Additive Manufacturing

The Additive Manufacturing section of this blog is for PADT customers in particular, and users of 3D Printing in general.  We hope you find it useful and entertaining.

Over time we will post information below. Feel free to use the search to find specific information.  We also have some non-changing information on our resource page.


 

PADT Triples 3D Printing Capacity with New Large Stereolithography System

Posted on October 25, 2017, by: Eric Miller

The addition of a new UnionTech RSPro 450 further establishes PADT as the leader in Additive Manufacturing technology in the Southwestern US. With a build volume of 17.7 x 17.7 x 15.75 inches, this state of the art Stereolithography(SLA) machine will triple the company’s capacity to 3D Print with SLA technology. It not only allows the printing of larger parts, it can also create multiple smaller parts in less time.  It will join PADT’s two existing SLA machines along with the Fused Deposition Modeling (FDM), PolyJet, and Selective Laser Sintering (SLS) solutions currently producing parts daily for their customers across the country. “When we started the company in 1994, one of our first purchases was an SLA machine.  It started our 3D Printing services business, and the technology is still heavily used today.” Said Rey Chu, a co-owner of PADT and the leader for PADT’s Advanced Manufacturing efforts.  “This new system gives us added capacity in size, speed, and material choices. We looked at a wide range of SLA systems and felt that UnionTech provided the quality and robustness we need to keep our customers happy.” The new system was delivered the second week of October and will be calibrated and producing customer parts by the end of the month.  One of the advantages of the machine is the easy setup and strong calibration capabilities.  The team will be able to produce parts that are about 75% larger than they can currently.  The additional volume and speed will allow for three times as many parts to be printed in a given week than is possible with the current two smaller and older machines.  Initially, a new rigid ABS-like material will be used that produces very strong and precise parts with white plastic.  PADT’s existing pre- and post-processing tools will be applied to this process with little change.

The UnionTech RSPRO 450 SLA System

UnionTech systems are the most popular machines for SLA Additive Manufacturing outside of the United States. They have proven to be reliable, easy-to-use, accurate, and fast.  They are also an open system, allowing users to use any SLA compatible resin that can usually be acquired at a more affordable price than proprietary material solutions. Stereolithography is the oldest commercial 3D Printing process. It uses photo-curable liquid resins to build parts one layer at a time.  A vat in the machine is filled with liquid material, and a plate is placed just under the surface. Then an ultraviolet laser draws on the very top layer of the liquid, and all of wherever the laser traces, the liquid turns to a solid.  The plate is lowered, a new layer of liquid is spread on top, and the laser creates a new layer. The process repeats until the part or parts are made. The UnionTech machine is a refined and proven application of this technology that was a perfect match for PADT’s current needs.  Also, the company itself was great to work with, and the local sales and support team have been outstanding.  As the team learns the system, they are finding it to be easy to use as well as simple to maintain and calibrate.  The initial quality of parts has been outstanding.

PADT’s 3D Printing Services

PADT has been the Southwest’s leading provider of 3D Printing services since the company was started over 23 years ago.  The company has survived industry consolidation and a vastly changing landscape by focusing on providing high-quality 3D Printed parts to customers using Fused Deposition Modeling, Polyjet Printing, Selective Laser Sintering, and Stereolithography systems combined with one of the most experienced and knowledgeable teams in the Additive Manufacturing space. Located in the ASU Research Park in Tempe, Arizona, PADT’s advanced manufacturing facility currently features ten machines dedicated to printing parts for customers.  The lab includes a full machine shop, part finishing facilities, and an advanced scanning and inspection capability. This added capability is yet another reason why so many companies large and small count on PADT for their 3D Printing needs. Contact us today to learn more about our 3D Printing Services or:  

PADT Partners with 3D Printing Disruptor Carbon to Offer Production Part Manufacturing to the Southwest

Posted on October 23, 2017, by: Eric Miller

The long-term promise of 3D Printing has always been using the technology to replace traditional manufacturing as a way to make production parts.  The various technologies that are considered Additive Manufacturing have been fantastic for prototyping and making tools that are used to manufacturing end-use parts, but rarely work well for production.  Carbon is literally turning the 3D printing world upside down by introducing real production capabilities with their systems. And now that PADT has joined Carbon’s Production Partner Program, on-demand manufacturing using 3D Printing is now a reality in the Southwestern US. The Production Partner program establishes vetted service providers with 3D Printing and manufacturing experience as manufacturing centers. This allows customers who are early adopters of CARBON’s exciting technology, to find a trusted source for their production parts.  PADT was chosen to participate because of our twenty-plus years of experience as a 3D Printing service provider and more than $5,000,000 in injection molding projects, along with in-house product development, scanning, simulation, and inspection. PADT will be adding three Carbon M2 printers to our existing 3D Printing facility at our main office in the ASU Research Park in Tempe, Arizona. The first two machines will be available for production in early 2018, and the third machine will be online by early summer.  Customers will then be able to order production quality parts in volume and receive them within a week. PADT’s investment and this partnership make the dream of On Demand manufacturing of complex plastic components a reality. “We have been looking for a low volume plastic manufacturing solution that uses 3D Printing for some time.” Said Rey Chu, co-owner of PADT “Since we started the company we have been providing soft tooling and rapid injection molding.  Once we saw the Carbon DLS technology in action, we knew we found our solution.  The part quality and material properties are as close to injection molded as we have ever seen.”

About Carbon’s Disruptive Technology

Carbon has introduced a revolutionary way to 3D Print plastic components called Digital Light Synthesis, or DLS.  It combines their proprietary continuous printing technology with programmable liquid resins to create parts with the same strength and surface finish of injection molded parts.  The part creation is fast because it is a continuous process, whereas most 3D Printing machines build up one layer at a time with pauses in-between.  This continuous process is not only fast, but it also avoids the stair-steps created with layered methods. This results in textured surfaces and a surface finish that no other process can approach. https://youtu.be/23at9QglAm8 Programmable materials are the other technology that enables production quality parts.  This unique approach joins two liquid resins as the build material; one that hardens with light and the other with heat. The 3D Printer creates the desired geometry of the part by using light to shape the first material. Then a second step uses an oven to harden the heat activated resin, resulting in engineering-grade mechanical properties.  Moreover, since the strength comes from a heat cured resin, the properties are the same in every direction. Most 3D Printed parts that use a layered approach are weaker in the build direction.  The other significant advantage of including heat activated resins is that they offer a much broader material selection than light activated resins.

