PADT Startup Spotlight – The Speed of Simulation

The Speed of Simulation  with Velox Motorsports

With thoroughly engineered components including the use of Finite Element Analysis (FEA), thermodynamics, heat transfer, and Computational Fluid Dynamics (CFD), PADT Startup Spotlight Velox Motorsports strives to produce aftermarket parts that can effectively outperform the factory components.

Join Velox Co-Owners Eric Hazen and Paul Lucas for a discussion on what they use ANSYS simulation software for and how they have benefited from it’s introduction into their manufacturing process.

This webinar will focus on two projects within which the engineers at Velox have see the impact of ANSYS, including:

Using Finite Element Analysis (FEA) to reverse engineer a Subaru fork, find the cause of failure and develop an improved replacement part.

Using Computational Fluid Dynamics (CFD) to rub a shape sensitivity study on Nissan GT R strakes, and develop a replacement that increases down-force without significantly increasing drag.

ANSYS 18 – SpaceClaim Webinar

In its latest release, ANSYS SpaceClaim further integrates its ease of use and rapid geometry manipulation capabilities into common simulation workflows. From large changes to behind the scenes enhancements, you’ll notice efficiency improvements across the board. You’ll save time automating geometry tasks with the expanded recording and replay capabilities of SpaceClaim’s enhanced scripting environment.

Join PADT’s Application Engineer Tyler Smith  for this webinar and learn about several improvements that are guaranteed to save time, enhance your designs and improve overall usability. We’ll cover:

  • Continued development of SpaceClaim’s scripting environment. With expanded recording capabilities and replayability of scripts on model versions, you’ll save time in the steps needed to automate geometry tasks.

  • Faceted data optimization and smoothing enhancements. You can greatly simplify and smooth topology optimized STL data for downstream printing, while preserving the integrity of localized regions.

  • Lattice Infilling for additive manufacturing. The Infilling functionality has greatly expanded to include several lattice infill types, all with custom options to ensure your 3-D printed component has an ideal strength-to-weight relationship.

  • Exploration of inner details of a model with the new fly-through capability. Without hiding components or using cross sections, this capability provides graphical feedback at your fingertips while making it even more enjoyable to work in a 3-D environment.

Kidneys and Child Hearts – Our Recent Real World Experiences with 3D Printing in Medicine

Mostly we make boxes.  Pretty boxes but the bulk of what we 3D Print is some sort of plastic box that people stuff electronics in to. Most of the time we also don’t really know what customers do with the objects we make for them.  But every once in a while you get involved in a project that really makes a difference. That could not be more true than two recent medical applications for 3D Printing that we worked on with Intermountain Healthcare (IHC) in Salt Lake City, Utah.

KSL, a local TV station, did a story on our IHC was deploying 3D Printing to produce better outcomes for their patients. You can view the story here.

PADT was fortunate enough to be part of two of the cases mentioned in the story.  The first was a St George man who was feeling some pain in his back. He had a scan and they found 12 kidney stones.  On top of that, his kidney was not in the right place and was distorted.  PADT helped print a model of the scan so that the doctors could just get a real feel for what they were dealing with, and then plan the surgery.

The second situation really pulled at our heart strings.  A 10 year old boy needs heart surgery and its a complicated problem. They need a model fast so we worked with Stratasy to quickly print an accurate model so tha the surgeons could come up with a plan. We still have not heard how it went, they are scheduling things, but the feedback from the team was that the 3D model was extremely helpful.  We are talking life saving.

Both of these recent situations build on years of examples where we have worked the doctors and their technical assistance to convert scans of patients into usable 3D Models. If you are in the surgery or surgery planning space and want to learn more about how accurate 3D models printed directly from scan data can be used to improve patient outcome, contact PADT at info@padtinc.com and we will connect you with our 3D Printing team.

