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

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

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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!

Constitutive Modeling of 3D Printed FDM Parts: Part 2 (Approaches)

In part 1 of this two-part post, I reviewed the challenges in the constitutive modeling of 3D printed parts using the Fused Deposition Modeling (FDM) process. In this second part, I discuss some of the approaches that may be used to enable analyses of FDM parts even in presence of these challenges. I present them below in increasing order of the detail captured by the model.

  • Conservative Value: The simplest method is to represent the material with an isotropic material model using the most conservative value of the 3 directions specified in the material datasheet, such as the one from Stratasys shown below for ULTEM-9085 showing the lower of the two modulii selected. The conservative value can be selected based on the desired risk assessment (e.g. lower modulus if maximum deflection is the key concern). This simplification brings with it a few problems:
    • The material property reported is only good for the specific build parameters, stacking and layer thickness used in the creation of the samples used to collect the data
    • This gives no insight into build orientation or processing conditions that can be improved and as such has limited value to an anlayst seeking to use simulation to improve part design and performance
    • Finally, in terms of failure prediction, the conservative value approach disregards inter-layer effects and defects described in the previous blog post and is not recommended to be used for this reason
ULTEM-9085 datasheet from Stratasys - selecting the conservative value is the easiest way to enable preliminary analysis
ULTEM-9085 datasheet from Stratasys – selecting the conservative value is the easiest way to enable preliminary analysis
  • Orthotropic Properties: A significant improvement from an isotropic assumption is to develop a constitutive model with orthotropic properties, which has properties defined in all three directions. Solid mechanicians will recognize the equation below as the compliance matrix representation of the Hooke’s Law for an orthortropic material, with the strain matrix on the left equal to the compliance matrix by the stress matrix on the right. The large compliance matrix in the middle is composed of three elastic modulii (E), Poisson’s ratios (v) and shear modulii (G) that need to be determined experimentally.
Hooke's Law for Orthotropic Materials (Compliance Form)
Hooke’s Law for Orthotropic Materials (Compliance Form)

Good agreement between numerical and experimental results can be achieved using orthotropic properties when the structures being modeled are simple rectangular structures with uniaxial loading states. In addition to require extensive testing to collect this data set (as shown in this 2007 Master’s thesis), this approach does have a few limitations. Like the isotropic assumption, it is only valid for the specific set of build parameters that were used to manufacture the test samples from which the data was initially obtained. Additionally, since the model has no explicit sense of layers and inter-layer effects, it is unlikely to perform well at stresses leading up to failure, especially for complex loading conditions.  This was shown in a 2010 paper that demonstrated these limitations  in the analysis of a bracket that itself was built in three different orientations. The authors concluded however that there was good agreement at low loads and deflections for all build directions, and that the margin of error as load increased varied across the three build orientations.

An FDM bracket modeled with Orthotropic properties compared to experimentally observed results
An FDM bracket modeled with Orthotropic properties compared to experimentally observed results
  • Laminar Composite Theory: The FDM process results in structures that are very similar to laminar composites, with a stack of plies consisting of individual fibers/filaments laid down next to each other. The only difference is the absence of a matrix binder – in the FDM process, the filaments fuse with neighboring filaments to form a meso-structure. As shown in this 2014 project report, a laminar approach allows one to model different ply raster angles that are not possible with the orthotropic approach. This is exciting because it could expand insight into optimizing raster angles for optimum performance of a part, and in theory reduce the experimental datasets needed to develop models. At this time however, there is very limited data validating predicted values against experiments. ANSYS and other software that have been designed for composite modeling (see image below from ANSYS Composite PrepPost) can be used as starting points to explore this space.
Schematic of a laminate build-up as analyzed in ANSYS Composite PrepPost
Schematic of a laminate build-up as analyzed in ANSYS Composite PrepPost
  • Hybrid Tool-path Composite Representation: One of the limitations of the above approach is that it does not model any of the details within the layer. As we saw in part 1 of this post, each layer is composed of tool-paths that leave behind voids and curvature errors that could be significant in simulation, particularly in failure modeling. Perhaps the most promising approach to modeling FDM parts is to explicitly link tool-path information in the build software to the analysis software. Coupling this with existing composite simulation is another potential idea that would help reduce computational expense. This is an idea I have captured below in the schematic that shows one possible way this could be done, using ANSYS Composite PrepPost as an example platform.
Potential approach to blending toolpath information with composite analysis software
Potential approach to blending toolpath information with composite analysis software