PADT’s On-Demand Manufacturing Service

In the past, when PADT’s customers needed parts manufactured with production quality, surface finish, and strength we had to use soft tooling or low-volume injection molding. Both are expensive and take time to make tools.  3D printing is leveraged to make those tools faster, but it still takes time and labor. Production manufacturing could benefit from going directly from a computer model to a finished part, as we do with prototyping.  When we first saw an early Carbon sample part we knew that this was a technology we needed to watch.  As the technology matured further, it became obvious that this was the process PADT was looking for – this was the type of end-use part our customers were requesting.  Then, when the Production Partner program was introduced, we knew we needed to take part. Our On-Demand Manufacturing service will be built around the Carbon Digital Light Synthesis process. Initially, we will use three Carbon M2 systems, a cleaning station, and a curing oven.  This will be placed in the middle of our existing advanced manufacturing facility, allowing us to add machining, hand finishing, painting, and other post-processing steps into each production process as needed. What sets PADT’s offering apart from other providers of production manufacturing with 3D Printing is that we also provide full product development, simulation, and part scanning services to help customers make sure their designs are correct. Before parts are made, we can use our simulation and design knowledge to make sure everything is correct before production begins. And when the parts are completed, we can use our advanced scanning to inspect and our product development testing to verify performance.  By adapting our proven quality to this new technology, we can ensure that every step is done correctly and traceability exists.

Next Steps

You do not have to wait till our production line is up and running.  We can start working with customers now on getting their parts ready for manufacturing with Carbon’s breakthrough Digital Light Synthesis. Our experienced staff can evaluate your components and find the best fit, recommend design changes, and work with Carbon to produce samples. And when our line is up, you can hit the ground running and obtain your parts on-demand, when you need them. Take part in the transition of manufacturing to faster, better, and on demand by contacting PADT today to learn more.

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What we Learned at the Geomagic Conference about Design X and Control X

Posted on September 21, 2017, by: James Barker

On September 11th and 12th Mario Vargas (Hardware Manager for PADT Inc.) and I (James Barker, Application Engineer for PADT Inc.) attended Convergence 2017 in Los Angeles, CA.  This event is held by 3D Systems and is the America’s Software Partner Meeting.  Many strategic partners were in attendance from all across the USA, Canada, and Latin America.  We were able to learn about some new enhancements to Geomagic that will help you with Inspection or Reverse Engineering BIG time!  The first day of meetings we heard from Vyomesh Joshi (CEO of 3D Systems referred to as VJ).  He mentioned that 3D Systems has committed 17% to R&D and after going to this event it is apparent!  VJ briefly talked about each of their software options.  The 1st being Control X and how Polyworks currently has the edge for inspection software but after this next software release, he and other 3D Systems employees seemed confident that they could surpass Polyworks.  The 2nd software he talked about was Freeform which allows users to freely design parts by using a haptic device.  This software would be great for creating custom shapes on a whim.  If you haven’t tried a haptic device, you need to!  It will blow your mind as a designer with the freedom you get by using the haptic device and this Freeform Software.  The 3rd software he talked about was Cimatron which aids in the design of mold and die design.  Of the top 10 largest USA mold makers, 7 of them use Cimatron Software.  The 4th software is something new that will be released later this month.  I would love to tell you more about it but can’t….  sorry! A little about why Mario and I attended this convention, PADT Inc. offers 3D Scanning as both a service and also as hardware or software you can buy.  We use both Geomagic Design X and Geomagic Control X and have experts that are scanning parts for customers for either inspection results or for reverse engineering purposes at our Tempe, AZ office.  The scanner that we use is a CMM quality scanner from Zeiss.  This scanner is capable of scanning 5 million points per scan!  We also offer 3D Systems Capture and Capture Mini scanners which are great tools for reverse engineering.  Each time they scan a part they are capturing about 1 million points per scan.  I am located in the Salt Lake City, Utah office and have a Capture Mini scanner that anyone wanting to see and demo, can come look at and evaluate at our office.  Same holds true for the Capture scanner and Zeiss scanner in our Tempe, AZ Headquarters.  Since we offer these services, we love knowing what new tools are available with these product releases. Jumping back to the conference, on September 12th, there were breakout sessions.  We chose to go to the Geomagic Design X session to see what enhancements have been made.  This software is the preferred software in all of the industry for reverse engineering parts.  There were many different vendors/partners in the room we were at.  There was even a rep from Faro who prefers to sell Geomagic Design X software with each Faro Arm that he sells because this software is so powerful.  The neat thing about this software is all of the improvements that have been made to it.  If you are accustomed to designing parts with Solidworks, Solidedge, NX, Catia, Pro-E or any of the other CAD software, you will be able to use this software with ease.  Every command that you execute within Design X is editable just like the major CAD software.  You have the ability to create sketches on planes or to make life even easier, there are wizards that automatically create sketches and perform a command like an extrusion or revolve that is editable after completing the wizard.  After you have finished reverse engineering your parts within Design X, you can live transfer your new CAD data over to the above-mentioned CAD software.  Once you have imported this data into NX or Solidworks, you can again edit any of the sketches that were created within Design X but now in your software of choice!  I would love to show you how powerful this software is.  There is a reason why it is the preferred reverse engineering software in the industry. Geomagic Control X session was next.  It also happened to be the last session of the day.  To be honest, I have only used Design X so I was looking forward to learning more about this software.  From all the demo’s that I have seen in the past from this software, it appeared really hard to use.  That is all changing with this new software release and is the reason why VJ is confident that it will compete and could exceed Polyworks as the preferred software for inspection.  The biggest thing that stuck out to me was the ability to set up a workflow for scanned data for inspection so that you can create your inspection reports.  The idea is that if you have a part that needs to be inspected for quality, you 3D scan the part and then import the CAD file.  By overlaying the scanned data over the CAD data you can show the deviation within the 2 parts and you are able to have different views in a 3D PDF to share with others the actual quality of the part.  As you are assigning your GD&T to this first inspection file, you are creating the first steps of the workflow.  There are many options for the workflow that you can create and 3D Systems has made it easy to create the workflow.  I feel that the power of this software is when you can open up the results of the first inspection report and do a split screen on your monitor to show the 100th or 1,000th part side by side and see how that part deviates from the first. I had a great time in California at this event even though all of our time was spent at the hotel.  The streets looked nice from the window on the 11th floor.  Maybe next time we will venture out!  If anyone from 3D Systems is reading this, let’s go out to eat next time instead of eating at the hotel for breakfast, lunch, and dinner!  Although the view from the dining room was nice! If you have any questions about 3D scanning whether it is for Inspection or for Reverse Engineering, let us know at PADT Inc.  We look forward to helping you.