How-To: Creating Matching Faces on Touching Parts with ANSYS SpaceClaim

Sometimes you want to take two parts and and prepare them for meshing so that they either share a surface between them, or have identical but distinct surfaces on each part where they touch.  In this simple How-To, we share the steps for creating both of these situations so you can get a continuous mesh or create a matching contact surface in ANSYS Mechanical.

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How-To: Connecting Shells Elements in Surface Models with ANSYS SpaceClaim and ANSYS Mechanical

By using the power of ANSYS SpaceClaim to quickly modify geometry, you can set up your surface models in ANSYS Mechanical to easily be connected.  Take a look in this How-To slide deck to see how easy it is to extend geometry and intersect surfaces.

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Coupling ANSYS Mechanical and Flownex

The below example demontrates how to couple Flownex and ANSYS mechanical using the Mechanical Generic Interface component.

For those that don’t know, Flownex is a thermal-fluid system modeling tool that is great for modeling heat, flow, pressure, etc… in systems.  At PADT we often connect it to ANSYS Mechanical to do more detailed component level simulation when needed. 

Why the need for the link in the fist place?

  • It is an automated workflow to couple Flownex and ANSYS through direct mapping of Flownex results (HTC and bulk temperatures) as boundary condition to an ANSYS thermal analysis.
  • Represents a conjugate heat transfer model with fluid calculations handled in Flownex
  • Allows one to easily/quickly investigate fluid flow and heat transfer properties under a wide range operating conditions.

First we will discuss the steady state thermal ANSYS Mechanical model that will be linked to Flownex.

We have a pipe Pipe with arbritraty geometry and material properties. Convection boundary conditions have been applied to both the internal and external pipe walls. The inernal Bulk Temperature will be supplied by Flownex.

  • External BC
    • HTC 100 w/m2K
    • Bulk Temperature 22C
  • Internal BC
    • HTC 1500 w/m2K
    • Bulk Temperature will be supplied by Flownex

A command snippet, which will calculate the total heat flow through the inner wall surface and write the value out into a text file called d_result, has been inlcuded in the ANSYS Mechanical model.

In order to achieve a bidirectional coupling, Flownex will execute the Mechanical APDL batch file. We can generate the Mechanical APDL batch file (ds.dat), from within Mechanical.

The soluiton procedure is as follows

  1. Flownex modifies the ds.dat file
  2. Flownex executes the modified ds.dat file
  3. The modified ds.dat file generates the d_result.txt file
  4. Flownex reads the d_result.txt file
  5. Flownex executes an iteration, using value from d_result.txt
  6. Repeat untill solutions are converged.

The next step after creating the ds.dat file is to set up your Flownex model.

The Flownex model comprises of a pipe component with arbritrary geomery, filled with air with an inlet temperature and pressure of 500˚C and 120 kPa respectilvy and a flow rate of approximatly 1kg/s.

We have connected the pipe component to the Mechanical Generic Interface using data transfer links.

The data transfer links pass the bulk fluid temperature form the pipe to the Mechanical Generic Interface component, and return the heat flow value calculated using ANSYS to the pipe.

Next we need place the ds.dat file in the AnsysMechanical_Files folder which is located in the Flownex project folder. It is necessary to create a copy of the ds.dat called ModifiedData.dat in the same location.

Let’s go over the inputs to the Mechanical Generic Interface component in Flownex:

1) Executable location

C:\Program Files\ANSYS Inc\v180\ansys\bin\winx64\Ansys180.exe

This is the path to ANSYS executable. Pay particular attention to the version number (eg 180, 172), as this will be different depending on the version of ANSYS you have installed.

2) Command line parameters

-b -i ModifiedData.dat -o results

Flownex will launch ANSYS, and execute the ModifiedData.dat Mechanical APDL batch file from the command line, using the above command a detailed description of command line options can be found in another blog post here.