Discussion: At the present moment, the orthotropic approach is perhaps the most appropriate method for modeling parts since it is allows some level of build orientation optimization, as well as for meaningful design comparisons and comparison to bulk properties one may expect from alternative technologies such as injection molding. However, as the application of FDM in end-use parts increases, the demands on simulation are also likely to increase, one of which will involve representing these materials more accurately than continuum solids.

Constitutive Modeling of 3D Printed FDM Parts: Part 1 (Challenges)

As I showed in a prior blog post, Fused Deposition Modeling (FDM) is increasingly being used to make functional plastic parts in the aerospace industry. All functional parts have an expected performance that they must sustain during their lifetime. Ensuring this performance is attained is crucial for aerospace components, but important in all applications. Finite Element Analysis (FEA) is an important predictor of part performance in a wide range of indusrties, but this is not straightforward for the simulation of FDM parts due to difficulties in accurately representing the material behavior in a constitutive model. In part 1 of this article, I list some of the challenges in the development of constitutive models for FDM parts. In part 2, I will discuss possible approaches to addressing these challenges while developing constitutive models that offer some value to the analyst.

It helps to first take a look at the fundamental multi-scale structure of an FDM part. A 2002 paper by Li et. al. details the multi-scale structure of an FDM part as it is built up from individually deposited filaments all the way to a three-dimensional part as shown in the image below.

Multiscale structure of an FDM part
Multiscale structure of an FDM part

This multi-scale structure, and the deposition process inherent to FDM, make for 4 challenges that need to be accounted for in any constitutive modeling effort.

  • Anisotropy: The first challenge is clear from the above image – FDM parts have different structure depending on which direction you look at the part from. Their layered structure is more akin to composites than traditional plastics from injection molding. For ULTEM-9085, which is one of the high temperature polymers available from Stratasys, the datasheets clearly show a difference in properties depending on the orientation the part was built in, as seen in the table below with some select mechanical properties.
Stratasys ULTEM 9085 datasheet material properties showing anisotropy
Stratasys ULTEM 9085 datasheet material properties showing anisotropy
  • Toolpath Definition: In addition to the variation in material properties that arise from the layered approach in the FDM process, there is significant variation possible within a layer in terms of how toolpaths are defined: this is essentially the layout of how the filament is deposited. Specifically, there are at least 4 parameters in a layer as shown in the image below (filament width, raster to raster air gap, perimeter to raster air gap and the raster angle). I compiled data from two sources (Stratasys’ data sheet and a 2011 paper by Bagsik et al that show how for ULTEM 9085, the Ultimate Tensile Strength varies as a function of not just build orientation, but also as a function of the parameter settings – the yellow bars show the best condition the authors were able to achieve against the orange and gray bars that represent the default settings in the tool.  The blue bar represents the value reported for injection molded ULTEM 9085.
Ultimate Tensile Strength of FDM ULTEM 9085 for three different build orientations, compared to injection molded value (84 MPa) for two different data sources, and two different process parameter settings from the same source. On the right are shown the different orientations and process parameters varied.
Ultimate Tensile Strength of FDM ULTEM 9085 for three different build orientations, compared to injection molded value (84 MPa) for two different data sources, and two different process parameter settings from the same source. On the right are shown the different orientations and process parameters varied.
  • Layer Thickness: Most FDM tools offer a range of layer thicknesses, typical values ranging from 0.005″ to 0.013″. It is well known that thicker layers have greater strength than thinner ones. Thinner layers are generally used when finer feature detail or smoother surfaces are prioritized over out-of-plane strength of the part. In fact, Stratasys’s values above are specified for the default 0.010″ thickness layer only.
  • Defects: Like all manufacturing processes, improper material and machine performance and setup and other conditions may lead to process defects, but those are not ones that constitutive models typically account for. Additionally and somewhat unique to 3D printing technologies, interactions of build sheet and support structures can also influence properties, though there is little understanding of how significant these are. There are additional defects that arise from purely geometric limitations of the FDM process, and may influence properties of parts, particularly relating to crack initiation and propagation. These were classified by Huang in a 2014 Ph.D. thesis as surface and internal defects.
    • Surface defects include the staircase error shown below, but can also come from curve-approximation errors in the originating STL file.
    • Internal defects include voids just inside the perimeter (at the contour-raster intersection) as well as within rasters. Voids around the perimeter occur either due to normal raster curvature or are attributable to raster discontinuities.
FDM Defects: Staircase error (top), Internal defects (bottom)
FDM Defects: Staircase error (top), Internal defects (bottom)

