Stucker at 3DSIM and the many academics using mostly commercially available software (mostly ANSYS) to simulate this problem. I learned at RAPID that I had neglected to include a company called “Project Pan” in my review. This team emerged from Prof. Pan Michaleris’s academic work. In 2012, he started a company that was acquired by Autodesk two months ago. In a series of 3 presentations at RAPID, Pan’s team demonstrated their simulation techniques (at a very high level) along with experimental validation work they had done with GE, Honeywell and others through America Makes and other efforts. What was most impressive about their work was both the speed of their computations and the fact that this team actually had complex part experimental validations to back up their simulation work. What most users of the powder bed fusion need is information on temperatures, stresses and distortion – and within time frames of a few hours ideally. It seems to me that Pan and his team took an approach that delivers exactly that information and little else using different numerical methods listed on their site (novel Hex8 elements, an element activation method and intelligent mesh refinement) that were likely developed by Pan over the years in his academic career and found the perfect application, first in welding simulation and then in the powder bed fusion process. With the recent Autodesk acquisition, it will be interesting to see how this rolls out commercially. Details of some of the numerical techniques used in the code can be found at their website, along with a list of related publications.

Website: http://pancomputing.com/

5. FDA Participation: Regulating through education and partnership
On a different note from the above, I was pleasantly surprised by the presence of the FDA, represented by Matthew Di Prima, PhD. He taught part of a workshop I attended on the first day, took the time to talk to everyone who had an interest and also gave a talk of his own in the conference sessions, describing the details of the recently released draft guidance from the FDA on 3D printing in medical applications. It was good to connect the regulatory agency to a person who clearly has the passion, knowledge, intelligence and commitment to make a difference in the Additive Manufacturing medical community. Yes, the barriers to entry in this space are high (ISO certifications, QSR systems, 510(k) & Pre-Market Approvals) but it seems clear that the FDA, at least as represented by Dr. Di Prima, are doing their best to be a transparent and willing partner.
Website: http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/3DPrintingofMedicalDevices/default.htm

What really makes a trip to a conference like RAPID worth it are the new ideas, connections and possibilities you come away with that you may not stumble upon during your day job – and on that account, RAPID 2016 did not disappoint. As a line in one of my favorite song’s goes:

“We’ll never know, unless we grow.
There’s too much world outside the door.”
– Fran Healy (Travis, “Turn”).

PADT and ASU Collaborate on 3D Printed Lattice Research

The ASU Capstone team (left to right): Drew Gibson, Jacob Gerbasi, John Reeher, Matthew Finfrock, Deep Patel and Joseph Van Soest.
ASU student team (left to right): Drew Gibson, Jacob Gerbasi, John Reeher, Matthew Finfrock, Deep Patel and Joseph Van Soest

Over the past two academic semesters (2015/16), I had the opportunity to work closely with six senior-year undergraduate engineering students from the Arizona State University (ASU), as their industry adviser on an eProject (similar to a Capstone or Senior Design project). The area we wanted to explore with the students was in 3D printed lattice structures, and more specifically, address the material modeling aspects of these structures. PADT provided access to our 3D printing equipment and materials, ASU to their mechanical testing and characterization facilities and we both used ANSYS for simulation, as well as a weekly meeting with a whiteboard to discuss our ideas.

While there are several efforts ongoing in developing design and optimization software for lattice structures, there has been little progress in developing a robust, validated material model that accurately describes how these structures behave – this is what our eProject set out to do. The complex internal meso- and microstructure of these structures makes them particularly sensitive to process variables such as build orientation, layer thickness, deposition or fusion width etc., none of which are accounted for in models for lattice structures available today. As a result, the use of published values for bulk materials are not accurately predictive of true lattice structure behavior.

In this work, we combined analytical, experimental and numerical techniques to extract and validate material parameters that describe mechanical response of lattice structures. We demonstrated our approach on regular honeycomb structures of ULTEM-9085 material, made with the Fused Deposition Modeling (FDM) process. Our results showed that we were able to predict low strain responses within 5-10% error, compared to 40-60% error with the use of bulk properties.

This work is to be presented in full at the upcoming RAPID conference on May 18, 2016 (details at this link) and has also been accepted for full length paper submission to the SFF Symposium. We are also submitting a research proposal that builds on this work and extends it into more complex geometries, metals and failure modeling. If you are interested in the findings of this work and/or would like to collaborate, please meet us at RAPID or send us an email (info@padtinc.com).

Our final poster and the Fortus 400mc that we printed all our honeycomb structures with
The final poster summarizing our work rests atop the Stratasys Fortus 400mc that we printed all our honeycomb structures on

Technology Trends in Laser-based Metal Additive Manufacturing

amug-2
Figure 1. Concept Laser’s M2 Cusing at AMUG 2016

One of the more difficult things about being at the Additive Manufacturing Users Group (AMUG) is dealing with the fact that there is more to do than you can hope to accomplish in four and a half days. So I decided to focus on two themes: laser-based metal additive manufacturing (AM); and design & simulation for AM. In this post, I focus on the former and try to distill the trends I noticed across the laser-based metal AM system manufacturers that were present at the conference: Concept Laser, SLM, Renishaw, EOS and 3D Systems (listed here in the decreasing order of the time I spent at each supplier’s booth). While it is interesting to study how 5 different suppliers interpret the same technology and develop machines around it, it is not my objective to compare them here, but to extract common trends that most suppliers seem to be working on to push their machines to the next level. For the purposes of this post, I have picked the top-of-the-line machine that each supplier offers as an indication of the technology’s capabilities: they span a range of price points, so once again this is not meant to be a comparison.