3) Project files folder, Data file name and Modified data file name

Here we specify location of the Mechanical APDL batch files

4) Inputs

Here we will define where in ModifiedData.dat the value from Flownex, fluid temperature in this case, will be placed. This is done by determining what the boundary condition variable and ID is, and finding the prefix before the boundary condition value in the ds.dat file. Typically the variable for temperature is _loadvari and for HTC it is _convari.

It is possible to know the boundary condition ID by activating the appearance of Beta options in WB.

5) Outputs

Here we will specify the location of the d_result.txt that ANSYS generates. It should appear in the same folder as the Mechanical APDL batch files after successful execution.

Flownex and ANSYS will pass data back and forth every time step of a transient Flownex run.

The simulation should continue to run up to, and beyond the point where the Flownex and ANSYS simulation have converged. If we plot out the heat input or temperature value vs time we should be able to visualize convergence, akin to residual plots when running a CFD simulation, and then manually stop the simulation after values have stabilized.

Below we increase the fluid inlet temperature form 500˚C to 1000˚C after 10 iterations, and observed a increase in heat flow from ~1.4kW to ~2.8kW.

Silicon Desert Insider: Self-driving cars are driving big changes in tech

Everywhere you drive in Phoenix you see autonomous cars being tested.  These are cool and all, but they also are a sign of a whole new boom in technological change. In “Self-driving cars are driving big changes in tech” I go over some of the key disruptive innovations that will be driven by these new vehicles.

Phoenix Business Journal: 3 keys to success for smart home devices

When Cox Communications asked us to be part of its local Smart Home Tour I said yes for one simple reason: I wanted to see a truly connected home. in “3 keys to success for smart home devices” I discuss some of the lessons I learned about IoT devices that actually work in the home.

Installing a Metal 3D Printer: Part 2 (Facilities)

This is part 2 of a 5-part post on the lessons we learned installing our first Metal 3D printer, a Concept Laser MLab Cusing R. Please read the first post if you haven’t already, where I listed all the different equipment (in addition to the 3D printer itself) one needs to run this process, available at this link.

A reminder at the outset: these posts are meant to be informative only, to give you a sense of what questions you need to ask and get answers to. Specific requirements will vary by equipment and your site specific needs.

1. Electrical

Most metal 3D printers, including the Concept Laser machines, are manufactured in Europe and have electrical requirements that differ from what most American machine shops are setup for (which is the scope of this section). If you have installed 230 V European equipment before and know what L-N and PE stand for and how they differ between European and American systems, you can skip this section. If not, read on.

There are two key items here one needs to be aware of: first of course is the fact that these pieces of equipment typically run on single-phase 230 V (3-phase 400V for the very large machines like Concept Laser’s XLine 2000R) as opposed to the standard 110V. Secondly, and this is easier to miss, European electrical connections have one “hot” line (L) for a single-phase, one Neutral line (N) and one Protected Earth (PE) – this is different from the US standard where you have 2 “hot” lines and 1 ground. The reason for these differences and how to address them electrically is beyond the scope of this post (or my understanding), but the main point is to have an electrician familiar with European codes review this early on. A dedicated custom transformer for all your European 230V equipment is one solution, and the one we employed here at PADT, as shown in Figure 1. (I rarely give shout-outs, but our experience with Fargo Electric on procuring a custom, affordable transformer was one of the best transactions I have ever had.)

electrical-european
Fig 1. Dedicated transformer in use for PADT’s metal 3D printer. Also note the L-N-PE connections and the plugs used on the different equipment.

2. Inert Gas

nitrogen
Fig 2. Nitrogen line running to our MLab

Laser melting of powder metals needs to be conducted in an inert atmosphere. Most suppliers recommend using Argon for Aluminum and Titanium alloys, but that Nitrogen is fine for the non-reactive alloys such as steel, Inconel and Cobalt-Chrome alloys. At PADT, we leveraged our existing nitrogen generator and added an additional line running to our metal 3D printer (Figure 2). Before doing this, you need to add up all the consumption rates for the machines (at their peaks) to make sure you don’t exceed the generator’s capabilities. It is a good idea to demarcate space for Argon cylinders should you need them at a later stage.