Thus, any constitutive model for FDM that is to accurately predict a part’s response needs to account for its anisotropy, be informed by the specifics of the process parameters that were involved in creating the part and ensure that geometric non-idealities are comprehended or shown to be insignificant. In my next blog post, I will describe a few ways these challenges can be addressed, along with the pros and cons of each approach.

Click here to see part 2 of this post

3D Printed Plastics in Functional Aerospace Parts

Fused Deposition Modeling (FDM) is the most widely used 3D printing technology today, ranging from desktop printers to industrial scale manufacturing tools. While the use of FDM for prototyping and rapid tooling is well established, its use for manufacturing end-use parts in aerospace is a more recent phenomenon. This has been brought about primarily due to the availability of one material choice in particular: ULTEM. ULTEM is a thermoplastic that delivers compliance with FAA FAR 25.853 requirements. It features inherent flame retardant behavior and provides a high strength-to-weight ratio, outstanding elevated thermal resistance, high strength and stiffness and broad chemical resistance (official SABIC press release).

During an industry scan I conducted for a recent research proposal PADT submitted, I came across several examples of the aerospace industry using the FDM process to manufacture end-use parts. Each of these examples is interesting because they demonstrate the different criteria that make FDM preferable over traditional options, and I have classified them accordingly into: design opportunity, cost and lead-time reduction, and supply complexity.

Design Opportunity: In this category, I include parts that were primarily selected for 3D printing because of the unique design freedom that layer-wise additive manufacturing offers. This applies to all 3D printing technologies, the two examples below are for FDM in ducts.

ULA Environmental Control System (ECS) duct: As reported in a prior blog post, United Launch Alliance (ULA) leveraged FDM technology to manufacture an ECS duct and reduce the overall assembly from 140 parts to only 16, while reducing production costs by 57%. The ECS ducts distribute temperature and humidity controlled air onto sensitive avionics equipment during launch and need to withstand strong vibrations. The first Atlas V with these ducts is expected to launch in 2016.

ULA's Kyle Whitlow demonstrates the ECS duct that was printed using FDM
ULA’s Kyle Whitlow demonstrates the ECS duct that was printed using FDM

Orbis Flying Eye Hospital aircraft duct: The Flying Eye Hospital is an amazing concept from Orbis, who use a refurbished DC-10 plane to deliver eye care around the world. The plane actually houses all the surgical rooms to conduct operations and also has educational classrooms. The refurbishment posed a particular challenge when it came to air conditioning: a duct had to transfer air over a rigid barrier while maintaining the volume. Due to the required geometric complexity, the team selected FDM and ULTEM to manufacture this duct, and installed it and met with FAA approval. The story is described in more detail in this video.

FDM used to enable a complex duct connection on an Orbis DC-10 aircraft
FDM used to enable a complex duct connection on an Orbis DC-10 aircraft

Supply Complexity: 3D printing has a significant role to play in retro-fitting of components on legacy aircraft. The challenge with maintaining these aircrafts is that often the original manufacturer either no longer is in business or makes the parts.

Airbus Safety belt holder: Airbus shared an interesting case of a safety belt holder that had to be retrofitted for the A310 aircraft. The original supplier made these 30 years ago and since went out of business and rebuilding the molds would cost thousands of dollars and be time-consuming. Airbus decided to use FDM to print these safety belt holders as described in this video. They took a mere 2 hours to design the part from existing drawings, and had the actual part printed and ready for evaluation within a week!