As a point of observation, the 5 key trends I noticed turned out to be all really aspects of taking the technology from short run builds towards continuous production. This was not my intent, so I believe it is an accurate indication of what suppliers are prioritizing at this stage of the technology’s growth and see as providing key levers for differentiation.

1. Quality Monitoring

Most customers of AM machines that wish to use it for functional part production bemoan the lack of controls during manufacturing that allow them to assess the quality of a part and screen for excursionary behavior without requiring expensive post-processing inspection. Third party companies like Sigma Labs and  Stratonics have developed platform-independent solutions that can be integrated with most metal AM systems. Metal AM suppliers themselves have developed a range of in-situ monitors that were discussed in a few presentations during AMUG, and they generally fall into the following categories:

  • Input Monitors:
    • Laser: Sensors monitor laser powder as well as temperature across the different critical components in the system
    • Oxygen Level: Sensors in the build chamber as well as in sieving stations track O2 levels to ensure the flushing of air with inert Argon or Nitrogen has been effective and that there are no leaks in the system
  • Output Monitors:
    • Live video: simple but useful, this allows users to get a live video stream of the top layer as it is being built and can help detection of recoater blade damage and part interaction
    • Meltpool: Concept Laser showed how its Meltpool monitoring system can be used to develop 2D and 3D plots that can be superimposed with the 3D CAD file to identify problematic areas – the video is also on YouTube and embedded below. SLM and EOS offer similar meltpool monitoring solutions.
    • Coater consistency: Concept Laser also described a monitor that captures before and after pictures to assess the consistency of the coater thickness across the build area – and this information is fed forward to adjust subsequent coater thicknesses in an intelligent manner.

Quality monitoring systems are still in their infancy with regard to what is done with the information generated, either in terms of feed forward (active) process control or even having high confidence in using the data to validate part quality. A combination of supplier development and academic and industry R&D is ongoing to get us to the next level.

2. Powder Handling

In a previous post, I touched upon the fire and explosion risks posed by metal powder handling. To lower the bar for an operator to gain access to a metal AM machine, one of the considerations is operator safety and the associated training they would need. Suppliers are constantly trying to improve the methods by which they can minimize powder handling. For a mechanical engineer, it is intriguing to see how reactive metal powders can be moved around in inert atmospheres using different strategies. The SLM 500HL uses a screw system to move the powder around in narrow tubes that stick out of the machine and direct the material to a sieving station after which they are returned to the feed area. The Renishaw RenAM 500M on the other hand uses a pneumatically driven recirculation system powered by Argon gas that is well integrated into the machine frame. Concept Laser also offers automated powder handling on the XLine 2000R, while EOS and 3DSystems do not offer this at the moment. Figure 2 below does not do justice to the level of complexity and thought that needs to go into this.

Figure 2. Two different automated powder handling systems in use in metal AM machines

One of the limitations of automating powder handling is the ability to change materials, which is very hard to impossible to do with high enough confidence with these systems. As a result, their use is limited to cases where one machine can be dedicated to one material and efficiency gains of powder handling can be fully realized. The jury is still out on the long term performance of these systems, and I suspect this is one area that will continue to see improvements and refinements in subsequent model releases.

3. Multi-Laser Processing

In the quest for productivity improvement, one of the biggest gains comes from increasing the number and power of available lasers for manufacturing. In my previous experience with laser based systems (albeit not for this application), an additional laser can increase overall machine throughput by 50-80% (it does not double due to steps like the recoater blade movement that does not scale with the number of lasers).

The suppliers I visited at AMUG have very different approaches to this: SLM provides the widest range of customizable options for laser selection with their 500HL, which can accept either 2 or 4 lasers with power selection choices of 400W or 1000W (the 4 laser option was on display, YouTube video from the same machine in action is below) – the lasers of different powers can also be combined to have two 400W and two 1000W lasers. Concept Laser’s XLine 2000R allows for either 1 or 2 1000W lasers and their smaller, M2 machine that was showcased at AMUG has options for 1 or 2 lasers, with power selection of 200W or 400W. EOS, Renishaw and 3D Systems presently offer only single laser solutions: the EOS M 400 has one 1000W laser, Renishaw’s RenAM 500M has one 500W laser and the ProX DMP 320 from 3D Systems has one 500W laser.

There are a few considerations to be aware of when assessing a multi-laser machine: Each laser drives an increase in machine capital cost. But there is another point of note to remember when using multi-laser systems for manufacturing that centers around matching process outputs from different lasers: laser-to-laser variation can be a dominant source of overall process variation and can drive a need to calibrate, maintain and control both lasers as if they were independent machine systems. Additionally, development of  a process on one particular laser power (100W, 400W, 500W, 1000W) may not scale easily to another and is something to remember when developing a long term strategy for metal AM that involves different kinds of machines, even if from the same supplier.