3. ESD Mats or Floors (for Reactive Metals)

As we will see in the next blog post in this series, avoiding charge dissipation into metal powder is a key safety requirement for operating metal 3D printers – this is achieved through a range of strategies like ESD (Electro Static Discharge) armbands, grounding wires etc. If you plan on running reactive metals and especially if you expect to have many operators, an ESD coated floor with ESD shoes or boot straps, along with an ESD meter (like the one Honeywell installed at their facility) is a good strategy. From personal experience with ESD boot straps, I know these can be fickle in passing an ESD meter test. Connecting the ESD meter to the entryway door so entry is only provided after passing the test is one way to ensure only those with functioning straps enter the workspace. For those without this strategy, grounded ESD mats and ESD armbands connected to the machine are also alternative strategies which I will discuss in more detail in the next post. From a facilities standpoint, if you do want to enable ESD coated floors, boot straps and ESD meters, you need to plan this early, which is why I have included it here.

4. Water

Fig 3. Water column in a wet separator – this has to be cleaned out and replenished frequently

Access to running water is essential for cleaning the wet separator (vacuum) that is used for sucking up fugitive powder – ideally the water source is near your liquid waste storage so you can clean out the wet separator and pour the powder-contaminated water into storage. Alternatively, you can also use a garden sprayer for smaller machines, like we do at PADT. Fill up the sprayer with water and use it to rinse out the wet separator right on top of the waste storage bin.

Another reason you need access to water is to passivate the filter. While not all OEMs recommend water passivation, Concept Laser does and we find it to be very user friendly, as I demonstrate in the video below (video starts 2:58 in, which is when I discuss filter passivation with water).

 5. Access Control

It is important to restrict access to your metal AM laboratory through badge scanning or key pad entry to those who are trained on using the machine, and your building facilities team. It also helps to provide as much visibility through glass windows so that folks that are entering can study what activity is in progress before entering.

Fig 4. Door lock with combination to restrict access, window to provide visibility

6. Structure & Ventilation

Here I move into the subjective (gray area) domain – I request anyone who has more specific information on these matters to kindly share them with me for inclusion in this post (with due credit). I have heard anecdotally that in some places the city has required the supplier to install blast walls and other explosion resistant infrastructure – yet others have not required such infrastructure (including ours). I am not well informed in this space and can only emphasize the need to have these discussions out in the open in the early stage of planning your facility and ask your city’s building safety person if the walls you have planned (or already have installed) are adequate or not – this is likely to be a function of the amount and reactivity of the powder you are handling, proximity to vulnerable areas, human occupancy and other concerns. With regard to ventilation, the more open the space the better (these machines can heat up a small, closed room) – at the same time the space needs to be sealed off from the elements including wind. I know this too is a subjective matter, so discussions with city representatives are the best way to go.

Please send any of your comments, questions or suggestions for improvement to info@padtinc.com, citing this blog post, or connect with me on LinkedIn.

And now go on to PART 3 (SAFETY)

Acknowledgements

Special thanks to Gregg Rand at PADT, Martin Perez (City of Phoenix) and Dave Tallman (City of Tempe), and engineers at Concept Laser Inc.

Increase your throughput and reduce manufacturing costs

Fast, easy to use lightweighting for structural analysis is now only a few clicks away thanks to the introduction of Topology Optimization in ANSYS 18.

Engineers who use Finite Element Analysis (FEA) can reduce weight, materials, and cost without switching tools or environments. Along with this, Topology Optimization frees designers from constraints or preconceptions, helping to produce the best shape to fulfill their project’s requirements.

Topology Optimization also works hand-in-hand with Additive Manufacturing; a form of 3D printing where parts are designed, validated, and then produced by adding layers of material until the full piece is formed. Pairing the two simply allows users to carry out the trend of more efficient manufacturing through the entirety of their process.