Airbus used FDM to print safety belt holders for A310 aircraft when the original supplier went out of business
Airbus used FDM to print safety belt holders for A310 aircraft when the original supplier went out of business

Incidentally, the US Air Force has also recognized this as a critical opportunity to drive down costs and reduce the downtime spent by aircrafts awaiting parts, as indicated by a recent research grant they are funding to enable them to leverage 3D printing for the purpose of improving the availability of parts that are difficult and/or expensive to procure. As of 2014, The Department of Defense (DOD) reported that they have maintenance crews supporting a staggering 31,900 combat vehicles, 239 ships and 16,900 aircraft – and identified 3D printing as a key factor in improving parts availability for these crews.

Cost & Lead-time Reduction: In low-volume, high-value industries such as aerospace, 3D printing has a very strong proposition to make as a technology that will bring products to market faster and cheaper. What is often a surprise is the levels of reduction that can be obtained with 3D printing, as borne out by the three examples below.

Airbus A350 Electric wire covers: The Airbus A350 has several hundred plastic covers that are 3D printed with FDM. These covers are used for housing electric wires at junction boxes. Airbus claims it took 70% less time to make these parts, and the manufacturing costs plunged 80%. See this video for more information.

Airbus used FDM to manufacture wire covers for their A350 aircraft
Airbus used FDM to manufacture wire covers for their A350 aircraft

Kelly Manufacturing Toroid housing: Kelly Manufacturing selected FDM to manufacture toroid housings that are assembled into their M3500 instrument, which is a “turn and bank” indicator which provides the pilot information regarding the rate of aircraft turn. These housings were previously made of urethane castings and required manual sanding to remove artifacts from the casting process, and also had high costs and lead times associated with tooling. Using FDM, they were able to eliminate the need to do sanding and reduced the lead time 93% and also reduced per-piece costs by 5% while eliminating the large tooling costs. See the official case study from Stratasys here.

Kelly MFG housing FDM
Toroid housings manufactured for Kelly Manufacturing using FDM for significant cost savings and lead time reduction

These examples help demonstrate that 3D printing parts can be a cost savings solution and almost always results in significant lead time reduction – both of vital interest in the increasingly competitive aerospace industry. Further, design freedom offered by 3D printing allows manufacturing geometries that are otherwise impossible or cost prohibitive to make using other processes, and also have enormous benefit in overcoming roadblocks in the supply chain. At the same time, not every part on an aircraft is a suitable candidate for 3D printing. As we have just seen, selection criteria involve the readily quantifiable metrics of part cost and lead time, but also involve less tangible factors such as supply chain complexity, and the design benefits available to additive manufacturing. An additional factor not explicitly mentioned in any of the previous examples is the criticality of the part to the flight and the safety of the crew and passengers on board. All these factors need to be taken into consideration when determining the suitability of the part for 3D printing.

Arizona Chief Science Officers Design Their Own 3D Printed Name Badges

az-scitech-cso-badges-3d-printed-0The Chief Science Officer program is a program for 6th-12th grade students to represent their school in STEM. And what better way is there for them to identify themselves then with 3D Printed name badges?  The program’s sponsors, the AZ SciTech Festival offer a training retreat for the kids who get elected as their school’s CSO and we all thought introducing design and 3D Printing would be a great activity.

As part of the 2015 Fall CSO Institute, PADT’s Jeff Nichols joined local designer and artist John Drury to spend some time with the kids explaining how to work with logos and shapes to convey an idea, and how to design for 3D Printing.  The kids worked out their own design and sent it to PADT for printing.