4. Software Integration

Renishaw spent a significant amount of time talking about their easy-to-use QuantAM software which is designed to integrate Renishaw process parameters and part processing information more tightly and allow for seamless process parameter development without needing third part software like Magics. Additive Industries announced in their presentation at AMUG that they had just signed an agreement with 3DSIM to integrate their support design software solution into their MetalFab1 machine. Software integration is likely to be an increasing trend especially around the following areas:

  • Improving support design methods and reducing its empirical nature and reducing the material, build time and support removal costs associated with them as well as eliminating the need for iterative builds
  • Increasing process options available to the user (for example for the outer skin vs the inner core, or for thick vs thin walls)
  • Simplifying the development of optimized process parameters for the user working on new materials
  • Integrating design and process optimization to increase effective part performance

In a future blog post, I will look specifically at the many design and simulation tools available around AM and how they are connected today even if not well-synergized.

5. Modular System Architectures

In a list of mostly evolutionary changes, this is the one area that struck me as being a step-change in how this technology will make an impact, even if it will be felt only by larger scale manufacturers. Concept Laser and Additive Industries are two companies that delivered presentations discussing how they were approaching the challenge of revolutionizing the technology for true production and minimizing the need for human touch. Common to both is the notion of modularity, allowing for stacking of printing, powder removal, heat treating and other stations. While Additive Industries are developing a flow resembling a series production line, Concept Laser have taken the more radical approach of having autonomous vehicles delivering the powder bed to the different stations, with travel channels for the vehicles, for the operator and for maintenance access (Figure 3). Both companies expect to have solutions out by the end of this year.

Figure 3. Concept Laser’s “Factory of Tomorrow” features swim-lanes for operators and for autonomous vehicles that will deliver powder and parts from one module to another

Concluding Thoughts

It is an interesting time to be a manufacturer of laser-based metal 3D printers, and an even more interesting time to be a consumer of this technology. The laser-material interaction fundamentals of the process are now fairly well-established. Competitors abound both in existing and emerging markets with machines that share many of the same capabilities. Alternative technologies (E-Beam melting, deposition and jetting) are making strides and may start to play in some applications currently dominated by laser-based technologies. A post early-adopter chasm may be around the corner. This will continuously drive the intense need to innovate and differentiate, and possibly also lead to a merger or two. And while most of the news coming out of conferences is justifiably centered around new process technologies (as was the case with Carbon’s CLIP and XJET’s metal nanoparticle jetting at AMUG this year), I think there is an interesting story developing in laser-based powder bed fusion and can’t wait to see what AMUG 2017 looks like!

Press Release: 3D Printing Expertise from PADT Advances Aerospace Industry

ula-rocket-duct-made-from-3d-printed-partsMany of you may have seen the recent launch of an Atlas V rocket from United Launch Alliance (ULA).  We are honored to have lent our expertise to ULA’s 3D Printing efforts that resulted in the use of parts on that rocket made with additive manufacturing.   We will be talking about that and other ways we help the Aerospace Industry at the 32nd Space Symposium this week in Colorado Springs Colorado.  Please stop by!

Read more in the press release.  A PDF can be found here.

Press Release:

3D Printing Expertise from PADT Advances Aerospace Industry

Product design and development leader provides additive manufacturing support for United Launch Alliance Atlas V rocket

COLORADO SPRINGS, Colo.April 11, 2016PRLog — Phoenix Analysis & Design Technologies Inc. (PADT), the Southwest’s largest provider of Numerical Simulation, Product Development, and 3D Printing services and products, is highlighting its expertise this week at the 32nd Space Symposium,  the premier global, commercial, civil, military and emergent space conference.

During the symposium, PADT experts in additive manufacturing will be on hand to discuss the company’s technical expertise, logistics, sales and service capabilities in the exciting aerospace sector, which contributed to the successful launch on March 22 of a United Launch Alliance (ULA) Atlas V rocket. The Atlas V rocket made use of lightweight thermoplastic 3D printed parts, with the application of Stratasys technology supplied by PADT and consulting from PADT on how best to apply that technology to engineering, tooling, and production.

Stop by and visit PADT’s booth 1310 at the 32nd Space Symposium, April 11-14, in Colorado Springs, Colorado. http://www.spacesymposium.org/.

“PADT continues to be both a great supplier of both polymer and metal additive manufacturing technologies and an additive manufacturing technical consultant to ULA, supporting our Atlas V, Delta IV and future Vulcan Centaur launch vehicles,” said Greg Arend, ULA manager, Additive Manufacturing. “By consulting with PADT, we were able to understand how these technologies enhance our design and manufacturing process, saving time, money and weight. PADT’s knowledge of the use of both polymer and metal materials was instrumental in helping us achieve our success.”

In addition to supplying ULA with Stratasys’ polymer 3D Printing machines, PADT consulted with them early on andled a tour of Oakridge National Labs to help them understand the state of the art for both metal and polymer applications and produced a technological roadmap for both technologies that has largely been followed.  Assisted by PADT, both companies made use of additive manufacturing for engineering prototypes, then advanced to the production of tooling for manufacturing and developed the confidence needed to move to flight hardware.

The founders of PADT have been involved with additive manufacturing since the late 1980’s and the company was the first service provider in the Southwest in 1994.  Over the years, PADT has built a reputation for technical excellence and a deep understanding of how to apply various 3D printing technologies to enable real world applications.  Their sales team has shown the ability to sell sophisticated engineering products to companies large and small, and to provide excellent support to their customers.