Join PADT’s simulation support manager Ted Harris for a live presentation on the full
benefits of introducing Topology Optimization into your manufacturing process. This webinar will cover:

  • A brief introduction into the background of Topology Optimization and Additive Manufacturing, along with an overview of it’s capabilities

  • An explanation of the features available within this tool and a run through of it’s user interface and overall usage

  • An in-depth look at some of the intricacies involved with using the tool as well as the effectiveness of it’s design workflow

Thoughts from my day in a smart home – the importance of connecting right

When I was asked to take part in a demonstration put on by one of our local communication companies, Cox Communications, showing off what a “smart home” looks like, I of course said yes.  I love gadgets, and smart gadgets more.  On top of that it was another chance to evangelise on the power of 3D Printing.  And I got to hang out in a brand new luxury condo in Downtown Phoenix, a post kid lifestyle change that is very appealing.  Plus we deal with customers designing and improving Internet of Things (IoT) devices all the time, and this is the perfect chance to see such products in action.

So I packed up one of our Makerbots, none of our Fortus machines fits in the back of my Prius, and headed downtown.  The first thing that shocked me was that I had the printer, my iPhone, iPad, and laptop connected to their network in about one minute.  The printer showed up on the Makerbot Print app on my iPad and I was printing a part in about three minutes.

My station, showing off 3D Printing in the home.

The whole point of the demonstration was to show how the new high-speed Internet offering from Cox, Gigablast, can enable a true smart home.  So I was focused on the speed of the connection to the Internet, which was fast.  What I didn’t get till I connected was that the speed and bandwidth of the WiFi in the house was even more important.

When everything was connected, we had 55 devices on the local network talking to each other and the Internet. At one point I was downloading a large STL file to the printer while on a teleconference on my iPhone and my “roommate” was giving a violin lesson to one of his students in Canada.

Oh, and the roomba started to vacuum the floor. On the balcony someone was giving a golf lesson and a doctor was diagnosing a patient in the master bedroom.  That was on top of the smart kitchen gadgets.  And it all worked.  Yes, it all worked.

I’m trying to convey shock and surprise because the reality is that nine times out of ten when I show up for some event, at a customer, or at a friends house and we try and connect things to the internet… it doesn’t work.  If you are a technical guy you know that feeling when your vacation or visit for dinner turns into an IT house call.  All I could think of was how awesome it was that everything worked and it was fast.

So I went to work printing little plastic Arizona style houses with COX on the roof. And then a reporter showed up. “3D Printing, interesting.  Hmmmm…  they are cool and all but really, what does that have to do with a smart house?”  Damn reporters and their questions.  I was still reveling in the fact that everything worked so well, I hadn’t taken to time to think about the “so what.”

Then I thought about it.  3D Printing in the home is just now starting to take off, and the reason why is actually high-speed internet connections. If you wanted a 3D Printer in your home in the past you needed the printer, a high end computer, and some good 3D modeling software on that computer.  Basically you had to create whatever you wanted to make.  Unless you are a trained engineer, that may not be so easy.

My “house” that I was printing at the invent sits on the cloud in my Thingiverse account.

But with a well connected home you have access to places like Thingiverse and Grabcad to download stuff you want to print.  And if you do want to create your own, you can go to Tinkercad or Onshape and use a free online 3D modeler to create your geometry.  All over the web, even on a pad, phone (I don’t recommend trying to do modeling on a phone, but it does work), or on a basic computer.  The files are stored in the cloud and downloaded directly to your printer.  No muss, no fuss.  All you need is a reliable and fast connection to the internet and in your home.

High speed internet and a smart 3D printer makes anyone a maker.

And when we had a three hour break, I went downstairs to a coffee shop on the ground floor of the condo and worked, while monitoring my builds using the camera in the smart 3D Printer.