Standard Roof Rack Fairing Mount Getting In Your Way?! Engineer it better and 3D Print it!

Posted on September 19, 2017, by: Nathan Huber

It is no mystery that I love my Subaru. I bought it with the intention of using it and I have continually made modifications with a focus on functionality. When I bought my roof crossbars in order to mount ski and/or bike racks, I quickly realized I needed to get a fairing in order to reduce drag and wind noise. The fairing functions as designed, and looks great as well. However, when I went to install my bike rack, I noticed that the fairing mount was in the way of mounting at the tower. As a result, I had to mount the rack inboard of the tower by a few inches. This mounting position had a few negative results:
  • The bike was slightly harder to load/unload
  • The additional distance from the tower resulted in additional crossbar flex and bike movement
  • Additional interference between bikes when two racks are installed
These issues could all be solved if the fairing mount was simply inboard a few more inches. If only I had access to the resources to make such a concept a reality.... oh wait, PADT has all the capabilities needed to take this from concept to reality, what a happy coincidence! First, we used our in-house ZEISS Comet L3D scanner to get a digital version of the standard left fairing mount bracket. The original bracket is coated with Talcum powder to aid in the scanning process. The output from the scanning software is a faceted model in *.STL format. I imported this faceted CAD into ANSYS SpaceClaim in order to use it as a template to create editable CAD geometry to use as a basis to create my revised design. The standard mounting bracket is an injection molded part and is hollow with the exception of a couple of ribs. I made sure to capture all this geometry to carry forward into my redesigned parts, which would make the move to scaled manufacturing of this design easy. Continuing in ANSYS SpaceClaim, as it is a direct modeling software instead of traditional feature-based modeling, I was able to split the bracket's two function ends, the crossbar end and fairing end, and offset them by 4.5 inches, in order to allow the bike rack to mount right at the crossbar tower. I used the geometry from the center section CAD to create my offset structure. A mirrored version allows both the driver and passenger side fairing mount to be moved inboard to enable mounting of two bike racks in optimal positions. The next step is to turn my CAD geometry back into faceted *.STL format for printing, which can be done directly within ANSYS SpaceClaim.   After the design has been completed, I spoke with our 3D printing group to discuss what technology and material would be good for these brackets, as the parts will be installed on the car during the Colorado summer and winter. For this application, we decided on our in-house Selective Laser Sintering (SLS) SINTERSTATION 2500 PLUS and glass filled nylon material. As this process uses a powder bed when building the parts, no support is needed for overhanging geometry, so the part can be built fully featured. Find out more about the 3D printing technologies available at PADT here. Finally, it was time to see the results. The new fairing mount offset brackets installed just like the factory pieces, but allowed the installation of the bike rack right at the tower, reducing the movement that was present when mounted inboard, as well as making it easier to load and unload bikes!! I am very happy with the end result. The new parts assembled perfectly, just as the factory pieces did, and I have increased the functionality of my vehicle yet again. Stay tuned for some additional work featuring these brackets, and I'm sure the next thing I find that can be engineered better! You can find the files on GrabCAD here.  

How to Simplify Aircraft Certification – Stratasys Webinar

Posted on September 12, 2017, by: Trevor Rubinoff

The aerospace industry's adoption of additive manufacturing is growing and predicted to revolutionize the manufacturing process. However, to meet stringent FAA and EASA requirements, AM-developed aerospace products must be certified that they can achieve the robust performance levels provided by traditional manufacturing methods. Current certification processes are complex and variable, and thus obstruct AM adoption in aerospace. Thanks to a newly released aerospace package released by Stratasys for their Fortus 900mc printer and ULTEM 9085 resin, Aerospace Organizations are now able to simplify the aviation certification process for their manufactured parts. Join PADT's 3D Printing General Manager, Norman Stucker for a live webinar that will introduce you to the new Stratasys aerospace package that removes the complexity from FAA and EASA certification. By attending this webinar, you will learn:
  • How Stratasys can help get more parts certified for flight quicker and easier.
  • The benefits of Aerospace Organizations using the Fortus 900mc and ULTEM 9085 resin
  • And much more!

Don't miss your chance to attend this upcoming event, click below to secure your spot today!

  If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT). You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you're good to go!