“3D Printing is not just about makers, nor is it just about engineering prototypes,” said Rey Chu, co-owner, principal and director of Manufacturing Technologies at PADT. “Every day users are creating production hardware to produce usable parts that save them time and money. Ducts for rockets are a perfect application of 3D printed parts because they are complex, low volume, and can make single parts that need to be made in multiple pieces using traditional methods.”

About Phoenix Analysis and Design Technologies

Phoenix Analysis and Design Technologies, Inc. (PADT) is an engineering product and services company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and Rapid Prototyping solutions. PADT’s worldwide reputation for technical excellence and experienced staff is based on its proven record of building long term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.” With over 80 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, and from offices in Torrance, California, Littleton, Colorado, Albuquerque, New Mexico, and Murray, Utah, as well as through staff members located around the country. More information on PADT can be found at http://www.PADTINC.com

— End —

 

Reactive and Non-Reactive Metal Alloys in Laser-based Powder Bed Fusion

One of the first concepts you come across in metal 3D printing is the notion of reactivity of the powder metal alloys – in this post, I investigate why some of these powder alloys are classified as reactive and others as non-reactive, and briefly touch upon the implications of this to the user of metal 3D printing tools, scoping the discussion to laser-based powder bed fusion. Ultimately, this boils down to a safety issue and I believe it is important that we, the users of these technologies, truly understand the fundamentals behind the measures we are trained to follow. If you are looking to get something chemical etched visit https://interplex.com/technology/process-capability/chemical-etching/.

Figure 1 below is indicative of the range of materials available currently for the laser-based powder bed fusion process (this selection is from Concept Laser). I have separated these into non-reactive and reactive metal alloys. The former includes steels, Inconels, bronze and CoCrW alloys. The reactive metal alloys on the other hand are Aluminum or Titanium based. The question is: what classifies them as such in the context of this process?

Figure 1.
Figure 1. Typical metal alloys available for the laser-based powder bed fusion process (from Concept Laser), classified as Non-Reactive and Reactive

Reactivity in this process really pertains to the likelihood of the alloy in question serving as a fuel for a fire and/or an explosion, which are two related but distinct phenomena. To truly understand the risk associated with powder metals, we must first understand a few basic concepts.

1. Fire and Explosion Criteria

Figure 2 is a commonly used representation of the criteria that need to be met to initiate a fire (fuel, oxygen and an ignition source) and an explosion (the same three criteria for a fire, plus a dust cloud and confined space). When handling reactive metal alloy powders, it is important to remember that two of the three requirements for a fire are almost always met and the key lies in avoiding the other criterion. When not processing the powder in the machine, it is often subject to ambient oxygen content and thus all precautions are taken to prevent an ignition source (an ESD spark, for example). When the metal is being processed with a high power laser, it is done in an inert atmosphere at very low Oxygen levels. This thought process of appreciating you are one criterion away from a fire is useful, if sobering, to bear in mind when working with these powders.

fireexplosion
Figure 2. The fire triangle and explosion pentagon

2. Terms Used to Describe Fire and Explosion Risk

There are several terms used to describe fire and explosion risk. I have picked 5 here that tie into the overall “index” I will discuss in the following section. All these parameters are in turn functions of the material in question, both with regard to its composition and its size distribution and are co-dependent. These definitions are adapted from Benson (2012) and Prodan et al. (2012).

  • Fire Related: These two terms describe the sensitivity of a metal dust cloud to ignition.
    • Ignition Temperature: This is the lowest surface temperature capable of igniting a powder or dust dispersed in the form of a dust cloud
    • Minimum Ignition Energy: This measures the ease of ignition of a dust cloud by electrical and electrostatic discharges.
  • Explosion Related: These terms describe the severity of an explosion arising from a fire once ignited.
    • Minimum Explosion Concentration (MEC): This is the smallest amount of dust which when suspended in air, under a set of test conditions, will initiate an explosion and propagate even after the action of the ignition source has ceased.
    • Maximum Explosion Pressure: This is a measure of the highest pressure that occurs during of an explosion of a flammable mixture in a closed vessel.
    • Maximum Rate of Pressure Rise: This is the maximum slope of the pressure/time curve during a flammable mixture explosion in a closed vessel.

3. Index of Explosibility

Having defined these terms, the question is how they can be tied together to give some sense of the hazard associated with each metal powder. I came across a 1964 US Bureau of Mines study that defined an Index of Explosibility as a measure of the hazard risk posed by powder metal alloys. The index represents both the sensitivity of the powder to ignition, and once ignited, the severity of the resulting explosion. Since this is a subjective metric, it is normalized by comparison against a “standard”, which was selected as Pittsburgh coal dust in the 1964 study. Importantly though, this normalization enables us to do qualitative comparisons between metal powders and have some sense of the hazard risk posed by them. Figure 3 is the equation reproduced from the original 1964 report and shows how this term is estimated.

Index of Explosibility (US Bureau of Mines study, 1964)
Figure 3. Index of Explosibility (US Bureau of Mines study, 1964)
Figure 3. Particle size has a significant impact on explosibility
Figure 4. Particle size has a significant impact on explosibility

The study also showed how the index was a direct function of particle size. Most powders for 3D metal printing are in the 20-100um range, and as shown in Fig. 4 for atomized Aluminum, the risk of an explosion increases with reducing particle diameter. 