Pretty cool when you step back and think about how far we have come from that first Stereolithography machine that PADT bought in 1994.  We had to use floppy disks to get the data from our high-end Unix workstation to the machine.  Now it sits on the web and can be monitored.

This may be what we have been waiting for when it comes to 3D Printers in the home moving beyond that technologists and makers.

I’ve been focused on my experience with the 3D printing in the smart home, but there was a lot more to look at.  Check out these stories to learn more:

Phoenix Business Journal: Cox shows off a smart home with 55 connected devices and fast gigabyte internet

The Arizona Republic: Cox ‘smart home’ in Phoenix displays future at the push of a button

I also did a piece for the Phoenix Business Journal while I was at the event on “3 keys to success for smart home devices” based on what I learned while playing with the other devices in the smart home.

All and all a good day.  Oh, and being a 10 minute walk from my favorite pub made the idea of living downtown not such a bad idea, which doesn’t have much to do with high speed internet, connected devices, or 3D Printing.  But one of my goals was to check out post-child urban living…

 

 

Phoenix Business Journal: 6 ways to adapt your business model to disruptive technology

Technology is always changing, and it is changing faster and in more ways. Even if your business is not a “technology” business, new ways of doing things, new business models, and new ways of communicating will impact your business. In “6 ways to adapt your business model to disruptive technology” I explore six simple things that you can do to not just avoid harm by, but to take advantage of disruptive technologies.

Installing a Metal 3D Printer: Part 1 (Equipment)

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Fig 1. Concept Laser MLab Cusing R in PADT’s Metal 3D Printing Lab

What equipment does one need for metal 3D printing? 

This is the first in a five-part series that brings together the different lessons we learned installing our first metal printer, a Concept Laser MLab Cusing R at PADT, shown in Figure 1. In this post I list the different equipment needed to enable metal 3D printing end-to-end, along with a brief explanation of its purpose. In subsequent posts, I deal with (2) Facilities, (3) Safety, (4) Environmental & (5) Housekeeping aspects of the technology. I hope this information adds to the conversation in a meaningful way and help those who are thinking about, or in the process of installing a metal 3D printer.

The specifics of some of this information will vary depending on the equipment and materials you handle, but my hope is the themes covered here give you a sense of what is involved in installing a metal 3D printer to aid in your preparation for doing the same and for having good discussions with your equipment supplier to ensure these are addressed at a minimum.

One way to look at classifying the equipment needed (beyond the obvious metal 3D printer!) is by its purpose, and I do so here by dividing it into two broad categories: Ancillary Equipment (necessary to the printing itself) and Post-Processing Equipment (focused on the part).

At the outset, it is crucial that the difference between reactive and non-reactive metal alloys be comprehended since a lot of the use of the equipment differs depending on what kind of metal alloy is being used. A previous blog post addressed these differences and these terms will be used in the following sections.

1. Ancillary Equipment

1.1 Wet Separator

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Fig 2. Wet separator used to vacuum fugitive powder

The wet separator is essentially a vacuum cleaner that is designed to safely vacuum stray (“fugitive”) metal powders that cannot be cleaned up any other way. When dealing with powders, the typical recommendation is to first brush whatever you can into the overflow bin so you can reuse it. The next step is to try and wipe up powder with a moist lint-free cloth (to be covered in the housekeeping post). The wet separator has a water column that passivates the metal powder and renders it non-reactive to allow for easier disposal (to be covered in the environmental post). Wet separators require a significant amount of maintenance, particularly when dealing with reactive metals like Titanium and Aluminum alloys, where the supplier recommends the wet separator be cleaned out on a daily basis. At least one company has developed a kit to help with wet separator cleaning – which gives you an indication of how significant of an issue this is. Most suppliers provide a wet separator along with their equipment.