Quick Tips for Stratasys’ new Nylon 12CF Material

Posted on September 8, 2017, by: James Barker

One of the newest materials available for the Stratasys Fortus 450 users (other machines could have this capability at a later date) is the Nylon 12CF. Nylon 12CF is a Carbon Fiber filled Nylon 12 filament thermoplastic. The carbon fiber is chopped fibers that are 150 microns long. This is Stratasys’ highest strength and stiffness to weight ratio for any of their materials to date as shown below.  Often times, when Stratasys is getting close to releasing a new material, they will allow certain users to be a beta test site. One beta user was Ashley Guy who is the owner of Utah Trikes, which is located in Payson, Utah. He is having so much success with this material that he is making production parts with it. Watch this video to hear more from Ashley and to see some of his 3D printed parts. Talking with Ashley, he has helped us with understanding some of the tips and tricks to get better results from printing with this material. One change that he highly recommends is to adjust the air gap between raster’s to -.004”. This will force more material between the raster’s so there won’t be as many noticeable air gaps. Here is a visual representation of the air gap difference using Stratasys software Insight: The end goal at Utah Trikes is to produce production parts with this material, so by adjusting the air gap, the appearance of the parts look close to injection mold quality after the parts have been run through a tumbler. Some key things that I really like about this material is that the support material is soluble and easily removed using PADT’s own support cleaning apparatus (SCA Tank) that aid with the support removal. After the support has been removed, they are placed in a tumbling machine to smooth the surfaces of the part with different media within the tumbling machine. Any post process drilling or installing of helicoil inserts or adding bushings to the part is done manually. Jerry Feldmiller of Orbital ATK, who also did a beta test of this material at his site in Chandler, Arizona, mentions these 3 tips:
  1. Nylon12 CF defaults to “Use model material for Support”. 90% of the time I uncheck this option.
  2. I use stabilizing walls and large thin parts to anchor the part to the build sheet and prevent peal up.
  3. Use seam control set to Align to Nearest.
Jerry also supplied his Nylon 12CF Tensile Test that he performed for this new material as shown below. He mentions that the Tensile Strength is 8-15 ksi depending on X-Y orientation. ~5 ksi in Z-axis, slightly lower than expected. This part is used to clamp a rubber tube which replace the old ball valve design at ATK. Ball valves are easily contaminated and have to be replaced. After two design iterations, the tool is functioning. Jerry also follows a guide that Stratasys offers for running this material. If you would like a copy of this guide, please email me your info and I will send it to you. My email is James.barker@padtinc.com Now onto Stratasys and the pointers that they have for this material. First, make sure the orientation of the part is built in its strongest orientation. Nylon materials have the best layer-to-layer bond when comparing them against the other thermoplastics that Stratasys offers. Whenever you print with the Nylon materials (Nylon 6, 12, and 12CF), it is advised to print the sacrificial tower so that any loose strands of material are collected in the sacrificial tower instead of being seen on the 3D printed part. You also want to make sure that these materials are all stored in a cool and dry area. Moisture is the filaments worst enemy, so by storing the material properly, this will help tremendously with quality builds. It is also recommended for parts larger than 3 inches in height to swap the support material for model material when possible. Since the support material has a different shrink factor than the model material, it is advised to print with model material where permitted. This will also speed your build time up as the machine will not have to switch back and forth between model and support material. We have seen some customers shave 5+ hours off 20 hour builds by doing this. This best practice paper is the quick tips and tricks for this Nylon 12CF material from our users of this material. The Stratasys guide goes into a little more detail on other recommendations when printing with this material that I would like to email to you. Please email me with your info. Let us know if this material is of interest to you and if you would like us to print a sample part for testing purposes.

Press Release: PADT and Stratasys Announce Lockheed Martin Additive Manufacturing Laboratory at Metropolitan State University in Denver

Posted on August 29, 2017, by: Eric Miller

PADT-Press-Release-IconPADT and Stratasys have worked with Lockheed Martin to establish a new Additive Manufacturing Laboratory at Metropolitan State University in downtown Denver.  The Lockheed Martin Additive Manufacturing Laboratory is the first-of-its-kind facility in Colorado. It is focused on giving students and industry access to the equipment and faculty needed to develop the next generation of manufacturing tooling, based on the use of 3D printing to make the tooling. This is PADT's third successful contribution to the creation of Academia + Industry + Equipment Manufacturer lab, the others being at ASU Polytechnic focused on characterization of 3D Printed parts and at Mesa Community College, focused on training the needed technicians and engineers for running and maintaining additive manufacturing systems. These types of efforts show the commitment from Stratasys, industrial partners, and PADT to making sure that the academic side of new manufacturing technology is being addressed and is working with industry. We reported on the grand opening of the facility here,and are very pleased to be able to announce the official partnership for the Laboratory.  Great partners make all the difference. Official copies of the press release can be found in HTML and PDF.

Press Release:

PADT and Stratasys Announce First-of-its-Kind Additive Manufacturing Lab in Colorado, Located at Metropolitan State University of Denver

Lockheed Martin Additive Manufacturing Laboratory helps students and engineers spur design and creation of composite tooling applications to reduce manufacturing lead times and streamline costs