The authors tested a range of metals and computed the different variables, which I have compiled anew in the table in Figure 5 for the ones we are interested in for metal 3D printing. The particle sizes in the 1964 study were ones that made it through a No. 200 sieve (less than 75 microns), but did not include sub-micron particles – this makes it an appropriate comparison for metal 3D printing. It is clear from the Index of Explosibility values, as well as the Cloud Ignition Temperatures in the table below why Aluminum and Titanium are classified as reactive metals requiring special attention and care.

Figure . Explosibility study findings from US Bureau of Mines study (1964)
Figure 5. Index of Explosibility comparison for selected metal alloys, adapted from US Bureau of Mines study (1964)

4. Implications for Metal 3D Printing

So what does this mean for metal 3D printing? There are three things to be aware of that are influenced by whether you are working with non-reactive or reactive alloys – I only provide a general discussion here, specific instructions will be provided to you in supplier training and manuals and must be followed.

  • Personal Protective Equipment (PPE): There are typically two levels of PPE: standard and extended. The standard PPE can be used for non-reactive alloy handling, but the reactive alloys require the more stringent, extended PPE. The main difference is that the extended PPE requires the use of a full bunny suit, ESD grounding straps and thermal gloves.
  • Need for Inert Gas Handling: Many tasks on a metal 3D printer require handling of powder (pouring the powder into the chamber, excavating a part, cleaning the chamber of powder etc.). Most of these tasks can be performed in the ambient for non-reactive metal alloys with standard PPE, but for reactive alloys these tasks must be performed in an inert atmosphere.
  • Local authority approvals: It is important that your local authorities including the fire marshall, are aware of the materials you are processing and review and authorize their use in your facility before you turn on the machine. Local regulations may require special procedures be implemented for preparing the room for use of reactive metal alloys, that do not apply to non-reactive metals. It is vital that the authorities are brought into the discussion early on and necessary certifications obtained, keeping in mind that reactive metal alloy use may drive additional investment in safety measures.

5. Conclusion

Safe operation of metal 3D printers requires installation of all the necessary safety equipment, extensive hands-on training and the use of checklists as memory aides. In addition to that, it helps to connect these to the fundamental reasons why these steps are important so as to gain a clearer appreciation of the source of the hazard and the nature of the risk it poses. In this article I have tried to demonstrate why reactivity in metal 3D printing matters and what the basis is for the classification of these metal alloys into reactive and non-reactive by leveraging an old 1964 study. I wish to close with a reminder that this information is meant to supplement formal training from your equipment supplier – if there is any conflict in the information presented here, please revert to your supplier’s recommendations.

Thank you for reading; stay safe as you innovate!

Additive Manufacturing and the Navy SBIR Program – brought to you by RevAZ, AZ Commerce Authority, and PADT

RevAZ-ACA-PADT-Logos-1

Learn more about the Navy Sea SBIR Program from Jonathan Leggett, the NAVSEA SBIR Program Manager, about how AZ Manufacturers can use SBIR Grants to assist in funding R&D early stage innovation.  Jonathan will also review the Navy’s roadmap on additive manufacturing and 3D printing.  There will be 15 minute one-on-one sessions from 1:30 – 4:00 to answer your specific questions with:

  • Jonathan Leggett, NAVSEA SBIR Outreach Program Manager
  • Dave Garafano, ACA Executive Director of RevAZ
  • Jill HowardAllen, ACA Manger of Technology Commercialization & SBIR Programming

Register Now!

Who Should Attend?

  • Small to Medium Sized Businesses – (500 or less)manufacturers interested in learning how the SBIR/STTR program may assist them in commercializing their early stage innovation.
  • Large & Medium Sized Businesses and/or 3rd Party Investors – Those seeking to partners with the SBIR/STTR small businesses to (a) establish the requirements and specification for the proposed outcomes; and (b) provide financial resources and collaboration for commercializing the results
  • University/Institute Faculty and Staff – Those seeking consulting and partnering opportunities with the small business on the SBIR/STTR grant

When: April 7
10:00-12:00 – Navy SBIR Overview & Navy
Additive Manufacturing Technology Roadmap
1:30- 4:00 – 15 Minute 1:1 Sessions with Jonathan Leggett

Where: PADT
7755 S Research Dr.
Suite 120
Tempe, AZ 85284

Please Register to Reserve your Spot!

Direct any questions to Jill HowardAllen at JillH@azcommerce.com or call 602 845 1291.

PADT is honored to be hosting the event and taking part in the training.

Ovid: A Teaching Tool for 3D Printing

ovid-1-1Meet Ovid.  He is a very simple character that we use to explain 3D Printing to kids. Explaining how 3D Printing works to anyone without a technical background can be tough. To help out PADT has created a collection of resources that shows how it is done, including a hands on model for younger kids, that feature Ovid as the object being printed.

Let’s start by getting technical.  3D Printing is a common term for a class of manufacturing methods referred to as Additive Manufacturing.  In 3D Printing you take a computer model and you print it out to get a real world three dimensional object. The way we do it is that we slice the computer model into thin layers, then build up material in the 3D printer one layer at a time.  Here is a simple GIF showing the most common process:

FDM-Animation.gif

This is Fused Deposition Modeling, or FDM. If a classroom has a 3D Printer it is most likely an FDM printer.

The idea behind these resources is to show the process:

  1. Start with a 3D Computer model
  2. Slice it
  3. Build it one layer at a time

The materials below can be used by parents or teachers to explain things to kids, K-8. Please use freely and share!