We converted their sketch into a 3D Model, starting in Adobe Illustrator. The sketch was traced with vector geometry and then a generic name was added. This was then copied 144 times and each name was typed in, with a few extras. This step was the only boring part.

az-scitech-cso-badges-3d-printed-6

The design worked great because it is a simple extrusion with no need for support material.    The outline of their names were exported as DXF from Illustrator and then imported onto the 3D Model and extruded up to make a solid model of a badge. This was then copied to make a badge for each student. Then the names were imported and extruded on the patterned badges.

az-scitech-cso-badges-3d-printed-5
The was a simple extrusion for each feature, allowing for contrast and readability but keeping things simple.
az-scitech-cso-badges-3d-printed-4
This project was a great opportunity to use both patterns and importing 2D drawings. By laying everything out in a grid, we only had to make one badge and copy that. Then import the names and extrude those on the patterned badges.

STL files were then made and sent off to one of our Stratasys FDM 3D Printers. The FDM (Fused Deposition Modeling) process extrudes an ABS plastic filament, and you can change material during the build. So, to add a bit of contrast, we changed the filament color after the base of the design was done, making the logo and student names stand out.  The final results came out really nice.

az-scitech-cso-badges-3d-printed-1
This is what they look like right out of the machine. We swapped out two color for each build. With some clever packing, we were able to get 12 badges on each platform.
az-scitech-cso-badges-3d-printed-2
The final products really stand out.

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This project was a lot of fun because we were able to work with the students. They got what John and Jeff taught them and did a great job.  We know they will be placed with pride on back backs and jackets across Arizona.

To learn more about the CSO program, visit their website: http://chiefscienceofficers.org/ Check out the blog.  Some of these kids can really write well and their insight into Science, Technology, Math, and Education is insightful.

Real World 3D Printing: PADT Helps ULA Save with Stratasys Digital Manufacturing

Every once in a while a customer hits a home run with Additive Manufacturing, and United Launch Alliance had done that with their application of Stratasys technology to the production of flight-ready components for their rockets.  They were able to leverage 3D printing to take one component from 140 parts to 16, reducing the risks associated with creating the assembly, the piece part costs, and the assembly cost. And PADT is proud to say we were partners in this effort with ULA and Stratasys.

If you are not familiar with ULA, they are the worlds premier launch service company in the US.  It is a joint venture of Boeing and Lockheed that launches the majority of military and civilian payloads that are sent in to space. True "rocket scientists" who are headquartered down the street from PADT's Littleton Colorado office.  They just released a ton of information on how they are using the Stratasys devices they acquired through PADT as an example of what the technology can achieve. 

Here is a picture from Stratasys of one of ULA's structural engineers, Kyle Whitflow, holding an ECS duct they created on the Stratasys Fortus 900mc they purchased through PADT: 

Stratasys just released a great video on how ULA is using the technology. This is a great example of the right people, using the right technology, in the right way:

You can also read the official press release here

We are highlighting his application as a way to let people know that 3D Printing is not just about makers, nor is it just about engineering prototypes. Every day users are creating production hardware to produce usable parts that save them time and money.  Ducts for rockets are a perfect use of the technology because they are complex, low volume, and can make single parts that need to be made in multiple pieces using traditional methods.   This application also highlights the power of the material choices available to users of Stratasys FDM technology.  ULA is using ULTEM 9085 for these ducts because it is durable, lightweight, and can stand up to the heat of the launch event. 

Those of you familiar with the process will notice the dots on the duct. Those are target dots for 3D scanning. ULA took the technology one step further and scan the completed hardware to make sure the manufactured part is within specifications. 

environmental-control-system-duct

The team at ULA has been a pleasure to work with.  They saw the promise of Additive Manufacturing but dealt with it like the seasoned professionals that they are. They started by making engineering prototypes, then as they got a feel for the technology they switched to the production of tooling for manufacturing.  They have now developed the confidence needed to move to flight hardware.  In addition to supplying the machines, PADT consulted with ULA early on, touring their manufacturing facilities to better understand their needs and taking them to see how others are using FDM for manufacturing.  We were fortunate enough to even be invited to attend the launch of their Orion spacecraft from Florida as their guest.  

We are very excited about the additional uses ULA and other companies will develop in the near future for Additive Manufacturing.

 If you want to know more, or would like to have PADT help you in the same way we assisted ULA, please reach out or email info@padtinc.com.