TEMPE, Ariz. and Minneapolis, MN - August 28, 2017 ─ Phoenix Analysis and Design Technologies (PADT) today announced the company is teaming with Stratasys Ltd. (Nasdaq: SSYS), a global leader in applied additive technology solutions, to unveil a first-of-its-kind additive manufacturing lab in Colorado - located at the Metropolitan State University of Denver. Expected to open later this fall, the Lockheed Martin Additive Manufacturing Laboratory is unique to the state, dedicated to advance use of 3D printing for creation of composite tooling applications addressing complex design and manufacturing requirements. Empowering next-generation manufacturing, 3D printing allows designers and engineers to improve efficiency and lead times while minimizing costs. At the centerpiece of this lab are additive technology solutions from Stratasys, enabling students and engineers to speed production and streamline efficiencies with 3D printed, custom tooling solutions addressing even the most complex designs and shapes.  Backed by the Stratasys Fortus 900mc Production 3D Printer, the environment is funded through a grant from Lockheed Martin Space Systems – and now becomes one of the few located in Colorado and the only one at a higher-education institution in the Rocky Mountain region. Building the Lockheed Martin Additive Manufacturing Laboratory at MSU Denver is a major development in the progression of additive manufacturing tooling applications,” said Rey Chu, Principal and Co-Founder, Manufacturing Technologies at PADT, Inc.The expertise and dedication of Stratasys and PADT - combined with the generosity of Lockheed Martin and vision for advanced workforce development from MSU Denver - will help propel our industry far beyond where it is today. “We’re excited to work with Lockheed Martin to propel creation of highly innovative, additive manufacturing curriculum at MSU Denver. Both students and local businesses now have access to leading 3D printing solutions for development of composite structures – enabling manufacturers to save time, money, and solve even their most unique design challenges,” said Tim Schniepp, Director of Composite Solutions at Stratasys. “We have no doubt the lab will quickly become a cornerstone of additive manufacturing innovation across the State of Colorado.”  Initially deployed at MSU Denver, the additive manufacturing curriculum will later become available for use by other academic institutions across the country. Additionally, PADT will work with MSU Denver, Lockheed Martin and other users to build a Fortus 900mc Users Group within the Rocky Mountain region. Supporting Quotes Brian Kaplun, Manager, Additive Manufacturing at Lockheed Martin Space Systems: “Lockheed Martin believes this first-of-its-kind laboratory at MSU Denver can shape the future of space. We’ve built 3D-printed parts that traveled 1.7 billion miles to Jupiter, and we look forward to developing a workforce that understands how to use this technology for future flight hardware, tooling and other advanced manufacturing applications.” Robert Park, Director, Advanced Manufacturing Sciences Institute at Metro State University of Denver: “MSU Denver is fortunate to have such great partners who support our passion for nurturing young minds to shape the future of the additive manufacturing industry. We’re also excited to work with Stratasys and PADT on progressing the industry beyond its current scope.” 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 3D Printing 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 www.PADTINC.com. About Lockheed Martin Space Systems Headquartered in Bethesda, Maryland, Lockheed Martin is a global security and aerospace company that employs approximately 97,000 people worldwide and is principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. About Metropolitan State University of Denver MSU Denver is a leader in educating Coloradans through university programs particularly relevant to the state's economy and the demands of today's employers. With the highest number of ethnically diverse students among the state's four-year colleges, MSU Denver offers 67 bachelor and five master degrees in accounting, business, health administration, teaching and social work. Nearly 20,000 students are currently enrolled at MSU Denver, and 75 percent of the University's 88,000 graduates have remained in Colorado as valuable members of the state's workforce. More information can be found at www.msudenver.edu. About Stratasys Stratasys (NASDAQ: SSYS) is a global leader in applied additive technology solutions for industries including Aerospace, Automotive, Healthcare, Consumer Products and Education. For nearly 30 years, a deep and ongoing focus on customers’ business requirements has fueled purposeful innovations—1,200 granted and pending additive technology patents to date—that create new value across product lifecycle processes, from design prototypes to manufacturing tools and final production parts. The Stratasys 3D printing ecosystem of solutions and expertise—advanced materials; software with voxel level control; precise, repeatable and reliable FDM and PolyJet 3D printers; application-based expert services; on-demand parts and industry-defining partnerships—works to ensure seamless integration into each customer’s evolving workflow. Fulfilling the real-world potential of additive, Stratasys delivers breakthrough industry-specific applications that accelerate business processes, optimize value chains and drive business performance improvements for thousands of future-ready leaders around the world. Corporate Headquarters: Minneapolis, Minnesota and Rehovot, Israel. Online at: www.stratasys.com  http://blog.stratasys.com and LinkedIn. Stratasys, Fortus, and FDM are registered trademarks, and the Stratasys signet is a trademark of Stratasys Ltd. and or its subsidiaries or affiliates. All other trademarks belong to their respective owners.

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PADT Media Contact Alec RobertsonTechTHiNQ on behalf of PADT 585.281.6399 alec.robertson@techthinq.com PADT Contact Eric Miller PADT, Inc. Principal & Co-Owner 480.813.4884 eric.miller@padtinc.com Stratasys Media Contact Craig Librett Stratasys Principal & Co-Owner 518.424.2497 craig.librett@stratasys.com
 

Introducing the Stratasys J750 – Webinar

Posted on August 7, 2017, by: Trevor Rubinoff

Introducing the Stratasys J750 - Webinar

August 30th, 2017 - 11:00 AM - 12:00 PM MST

The Stratasys J750 3D printer delivers unavailed aesthetic performance including true, full-color capability with the texture mapping and color gradients. Create prototypes that look, feel and operate like finished products, without the need for painting or assembly, thanks to the Stratasys J750's wide range of material properties.

With this, students can easily experience both the prototyping and testing stages of the manufacturing process, helping to prepare them for what they will experience once they enter the workforce. The high quality materials available with the J750 also allow for the creation of highly intricate and realistic models, perfect for helping medical students with research.

The wide color spectrum, combined with the fine-finish, multi-material capability, let's the Stratasys J750 produce parts with an incredible array of characteristics. Prototypes that need to look, feel and function like future products are possible in a single print operation, with minimal to no finishing steps, like painting, sanding or assembly. With such an innovative machine comes a variety of user applications, such as:
  • Image Rapid Prototyping
  • Concept Models
  • Medical Models
  • Jigs & Fixtures
  • Colored Textures
Join PADT's Sales executive Jeff Nichols and 3D Printing Application Engineer James Barker from 11:00 AM - 12:00 PM MST AZ for an in depth look at how the Stratasys J750 stacks up against it's competition, and how it's various attributes help to make it the perfect fit for institutions such as yours!   Don't miss this unique opportunity to bring the future of manufacturing into your classroom or workplace, secure your spot today!
  

DustRam: A Great Example of Using 3D Printing for Durable Production Parts

Posted on August 3, 2017, by: Eric Miller

Nothing makes us happier here at PADT than seeing a customer be successful with technology we worked with them on. When Jack King of DustRam came to us for a prototype for a part on his dust free tile removal product it was just the start of a fantastic journey that showed off the power of 3D Printing.  After a few iterations Jack was able to replace his expensive and long lead metal mouthpiece with a plastic one that he could manufacture on demand in his own shop using his Stratasys 3D Printer. It was such a great story that two publications were interested and wrote far better writeups than I could. The first is interesting because it is an industry trade magazine for people in the floor installation business. Their perspective is refreshing for those of us who live in the engineering world, getting more into the practical application of the product:

http://digital.bnpmedia.com/publication/?i=422744#{"issue_id":422744,"page":52}

This was preceded by a fantastic article in Additive Manufacturing magazine that gets more into the technical side:

http://www.additivemanufacturing.media/articles/3d-printed-device-proves-rugged-enough-for-dust-free-tile-removal-

If you want to learn more about how you can use additive manufacturing to produce yout production hardware, contact us today.  