1.2 Glove Box

glove-box
Fig 3. Glove box used to interact with the build chamber in a safe manner, and in an inert atmosphere for reactive metals

A glove box is a useful piece of equipment for dealing with reactive metals in particular. The glove box allows an operator to manage all the powder handling in the build chamber to be done in a closed environment. For non-reactive metals this is not a necessary piece of equipment but it is highly recommended for reactive metals. The glove box when used in concert with reactive metals will allow for inert gas flushing out of oxygen to low PPM levels prior to operator intervention, and also includes grounding connections for the box to the machine. The nice thing about having a glove box is it reduces the amount of time you need to have a respirator on by allowing you to add powder and unpack builds in a closed environment. The glove box may also be integrated into the machine itself – ours is a stand alone device on wheels that we roll over to the machine when we need it.

1.3 Powder Sieve

Unless you plan on disposing all the powder in each build after it is completed, you need a sieve to separate out the larger particles and contaminants from the powder you wish to reuse in subsequent builds. The sieves are also typically provided with the machine and can be enabled with inerting capability (as shown in Fig 4 on the left, or as shown on the right, come as a small desktop unit that can sieve about 3-5 lbs of powder at a time). While the sieve on the left may be used for reactive metal sieving, it is uncertain if one can safely use the desktop sieve for the same, even with grounding the table it sits on and the operator – this is a gray area and I am keen to hear thoughts on this from those that have the expertise/experience in this space.

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Fig 4. Mechanical sieving: (left) for large quantity sieving, (right) tabletop model for smaller quantities

1.4 Ultrasonic Cleaner

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Fig 5. Ultrasonic cleaner used to help isolate metal powder trapped inside parts and supports

The purpose of the ultrasonic cleaner is to remove as much trapped powder as possible before the part and the build plate are subjected to any post-processing – this is to minimize the risk of trapped powder getting airborne during downstream processes – which cannot be completely eliminated (which is why PPE should be used all the way through till the final part is in hand after cleaning).

The Ultrasonic cleaner is used twice: first before the parts are removed from the build plate, and again after they are removed. Sometimes I will even use it a third time after all supports have been removed, if the part has internal p. I typically use the 40 kHz and 60 C temperature setting but have not sought to further optimize the parameters at this time.

2. Post-Processing Equipment

2.1 Furnace

Fig 6. Radiation heating furnace with inert gas capability. The Nabertherm 7/H has a maximum temperature of 1280 C, suitable for stress relief.

The purpose of the furnace is to relieve residual stresses built in the parts prior to removing them from the build plate. So this is the first step after the parts and the plate come out of the ultrasonic cleaner. We use a furnace that allows for nitrogen or argon flushing, and place our parts wrapped in stainless steel foil in a gas box. Instructions for heat treatment (time and temperature profile) are typically provided on the technical specifications that come with the material. Metals like stainless steel can be stress relieved in a nitrogen atmosphere but Inconels and Ti6Al4V for example require higher temperatures of between 800-1000 C and argon atmospheres – so you need to be setup for both gases if you are considering running more than 1 metal in your operation.

2.2 Support Removal

All parts are connected to the build plate by between 3-5mm of supports that need to be removed. This is a two step process: the first step involves removing the parts with supports off the build plate, and this is most commonly done with a table saw or a wire EDM. At PADT, we stumbled upon a third way to do this, using an oscillating hand tool and a carbide blade – which works well for small parts (<3″ in X-Y space). It is important to always wear gloves and a supplier recommended (N95 or higher) respirator while removing supports since there could be trapped powder in the supports that was not removed with the Ultrasonic cleaner. The second step is to use hand tools to pry out the supports from the part – this is why it is important to design supports that have weak mechanical connections to the part itself – ideally you can tear them off with hand tools like a perforated sheet of paper [Video below courtesy Bob Baker at PADT, Inc].

2.3 Die Grinder

Fig 7. Die grinder used for removing burrs at the support interfaces on the part

A carbide die grinder is then used to grind away the support-model interface – for tiny parts, this can be achieved with a hand file as well for some parts but is easier to do with a die grinder. For large parts, this need can be eliminated by designing in regions that are to be machined later and aligning these regions with supported regions, so as to reduce the need for finishing on these surfaces.