Presentation

This PowerPoint has slides that explain the 3D Printing process and the video is of the slides being presented, with our narration.

PowerPoint: Ovid-Presentation-3D_Printing

Making a Hands-On Ovid

ovid-model-3Our fun little plexiglass model of Ovid is an example of a manual 3D printing process. Students can stack up the layers to “3D Print” their own Ovid by hand, reinforcing the layered manufacturing process.

We did everything the same as a real 3D Printer, but instead of automatically stacking the layers, we cut each layer on a laser cutter and the students do the cutting.

Here is a video showing the laser cutting.

And this is a zip file containing the geometry we used to make Ovid in STEP, IGES, Parasolid, and SAT.

To put it all together we created a triangular rod with a base and height that are identical.  Figure out the size you need once you have scaled the geometry for your version of Ovid. we glued the rod to a base.

ovid-model-1 ovid-model-4 ovid-model-2

Files for 3D Printing and Other Information

If you have access to a 3D Printer, you can print your own Ovid.  Here is an STL and a Parasolid: Ovid-PADT-3D_Printing-1

We also have a video showing how the software for the printer slices the geometry and makes the tool path for each layer:

And to round things out, here is a few minutes of Ovid being made in one of our Stratasys FDM printers:

MD+DI: 3-D Printing Applications Changing Healthcare

md+di-logo-13-D Printing is having a significant impact on healthcare technology. In “3-D Printing Applications Changing Healthcare” PADT’s Dhruv Bhate gives real world examples of how this technology is enabling never-before-seen breakthroughs.

 

Support Design and Removal for 3D Printed ULTEM-9085 (Case Study: Intake Manifold)

ULTEM-9085 is one of my favorite materials to 3D-print: one of the reasons is it is a high performance polymer that can and has been used for end part manufacturing (see my blog post about ULTEM in functional aerospace parts), but the other is because it is a demanding material to print, in ways that ABS, Polycarbonate and even Nylon are not. What makes it demanding is primarily that ULTEM supports are not soluble and need to be removed mechanically. An additional challenge comes from the fact that the support is best removed when the part is at a high temperature (175-195 C), which requires the use of gloves and reduces the user’s dexterity. For complex geometries with internal channels, this is particularly challenging and occasionally results in an inability to print a certain part in ULTEM-9085, which runs contrary to the design freedom this technology otherwise enables.

In this post, I accumulate what I have learned through working (and failing) on many an ULTEM-9085 job, as well as through discussions with other users, and share this here in terms of design and process guidelines. To demonstrate these guidelines, I use a recent geometry that we printed for the Arizona State University’s (ASU) SAE team for an engine intake manifold. These guidelines apply to the Stratasys Fortus platform (for Fused Deposition Modeling, or FDM) using the Insight software that accompanies these tools. The screen shots are from Insight 10.6, and a Fortus 400 was used to print the parts shown.

Summary of Guidelines:

  1. Orient the part to eliminate supports in regions where you cannot remove them
  2. Use the box support style
  3. Optimize parameter settings (support angle, contour width, layer thickness)
  4. Remove the supports as soon as the part comes out of the build chamber
  5. Other observations: the interface of separation

1. Part Orientation

The single most important factor in simplifying support removal is part orientation. Most users of the FDM process know that part orientation determines the amount of support material consumed and also impacts the time to build the part. When working with ULTEM-9085, the additional challenge is that it is possible to design in supports that cannot be removed and will require you to scrap the job. This is especially true of internal features. While the automatic orientation feature in Insight allows you to minimize supports, it does not account for the difficulty of removing them. Thus when you are dealing with internal features, you may need to manually orient your part such that the internal features are aligned as close to the vertical as possible, and above the support angle (to be covered later).

As shown in Figure 1, for the intake manifold, I oriented the internal pipe structure close to the vertical and had to iterate a few times and verify that I had no support in the hard-to-reach areas. While I did have supports internally, they were limited to areas that were easy to access.

Figure 1. Engine intake manifold, to be printed out of ULTEM-9085
Figure 1. Engine intake manifold, to be printed out of ULTEM-9085
Figure 2. Part orientation to avoid any internal supports
Figure 2. Part orientation to avoid any internal supports in inaccessible regions

2. Box Supports

In a recent software upgrade, Insight added the ability to create box supports. The support structures consist of adjacent boxes instead of a continuous raster, which has the effect of allowing for easier separation of the support, though does slow down the build time. In my experience this support strategy does help with removal – the one parameter to consider here is the “Perforations” setting, though the default values were used for this part. The perforation is a layer of model material that is inserted into the support to make for easier breaking off of the support material. All cleavage surfaces in Fig. 3 are at perforation edges and you can see the building like construction with each floor distinguished by a layer of model material. When you have supports in hard to access regions, consider increasing the interval height so as to ensure you get separation at the model-support interface on the part before it occurs within the support on a perforation layer.

Figure Box Supports
Figure 3. Box Supports after removal from an ULTEM-9085 part

3. Optimize Process Parameters

While orientation will have the most significant impact on the support you need, another variable to be aware of is the “Self-Support Angle” parameter. This angle is measured from the horizontal, and represents the minimum angle of the part wall that will be built without supports. As a result, to reduce support requirements, you want this number to be as low as possible so that a greater volume of the part can be self-supported. Stratasys recommends default values, but these scale as a function of the contour width, and layer thickness, as shown in Fig. 4. The values bottom out at 40 degrees for the 0.013″ layer thickness and 43 degrees for the 0.010″ layer thickness. Thus, all other things being equal, you will be able to reduce the support needed by choosing a 0.013″ layer thickness and a 0.026″ or larger contour width. Note that both of these will impact your ability to resolve thin walls and fine features, so ensure you scan through all the tool-paths to validate that the geometry is accurately filled in.