Webinar: Additive Manufacturing & Simulation Driven Design, A Competitive Edge in Aerospace

Posted on July 27, 2017, by: Eric Miller

PADT recently hosted the Aerospace & Defence Form, Arizona Chapter for a talk and a tour. The talk was on "Additive Manufacturing & Simulation Driven Design, A Competitive Edge in Aerospace" and it was very well received.  So well in fact, that we decided it would be good to go ahead and record it and share it. So here it is: Aerospace engineering has changed in the past decades and the tools and process that are used need to change as well. In this presentation we talk about how Simulation and 3D Printing can be used across the product development process to gain a competitive advantage.  In this webinar PADT shares our experience in apply both critical technologies to aerospace. We talk about what has changed in the industry and why Simulation and Additive Manufacturing are so important to meeting the new challenges. We then go through five trends in each industry and keys to being successful with each trend.
If you are looking to implement 3D Printing (Additive Manufacturing) or any type of simulation for Aerospace, please contact us (info@padtinc.com) so we can work to understand your needs and help you find the right solutions.  

Installing a Metal 3D Printer: Part 5 (Housekeeping)

Posted on July 27, 2017, by: Dhruv Bhate, PhD

Download all 5 parts of this series as a single PDF here.

This is my final post in our 5 part series discussing things we learned installing a metal 3D printer (specifically, a laser powder bed fusion machine). If you haven't already done so, please read the previous posts using the links below. If you prefer, you can register for a webinar to be held on July 26, 2017 @ 2pm EDT (US) where I will be summarizing all 5 parts of this blog series. Register by clicking on the image below: Housekeeping may seem too minor a thing to dedicate a post to, but when it comes to metal 3D printing, this is arguably the single most important thing to do on a regular basis once the equipment, facilities, safety and environmental considerations are addressed up front. In this post, I list some of the activities specific to our Concept Laser MLab Cusing R machine that we do on a routine basis as indicative of the kinds of things that one needs to set aside time to do, in order to maintain a safe working environment. In this post, I break down the housekeeping into the 3D printer, the wet separator and the filter change.

1. The 3D Printer

All 3D printers need to be routinely cleaned, but for powder based metal 3D printers, this needs to be done after every build. Three steps need to be performed during cleaning of the printer:
  • Powder Retrieval: After the build, the powder is either still in the dose/feed chamber or not. All powder that is not in the dose chamber needs to be brushed to the overflow chamber for recycling. While it is possible to vacuum this powder, that is not recommended since it results in greater loss of powder and also increases the burden on cleaning the vacuum and creating wet waste.
  • Process Chamber Cleaning: The process chamber after a build gets covered with fine combustion particles (soot) that need to be wiped away, as shown in Figure 1. The recommendation is to do this cleaning using lint-free or clean room wipes moistened with an ammonia based cleaner like Windex Original.
  • Lens Cleaning: Special lens cleaning wipes are to be used to clean the protective lens that separates the chamber from the laser. Standard lens cleaning wipes can be used for this, in a gentle single-pass movement.
It is important to wear appropriate PPE and also NOT contaminate the lens. Improper or irregular cleaning will result in soot particles interfering in subsequent builds. Soot particles can occasionally seen in subsequent builds especially when the inert gas and the ventilator (circulating fan) are turned on - this is more likely to happen if the chamber is not routinely and properly cleaned.
Figure 1. Post-build cleaning of the 3D printer and required materials

2. Wet Separator

The wet separator (vacuum) sucks up stray powder and suspends it in a water column. The metal particles will descend to the bottom of the water column (as shown in Figure 2) and need to be routinely cleaned out. This cleaning procedure is recommended daily for reactive metals - failing this, the metal particles will weld themselves to the metal container and prove to be very difficult to scrape out. For non-reactive metals, a daily flush may be excessive (since this will add to the cost in terms of labor and disposal) and a weekly routine may be preferable for a wet separator that serves 1-2 machines. To reduce the water needed to flush out the powder sludge at the bottom, a standard pump sprayer is very effective. Further reduction in water usage and disposal can be achieved by a filtration device such as the one developed by the folks at Kinetic Filtration.
Figure 2. Cleaning a wet separator
 

3. Filter Change

Filters need to be changed periodically as shown in Figure 3. A video below (set to start at the 2:58 mark) shows how the filter change is performed for our MLab, for a non-reactive metal, so I shall not describe the procedure further. A reactive metal alloy filter needs to be stored in water to passivate it at all times, even through disposal. Other OEMs recommend sand and other materials, so it is important to follow the specific instructions provided by your supplier for passivation.
Figure 3. Removing, passivating and disposing the filter
  https://youtu.be/0wQhXle6VEA?t=2m58s

Summary

Good housekeeping for metal 3D printing is vital and more than just aesthetic - there is a modest chance that failing to follow your supplier's instructions on one or more of the items above will result in a safety incident. This is especially true for reactive alloys, where filter changes are recommended after each build and wet separator clean on a daily basis.

Disclaimers

  • This is intended to supplement the supplier training you must receive before using the equipment and not meant to replace it – in case of conflicting information, your supplier’s training and equipment requirements override any discussion here. PADT and the author assume no legal responsibilities for any decisions or actions taken by the readers of this document.
  • My personal experience derives specifically from the use of Laser-based metal 3D printing tools, specifically Concept Laser’s MLab Cusing R equipment. I expect majority of this information to be of use to users of other laser based powder bed fusion metal systems and to a lesser extent to Electron Beam systems, but have no personal experience to vouch for this.
~

Final Thoughts

This concludes my 5-part post on what we learned installing a metal 3D printer. If you have any thoughts on the content or would like to discuss this subject further, please let me know by messaging me on LinkedIn or by sending an email to info@padtinc.com, citing this blog post. I will be happy to include any suggestions in my posts with due credit. Thank you for reading - I hope this has added value to the discussion on safely and effectively advancing metal 3D printing technology.