Press Release: Faster 3D Printing Support Removal of Wider Range of Materials with PADT’s New SCA-1200HT

IMG_7411We are very excited to announce that at the end of 2014 PADT shipped the first lot of our new Support Cleaning Apparatus, or SCA.  After almost 6 years of great service, the SCA1200-HT replaces the SCA-1200. The new system is a redesign based upon the 6,700 plus systems that PADT manufactured and supported around the world.  The biggest change to users is broader preset temperature range, allowing users to now remove support from their Nylon and Polycarbonate parts.  The motor and pump are a custom PADT design with better performance and durability. The control and ergonomic interface have also been modified for greater ease of use.

IMG_7507

If you are not familiar with PADT's SCAs and their use, they are accessories for the Stratasys line of Fused Deposition Modeling (FDM) additive manufacturing systems, commonly referred to as 3D Printers.  These systems extrude the build material and a water soluble support material that holds up any overhanging geometry.  The soluble material can be removed with gentle agitation in a slightly basic solution of warm water. We designed the SCA's as the easiest to use and fasted way to remove the support material.

Selling and supporting our own product has been a great experience for our team. Since the company was founded in 1994, we have been designing, simulating, and supporting our customer's products. With the SCA line we are able to practice what we preach on our own product. We have especially enjoyed supporting the products in Europe and Asia, allowing us to get to know the Stratasys Channel overseas as well as customers.

You can read more about the SCA-1200HT on our redesigned website: www.SupportRemoval.com. Here are a couple of videos that show how the system works and how to use it.  The official press release can be found here

 

You can also read the press release with more details below.  Contact your Stratasys supplier for more information.

IMG_7475

 

Press Release:

Faster 3D Printing Support Removal of

Wider Range of Materials  with PADT’s New SCA-1200HT

PADT ships a new generation of their popular Support Cleaning Apparatus product used to remove soluble supports from 3D Printed parts created using Stratasys Fused Deposition Modeling systems.  

 

Tempe, AZ – January 20, 2015 – Phoenix Analysis & Design Technologies, Inc. (PADT, Inc.), the Southwest’s largest provider of simulation, product development, and rapid prototyping services and products, is pleased to announce the release by Stratasys, Ltd. (SSYS) of the new SCA-1200HT support removal system. This new system is designed, manufactured, and supported by PADT and sold exclusively by Stratasys, Ltd for use with their Mojo, uPrint, Dimension, and Fortus Additive Manufacturing systems, also known as 3D Printers.   

The SCA-1200HT is an improved design based on the successful SCA-1200 that has been in use around the world since 2008. The new system features four preset temperature levels for use with a wider range of materials including polycarbonate and nylon. It also includes a proprietary custom pump with longer life, simpler repair and maintenance, and an overall lower operating noise level.  The controls, lid, and parts basket have been ergonomically redesigned while the internal systems have been simplified and made easier to replace by the user or local support provider.

Rey Chu, co-owner of PADT and the person behind the SCA line of products said “With over 6,700 of our previous systems in the field, we gathered a wealth of knowledge on performance and reliability. We used that knowledge to design a system that cleans parts faster, is easier to maintain, and gives a much better user experience.  The hands-off support removal provided by Stratasys’ Soluble Support Technology and PADT’s SCA is a huge advantage to people who use FDM technology for their 3D Printing.  With the SCA-1200HT that advantage just got larger.”

Once parts are printed, users simply remove them from their Stratasys system, place them in the SCA-1200HT, set a cleaning time and temperature, and then walk away.  The device gently agitates the 3D Printed parts in the heated cleaning solution, effortlessly dissolving away all of the support material.  This process is more efficient and friendly than other additive manufacturing systems using messy powders or support material that must be manually removed.

More information on the system as well as a video showing how the SCA-1200HT works is available at www.supportremoval.com.  Those interested in acquiring an SCA-1200HT should contact their local Stratasys reseller.