Figure 4. Graph showing how the default values of the self-support angle vary as a function of contour width for the two layer thickness options available for ULTEM. Lower the angle, less the support needed.

4. Remove Supports Immediately

Supports are best removed when the model-support interface is hot. The best time to do this is right after you remove the parts from the print chamber, which is held at 195 C for ULTEM-9085. Ensure you have safety glasses on, work with thermal gloves and have a plier handy to pull out the support. In theory the parts can be re-heated again (175 C is a reasonable value for the oven), but Stratasys suggests that each re-heat cycle actually strengthens the interface, making it harder to remove. As a result, the best time to remove the supports is immediately out of the printer. Figure 5 shows the results of support removal for the intake manifold parts, including the build sheet.

Figure 5. Support removal can be a messy affair as you beat the clock against the cooling parts. Ensure you have gloves, a plier and safety glasses on.
Figure 5. Support removal can be a messy affair as you beat the clock against the cooling parts. Ensure you have gloves, a plier and safety glasses on.

5. Other Observations: the Interface of Separation

It helps to visualize what we are trying to do when we remove supports. There are two interfaces in question here, as shown in Figure 6. One is the model-support interface, the other is the support-box structure interface. We need separation at the model-support interface since removing the thin piece of interface material can prove challenging if the box supports have broken off (as happened for the piece below). What this means is as you remove support, you need to not just pull the supports but also add some peeling force that creates the separation. Once you create separation at the correct interface, you can pull the supports and should have proper cleavage.

Figure 6. (top) Support-model interface surface, and (bottom) support structure interface - it is important to get separation at the former interface
Figure 6. (top) Support-model interface surface, and (bottom) support structure interface – it is important to get separation at the former interface

One final point to keep in mind is that in some cases, eliminating internal supports may be impossible, as shown for a different part in Figure 7 below. The point is to eliminate the support in places you cannot reach with your pliers and get enough peeling force applied to. In the case below, I chose to have supports at the wide opening since I had adequate access to them. With practice, you will get a better sense of what supports can and cannot be removed and use that intuition to better shape your design and process layout decisions before you print.

Figure 6. Support in internal features are alright as long as you have access to them
Figure 7. Support in internal features are alright as long as you have access to them
Figure 7. The final part!
Figure 8. The final part
The ULTEM intake manifold runner and plenum being put through its paces at the ASU Formula SAE test rig
Figure 9. The ULTEM intake manifold runner along with a plenum that we also printed, both being put through their paces at the ASU Formula SAE test rig (Photo Ack: Michael Conard)

Show your support for ASU’s Formula SAE team at their Facebook page and see a video about the endeavor here.

The 3D Printing Value Proposition

At a recent Lunch-n-Learn organized by the Arizona Technology Council, I had the opportunity to speak for 10 minutes on 3D printing. I decided to focus my talk on trying to answer one question: how can I determine if 3D printing can benefit my business? In this blog post, I attempt to expand on the ideas I presented there.

While a full analysis of the Return-On-Investment would require a more rigorous and quantitative approach, I believe there are 5 key drivers that determine the value proposition for a company to invest in 3D printing, be it in the form of outsourced services or capital expenditure. If these drivers resonate with opportunities and challenges you see in your business, it is likely that 3D printing can benefit you.

1. Accelerating Product Development

3D printing has its origins in technologies that enabled Rapid Prototyping (RP), a field that continues to have a significant impact in product development and is one most people are familiar with. As shown in Figure 1, PADT’s own product development process involves using prototypes for alpha and beta development and for testing. RP is a cost- and time effective way of iterating upon design ideas to find ones that work, without investing in expensive tooling and long lead times. If you work in product development you are very likely already using RP in your design cycle. Some of the considerations then become:

  • Are you leveraging the complete range of materials including high temperature polymers (such as ULTEM), Nylons and metals for your prototyping work? Many of these materials can be used in functional tests and not just form and fit assessments.
  • Should you outsource your RP work to a service bureau or purchase the equipment to do it in-house? This will be determined by your RP needs and one possibility is to purchase lower-cost equipment for your most basic RP jobs (using ABS, for example) and outsource only those jobs requiring specialized materials like the ones mentioned above.
PADT's Product Development process showing the role of prototypes (3D printed most of the time)
Figure 1. PADT’s Product Development process showing the role of prototypes (most often 3D printed)

The video below contains several examples of prototypes made by PADT using a range of technologies over the past two decades.

2. Exploiting Design Freedom

Due to its additive nature, 3D printing allows for the manufacturing of intricate part geometries that are prohibitively expensive (or in some cases impossible) to manufacture with traditional means. If you work with parts and designs that have complex geometries, or are finding your designs constrained by the requirements of manufacturing, 3D printing can help. This design freedom can be leveraged for several different benefits, four of which I list below:

2.1 Internal Features

As a result of its layer-by-layer approach to manufacturing a part, 3D printing enables complex internal geometries that are cost prohibitive or even impossible to manufacture with traditional means. The exhaust gas probe in Fig. 2 was developed by RSC engineering in partnership with Concept Laser has 6 internal pipes surrounded by cooling channels and was printed as one part.