Announcement: Affordable Metal 3D Printing from Desktop Metal Added to PADT Portfolio

Posted on July 24, 2017, by: Eric Miller

PADT is pleased to announce that it has partnered with Desktop Metal to resell its office-friendly and affordable metal 3D Printing solution. The partnership will also allow PADT to integrate this exciting new technology into its 3D Printer maintenance and part printing services. Desktop Metal’s new system is unique to the industry because it is a complete solution with a patented anti-sintering material that enables easily removed supports and the creation of complete assemblies. With the proprietary sintering furnace the DM Studio System delivers accurate parts quickly.  PADT will be representing this new solution in Arizona, Colorado, New Mexico, and Utah. “We are very excited to fill this gap in our product offering,” said Rey Chu, co-owner and director of manufacturing technology at PADT. “It enables us to serve customers who need stronger properties than plastic additive manufacturing systems can offer, but who don’t need a direct laser melting solution. We researched our options and watched the development of many different products. We knew Desktop Metal had the right solution when we learned that it had developed a complete package that is easy to use.” The DM Studio System™ is based on the Metal Injection Molding (MIM) process and will start shipping this September. It is the first office-friendly platform for metal 3D printing and is considerably less expensive than existing technology. The Studio System will be sold as a package for $120,000. This includes the metal 3D printer, debinder, and microwave-enhanced sintering furnace. As a leader in additive manufacturing for more than 20 years, PADT is a resource for customers who need 3D Printing as a service, or who need their own systems in-house. The DM Studio System™ will compliment the complete line of Stratasys FDM and Polyjet systems that the PADT resells as well as direct laser melting systems from our partner Concept Laser. Our company’s expertise with fused deposition modeling, sintering, and MIM also make us uniquely qualified to represent this solution. “Our team is looking forward to getting this technology in front of customers,” said PADT’s Manager of Hardware Sales, Mario Vargas. “Metal 3D Printing is something our customers have wanted to add, but they could not find a turn-key solution for prototyping with various metal materials. Desktop Metal leveraged its expertise in metallurgy and software to deliver a complete system that can be run in an office environment. This is very compelling for many of our customers across industries.” In the coming months, PADT will be setting up seminars and contacting customers across the Southwest to help educate the user community on the unique value proposition of the DM Studio System™. Anyone interested in learning more can reach out to info@padtinc.com or call 480.813.4884, technical experts are available to explain and answer any questions.

Save the date!

To show off this exciting technology we will be having putting on a DesktopMetal Studio System Road Show in August. Register now!
To learn more right now you can:

Installing a Metal 3D Printer: Part 4 (Environmental)

Posted on July 20, 2017, by: Dhruv Bhate, PhD

Download all 5 parts of this series as a single PDF here.

What waste streams are generated in powder-based metal 3D printing? Are they hazardous? How should they be disposed responsibly? This is the fourth part of a 5-part series discussing things we learned installing a metal 3D printer (specifically, a laser powder bed fusion machine). If you haven't already done so, please read the previous parts using the links below. If you prefer, you can register for a webinar to be held on July 26 @ 2pm EDT (US) where I will be summarizing all 5 parts of this blog series. Register by clicking on the image below:

1. Sources of Waste

As shown in Figure 1 below, metal powder used in this process ends up in dry and wet waste. The dry waste can be composed of wipes and gloves with powder and soot, and the wet waste is mostly composed of water and suspended metal particles (from the wet separator and ultrasonic cleaner), and for reactive alloys, can also consist of filter cartridges that need to be suspended in water throughout. Because the wastes contain metal powders, we must stop and ask if this is safe for sending to our landfills and into our sewers where there is a risk of contaminating groundwater and creating other long term environmental havoc. Thus, the first question is: are these wastes hazardous?
Fig 1. Powder Life Cycle

2. Is this Waste Hazardous?

There are two sources for this information: the EPA (in the US) and the powder supplier's data sheets. It helps to begin by understanding some definitions - statements in italics are quoted from the EPA, the rest of the text is mine.
  • Waste: "A waste is any solid, liquid, or contained gaseous material that is discarded by being disposed of, burned or incinerated, or recycled"
  • Hazardous Waste: There are several types of hazardous waste and associated definitions of each. The two main categories are:
    • Listed Waste: "Your waste is considered hazardous if it appears on one of four lists published in the Code of Federal Regulations (40 CFR Part 261)." I have looked at this list and to the best of my knowledge, no metal powders of concern to the metal 3D printing process appear on this list (as of July 10, 2017). The metal powders currently used are also not considered acute hazards.
    • Characteristic Waste: In addition to listed wastes, the EPA specifies certain characteristics that a waste may possess (even if not listed) that would make it hazardous. In the context of metal powders, the potentially relevant categories are:
      • "It catches fire under certain conditions. This is known as an ignitable waste".
      • "It is harmful or fatal when ingested or absorbed, or it leaches toxic chemicals into the soil or ground water when disposed of on land. This is known as a toxic waste."
Due to the generality of the definitions of "Characteristic Waste," and the lack of available data in the public domain such as from a TCLP test (Toxicity Characteristic Leaching Procedure), it is hard to dismiss these as not being relevant. For each of our waste streams, consider the arguments below:
  • Dry Waste: We know that given the right conditions and an ignition source, that these powders, especially reactive alloys and combustion products, can ignite.
  • Wet Waste: We also know that while water serves as a passivation for powders, we cannot guarantee that the powder will always stay in wet state if it is not disposed as such. Evaporation, for example, can leave behind combustible powder.
Another source of hazard information is the Safety Data Sheet (SDS) or Material Safety Data Sheet (MSDS). Some metal powders are more hazardous than others, so when planning, consider looking at all the alloys you may possibly be using in the future and ask for SDS sheets on all of them. One example, is of Ti6Al4V powder below, clearly showing significant hazards present.
Fig 2. Sample hazards identification from SDS (shown here for Ti6Al4V)

3. What Regulations do I need to be aware of?

The EPA established three categories of waste generators in their regulations, listed below along with the relevant quantity of waste generated and stored, for our purposes (visit EPA's site for the full list, this is not comprehensive) - EPA cites these numbers in hundreds and thousands of kilograms, hence the strange numbers below (in lbs): Note this is the sum total of all hazardous wastes your site is generating (in our case, dry and wet wastes combined), not a limit per category. Depending on what category you fall in, you will need to follow EPA's regulations, available here. Additionally, some states may have additional regulations and this is where I only have studied this problem for my home state of Arizona, which is in line with the EPA's federal guidelines and does not, to the best of my knowledge, impose additional restrictions. The full list by state is here. If you are a "Very Small Quantity Generator" as we are at PADT, the regulations are fairly straightforward and involve three items (quoted from the EPA's site) - the requirements are more stringent for larger quantities.
  • VSQGs must identify all the hazardous waste generated.
  • VSQGs may not accumulate more than 1,000 kilograms of hazardous waste at any time.
  • VSQGs must ensure that hazardous waste is delivered to a person or facility who is authorized to manage it.
At PADT, we contract with an industrial waste disposal company that picks up and replaces our waste containers. Yes, this adds cost to the process and at least one company has developed a method to significantly reduce wet waste (which tends to be the larger of the two) by employing a filtration device. Similar innovations and a general focus on reducing waste can drive these costs down.