Phoenix Analysis and Design Technologies, Inc. (PADT) is an engineering service company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and Rapid Prototyping products and services. PADT’s worldwide reputation for technical excellence and an 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 75 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, its Littleton, Colorado office, Albuquerque, New Mexico office, and Murray, Utah office, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com

Stratasys Platinum Partner Status Achieved by PADT

  Stratasys_PLAT_Partner_2015

A lot is going on in the various sales groups at PADT after having such a strong 2014.   We are very pleased to announce that the latest result of outstanding efforts across the board is PADT's new status as a Stratasys Platinum Commercial Partner. Stratasys, Ltd (SSYS), the leading provider of Additive Manufacturing (3D Printing) systems, designates only the best of their reseller channel as Platinum Partners. To obtain this highest level, PADT not only had to meet aggressive sales goals, we also had to make significant investments in resources and people.  In 2014 we exceeded those sales goals by 25% and we opened up a fourth sales and support office, located just south of Salt Lake City in Murray, Utah. 

Here is a pixture of our Additive Manufacturing Sales Manager, Mario Vargas, with one of PADT's principals, Ward Rand, pointing out our latest addition to our "wall o' awards."

  PADT-Stratasys-Platinum-Partner-Award-2015

You can read more about this on our press release here.

PADT has been selling Stratasys equipment for over a decade, and we have been using their systems for over fifteen years.  We have seen them go from a few basic systems to a full offering of solutions from desktop hobby solutions to full production manufacturing centers. This year the team was able to help more customers find the right Additive Manufacturing system for their specific needs. In fact, many of the systems we sold in 2015 were additional machines or upgrades to current machines, showing strong customer satisfaction with Stratasys solutions. 

connex3_with_cmy_helmets     400mc_solo  

We could never have achieved last years success and Platinum status without a fantastic team. Our sales professionals, application engineers, field service engineers, and support staff all strive to provide the highly technical win-win sales experience that PADT has become known for. They truly believe in this technology and are truly enthusiastic about finding new and better ways for our customers to apply it.

Those customers also deserve a heartfelt thank you for being such a pleasure to work with.  Every day we get to interact with the full spectrum of users, from the preverbal garage startup to major aerospace corporations; and everything between.  They teach us something new every day and we are always proud of the value that Stratasys and PADT are able to deliver to their product development efforts. 

If you want to learn more about 3D Printing and why Stratasys systems have continued to outsell the closest competitors for years, please contact Kathryn Pesta at 480.813.4884 or kathryn.pesta@padtinc.com.  She will put you in touch with one of our sales people located in your local area.  Or you can visit www.padtinc.com/stratasys to learn more about the technology. 

 

Seminar Info: Designing and Simulating Products for 3D Printing

Note: We have scheduled an encore Lunch & Learn and companion Webinar for March 23, 2015.  Please register here to attend in person at CEI in Phoenix or here to attend via the web.

ds43dp-1People are interested in how to better do design and simulation for products they manufacture using 3D Printing.  When the AZ Tech council let us know they had a cancelation for their monthly manufacturing Lunch and Learn, we figured why not do something on this topic, a few people might show up. We had over 105 people register, so we had to close registration. In the end around 95 total people made it to the seminar, which is more than expected so we had to add chairs. Who would have thought that many people would come for such a nerdy topic?.

For an hour and fifteen minutes they sat and listned to us talk about the ins and outs of using this growing technology to make end use parts.  Here is a copy of the PowerPoint as a PDF.

We did add one bullet item in the design suggestions area based on a question. Someone pointed out that the machine instructions, what the AM machine uses to make the parts, should be a controlled document. They are exactly right and that is a very important process that needs to be put in place to get traceability and repeatability.  

Here are some useful links:

As always, do not hesitate to contact us for more information or with any questions.

If you missed this presentation, don't worry, we are looking to schedule a live/web version of this talk with some enhancements sometime in March.  Watch the usual channels for time, place, and registration information. We will also be publishing detailed blog posts on many of the topics covered today, diving deeper into areas of interest.

Thank you to the AZ Tech Council, ASU SkySong, and everyone that attended for making this our best attended non-web seminar ever.