3D Printed Exhaust Gas Probe (RSC Engineering and Concept Laser Inc.)
Fig 2. 3D Printed Exhaust Gas Probe with intricate internal features (RSC Engineering and Concept Laser Inc.)

2.2 Strength-to-Weight Optimization

One of the reasons the aerospace industry has been a leader in the application of 3D printing is the fact that you are now able to manufacture complex geometries that emerge from a topology optimization solution and reduce component weight, as shown in the bracket manufactured by Airbus in Figure 3.

Titanium Airbus bracket made by Concept Laser on board the A350
Fig 3. Titanium Airbus bracket made by Concept Laser on board the A350

2.3 Assembly Consolidation

The ability to work in a significantly less constrained design space also allows the designer to integrate parts in an assembly thereby reducing assembly costs and sourcing headaches. The part below (also from Airbus) is a fuel assembly that integrated 10 parts into 1 printed part.

Airbus Fuel Assembly 3D printed out of metal (Airbus / Concept Laser)
Fig 4. Airbus Fuel Assembly 3D printed out of metal (Airbus / Concept Laser)

2.4 Bio-inspiration

Nature provides several design cues, optimized through the process of evolution over millenia. Some of these include lattices and hierarchical structures. 3D printing makes it possible to translate more of these design concepts into engineering structures and parts for benefits of material usage minimization and property optimization. The titanium implant shown in Figure 5 exploits lattice designs to optimize the effective modulus in different locations to more closely represent the properties of an individuals bone in that region.

Titanium implant leveraging lattice designs (Concept Laser)
Fig 5. Titanium implant leveraging lattice designs (Concept Laser)

3. Simplifying the Supply Chain, Reducing Lead Times

One of the most significant impacts 3D printing has is on lead time reduction, and this is the reason why it is the preferred technology for “rapid” prototyping. Most users of 3D printing for end-part manufacturing identify a 70-90% reduction in lead time, primarily as a result of not requiring the manufacturing of tooling, reducing the need to identify one or more suppliers. Additionally, businesses can reduce their supplier management burden by in-sourcing the manufacturing of these parts. Finally, because of the reduced lead times, inventory levels can be significantly reduced. The US Air Force sees 3D printing as a key technology in improving their sustainability efforts to reduce the downtime associated with aircraft awaiting parts. Airbus recently also used 3D printing to print seat belt holders for their A310 – the original supplier was out of business and the cost and lead time to identify and re-tool a new supplier were far greater than 3D printed parts.

4. Reducing Costs for High Mix Low Volume Manufacturing

According to the 2015 Wohlers report, about 43% of the revenue generated in 3D printing comes from the manufacturing of functional, or end-use parts. When 3D printing is the process of choice for the actual manufacturing of end-use parts, it adds a direct cost to each unit manufactured (as opposed to an indirect R&D cost associated with developing the product). This cost, when compared to traditional means of manufacturing, is significantly lower for high mix low volume manufacturing (High Mix – LVM), and this is shown in Figure 6 for two extreme cases. At one extreme is mass customization, where each individual part has a unique geometry of construction (e.g. hearing aids, dental aligners) – in these cases, 3D printing is very likely to be the lowest cost manufacturing process. At the other end of the spectrum is High Volume Manufacturing (HVM) (e.g. semiconductor manufacturing, children’s toys), where the use of traditional methods lowers costs. The break-point lies somewhere in between and will vary by the the part being produced and the volumes anticipated. A unit cost assessment that includes the cost of labor, materials, equipment depreciation, facilities, floor space, tooling and other costs can aid with this determination.

Chart showing how volumes drive unit prices and where 3D Printing can be the cheaper option
Fig 6. Chart showing how volumes drive unit prices and where 3D Printing can be the cheaper option for low volumes and high mix manufacturing

5. Developing New Applications

Perhaps the most exciting aspect of 3D printing is how people all around the world are using it for new applications that go beyond improving upon conventional manufacturing techniques. Dr. Anthony Atala’s 2011 TED talk involved the demonstration of an early stage technique of depositing human kidney cells that could someday aid with kidney transplants (see Figure 7). Rarely does a week go by with some new 3D printing application making the news: space construction, 3D surgical guides, customized medicine to name a few. The elegant and intuitive method of building something layer-by-layer lends itself wonderfully to the imagination. And the ability to test and iterate rapidly with a 3D printer by your side allows for accelerating innovation at a rate unlike any manufacturing process that has come before it.

Dr. Anthony Atala showing a 3D printed kidney [Image Attr. Steve Jurvetson]
Fig 7. Dr. Anthony Atala showing a 3D printed kidney [Image Attr. Steve Jurvetson, Wikimedia Commons]

Conclusion

As I mentioned in the introduction, if you or your company have challenges and needs in one or more of the 5 areas above, it is unlikely to be a question of whether 3D printing can be of benefit to you (it will), but one of how you should best invest in it for maximum return. Further, it is likely that you will accrue a combination of benefits (such as assembly consolidation and supply simplification) across a range of parts, making this technology an attractive long term investment. At PADT, we offer 3D printing both as a service and also sell most of the printers we use on a daily basis and are thus well positioned to help you make this assessment, so contact us!