2.4 Face Milling

This may come as a bit of a surprise, but you also need some way of replenishing the build plates after use so you can re-use the plates – this involves using a face milling technique to remove all the remnant supports on the build plate and take off a thin slice at the top of the build plate, while retaining flatness to within 100 microns (0.004″). Having this capability in-house will greatly speed-up your ability to start successive prints and reduce the need to keep large inventories of build plates [Video below courtesy Bob Baker at PADT, Inc].

2.5 Surface Finishing

A combination of techniques can be used for surface finishing. At a minimum, you must have the ability to do glass bead blasting – this is both for the printed parts, but also for the build plate itself – a bead blasted finish is recommended to improve the adhesion of the first layer of powder to the build plate.

Fig 8. (left) Bead blaster and (right) post-processed build plates, ready for use again

2.6 Other Capabilities

The list above is what I would consider a minimum list of capabilities one needs to get started in metal 3D printing, but is not comprehensive and does not include facility, safety, environmental and housekeeping requirements which I will cover in future posts. Additional CNC equipment for machining metal AM parts, heat treatment and HIP, and superior surface finishing and cleaning techniques are often called upon for metal AM production, but these are highly dependent on application and part design, which is why I have left them out of the above list.

Move on to part 2 of this series where I discuss the facilities requirements for metal 3D printing (electrical, inert gas etc.). Did I miss anything or do you have a better way of doing the things described above? Please send your thoughts to info@padtinc.com, citing this blog post, or connect with me on LinkedIn.

Acknowledgements:
Garrett Garner at Concept Laser, Inc and Bob Baker at PADT, Inc. for their insight and expertise that helped us select and bring in the above capabilities at PADT.

CLICK HERE for part 2

Introducing our new Newsletter: The PADT Pulse

We are very pleased to announce our new newsletter, the PADT Pulse.  For a while now customers have been asking for a monthly update on what is going on without having to go through our blog. So we are taking the best of what we did in a given month and sharing it in this newsletter.

Not only does it have a recap of important activities, it summarizes our most popular blog posts, shares some outside news of interest, and keeps you up to date on our upcoming events. We hope you enjoy it.

Here is a link to the online version.

And you can subscribe here.

ASU Polytechnique Deploys Robots in Project for 3D Printing Automation for Orbital ATK

Sometimes we run across some great exampls of industry and academia working together and like to share them as examples of win-win partnerships that can move technology forward and give studends a great oportunity.   A current Capstone Design Project by students at ASU Polytechnique is a great example.  It is also an early exmple of what can be done at the brand new Additive Manufacturing Center that was recently opened at the campus.

I’ll let ASU Mecanical Enginering Systems student Dean McBride tell you in his own words:

Orbital ATK in Chandler currently utilizes two Stratasys Dimension SST 1200es printers to prototype various parts with.  These printers print on parts trays, which must be removed and re-inserted into the printer to start new prints.  Wanting to increase process efficiency, Orbital had the desire of automating this 3D printing process during times when employees are not present to run the printers.  After the idea was born, Orbital presented this project to ASU Polytechnic as a potential senior capstone design project.  Shortly after, an ambitious team was assembled to take on the project.

 Numerous iterations of the engineering design process took place, and the team finally arrived at a final solution.  This solution is a Cartesian style robot, meaning the robot moves in linear motions, similar to the 1200es printer itself.  The mechanical frame and structure of the robot have been mostly assembled at this point.  Once assembly is achieved, the team will focus their efforts on the electrical system of the robot, as well as software coding of the micro-controller control system.  The team will be working to fine tune all aspects of the system until early May when the school semester ends.  The final goal of this project is to automate at least two complete print cycles without human interaction.

Here is a picture of the team with the robot they are building along side the Stratasys FDM printer they are automating.