Design and Simulation for 3D Printing Full House

3D Printing to Combat Deflategate

3d-printed-footballIn honor of the big game this weekend the folks at Stratasys scored big time with a 3D printed footballStratasys has had a history of using 3D printing to improve on a variety of sports; however this time they out did themselves by possibly solving the infamous issue of deflategate. Since the Ideal Gas Law doesn't exactly explain it, maybe 3D printing could help prevent it from interfering in the big game until an answer is found. I’m not sure the NFL will be too keen on using these balls but it’s a thought

super-bowl-3d-printed-football

The football was created on the Objet500 Connex3 Color Multi-Material 3D Production System and was printed in three materials.  VeroMagenta and VeroYellow was used for the bulk of the design however they were also able to replicate the true texture and feel of a real football using the rubber-like TangoPlus material and all in one print job.  It is heavier than a game ball but can still be tossed around.  Of course they wouldn’t print a football and not test it.  Check out their video below. 

Bonus Link – Here is a fun Brady Deflategate Inaction Figure from Shapeways. 

PADT Opens Utah Office

PADT-UtahIt is now official: PADT has an office in the Salt Lake City area, second after the class A office space in Austin, TX.  Last week we signed a lease for a space at 5282 S Commerce Dr in Murray, Utah.  We have been looking for a while and when this location opened up we felt it was located in a great spot and was the size we needed.  It is 17 minutes from downtown Salt Lake City, less than 30 minutes to most of our SLC customers, and not a bad drive to those who are north and south, right up or down I-15.

This office will focus on providing sales and technical support to our Utah Stratasys and ANSYS customers.  It will provide enough space for a few demo 3D Printers and also has a great meeting room for training and mentoring sessions.

You can read more in the official press release here.  

To get a feel for where it is located, here is a screen grab.

        PADT-Utah-Office-Map

Proximity to some of the best skiing in the country was not much of a factor in the decision process… but it helped.

Here is a shot of Anthony, Doug, Patrick, and Mario modeling in the hallway. 

PADT-Utah-Team-Halway

It will take us a month or so to get everything up and running, but once done we will set up a time for an open house. Watch this space for more about our continued growth and success in Utah.

3D Printed Quill Pen for GISHWHES 2014 Scavenger Hunt

quill-pen-2Sometimes you get strange messages on Facebook.  This weekend I heard a beep and checked my phone “Can you 3D Print a Quill Pen?”  Most messages involve asking me why I posted something stupid or annoying, so this one caught my attention.  Turns out my friend Chelsea is taking part in the 2014 “GREATEST INTERNATIONAL SCAVENGER HUNT THE WORLD HAS EVER SEEN” or GISHWHES.  One of the items in the scavenger hunt is to print out an ink quill pen on a 3D Printer and write “We need to buy more Toner” on a sheet of paper with the pen.  

I can’t resist a challenge like that, so I told her no problem.  And it worked like a charm. 

The process we used was very straightforward:

First I went into a CAD program, SolidEdge in this case, and build a solid model of a quill pen.  Not being quill pen designer I found some web sites on how to cut a pen tip from a real feather, and tried to mimic the resulting geometry:

Quill-Cad-Model Pen-Tip-Quill-Pen
We then wrote an STL file out and sent that to our RP team.  They read that into our preparation software and separated the feathers from the stem, designating a rubber like material for the feather area for artistic purposes, and a hard white plastic for the stem and the tip.

That file was then sent to our Stratasys Objet500 Connex3 and printed in about 30 minutes.  

This video shows the printing process:

Once it was done, we just needed to wash out the support material and it was ready to go.

The moment of truth was then here.  Our intreped Scavenger Hunter took out her handy-dandy pot of India Ink and dipped the quill in, the she wrote out the requested message:
quill-pen-2

I worked like a charm, our handwriting was the biggest issue.

Wanting to see if it enhanced my artistic skills, I used it to sketch the following masterpiece:
quill-pen-face

This is why I use CAD systems.

Here is an image of the final part. The tip is stained black from the ink.
quill-pen-4

All and all a fun project, and I guess the team gets 80 points for doing this task, so we were glad to help.

You can learn more about 3D Printing by visiting here. Our contact us for more information on 3D Printing, Simulation, or Rapid Prototyping.