4. Opinion

As with all regulations, one can approach them by focusing on the specificity of the language. While this is important, it is also useful to seek to understand the intent of the regulation. When it comes to these wastes, I ask if I would be comfortable carrying it in my car and disposing of it in my hypothetical backyard landfill (dry waste) or my local water body (wet waste) - and the answer to both, for me, is a NO. So why should I ask my city to do this? This is understandably an exaggerated way of looking at the problem, but I believe at a minimum, serves as a risk-conservative upper-bound that is useful when addressing uncertainty in these matters. You can read the final installment of this series, on housekeeping, here.

5. References

  1. EPA, Hazardous Waste Generators Home Page
  2. EPA, Categories of Waste Generators
  3. EPA e-CFR, Title 40, Part 261
  4. US Environmental Agencies by state 

Disclaimers

  • This is intended to supplement the supplier training you must receive before using the equipment and not meant to replace it – in case of conflicting information, your supplier’s training and equipment requirements override any discussion here.
  • Local, state and federal regulations vary and are important – partner with your local environmental authorities when making decisions
  • My personal experience derives specifically from the use of Laser-based metal 3D printing tools, specifically Concept Laser’s MLab Cusing R equipment. I expect majority of this information to be of use to users of other laser based powder bed fusion metal systems and to a lesser extent to Electron Beam systems, but have no personal experience to vouch for this.
  • PADT and the author assume no legal responsibilities for any decisions or actions taken by the readers of this document or of subsequent information generated from it.

Installing a Metal 3D Printer: Part 3B (Safety Risks – Prevention & Mitigation)

Posted on July 18, 2017, by: Dhruv Bhate, PhD

Download all 5 parts of this series as a single PDF here.

How can you minimize safety risks in powder-based metal 3D printing? This is the second half of my third post in a 5-part series discussing things we learned installing a metal 3D printer (specifically, a laser powder bed fusion machine). If you haven't already done so, please read the previous posts using the links below, in particular, part 3A which is a prequel to this post. I also recommend reading my post on the difference between reactive and non-reactive alloys in the context of this process. In the previous post, I identified four main risks associated with operating a laser-based powder bed fusion metal 3D printer such as the one we use at PADT, a Concept Laser MLab Cusing R. In this post, I address three of these risks in turn and first discuss how the risk can be prevented from manifesting as a hazard (prevention) and then address how it can be mitigated in case it does result in an incident (mitigation). I will deal with the fourth risk (environmental damage) in the next post. As with the previous post, my intent is to inform someone who is considering getting a metal 3D printer and not be comprehensive in addressing all safety aspects - the full list of disclaimers is at the end of this post. If you prefer, you can register for a webinar to be held on July 26 @ 2pm EDT (US) where I will be summarizing all 5 parts of this blog series. Register by clicking on the image below:

Risk 1: Fire and Explosion

1.1 Prevention:

Fig 1. ESD wrist-strap
The key to preventing a fire is to remember that it needs three things ("the fire triangle"): fuel (metal powder or soot), an ignition source (laser or spark) and oxygen. While certified equipment is designed to operate in a safe manner when bringing the laser and the metal powder in contact by doing so in an inert gas environment, you as the operator, are responsible for avoiding any ignition sources when handling powder or soot outside of the inert environment. This is because two of the three aspects have been met: fuel (powder or soot) and oxygen (in the ambient). As long as basic risks are eliminated (sparking equipment, smoking etc.), the primary risk that remains is Electro Static Discharge (ESD) and thus the main piece of preventive equipment is an ESD wrist-strap, as shown in Figure 1, or equivalent ESD management methods. It helps to appreciate the life cycle of the powder, as it goes from purchased jar to ending up returned as recycled powder (the majority of the powder), or in the wet or dry waste streams. This is shown in Figure 2. While this looks quite complex, coming out of the machine, the powder and soot only have 4 streams that you have to follow: the powder trapped in the part, the powder that you will recycle, the soot and powder trapped in the filter and finally, what will be cleaned with wipes and accumulate on gloves. While this is not comprehensive (internal hoses and shafts can also accumulate powder), these are the ones operators will deal with on a regular basis.
Fig 2. Metal powder life-cycle

1.2 Mitigation:

In addition to doing everything we can to prevent fire, we also need to be prepared in case it does happen. There are (at least) four aspects that need to be considered, dealt with in turn below: 1.2.1 Personal Protective Equipment (PPE)
Fig 3. Extended PPE
PPE is your self-defense in case of a fire and it is thus a critical element of the safety procedures you need to pay attention to and remember. Tasks are of varying risks, and our supplier recommends PPE for this process in three categories:
  • Protective Clothing: A lab-coat that covers your arms, protective gloves, ESD strap if working with reactive metals
  • Standard PPE: Respirator, nitrile gloves, face mask (if not integrated with respirator), ESD strap
  • Extended PPE: Standard PPE PLUS fire-rated bunny suit, fire-rated gloves (see Figure 3)
Below is a list of all activities that involve some risk of ignition (or inhalation, to be discussed in the next section) and the associated level of PPE recommended.
Table 1. PPE recommendations for different tasks (Courtesy: Concept Laser, Inc.)
PPE can be tricky to implement consistently since as seen above, there are several tasks of varying risk levels that require different PPE. The conservative approach is to prepare for the worst case and wear Extended PPE at all times, but this can make you uncomfortable for long periods of time, reduce your mobility for some tasks, and introduce human error. Instead, here is the 3-step logic I use for remembering what to wear:
  • Always wear gloves, goggles and protective clothing (lab-coat) when you work with the machine - make this a rule even for the simplest of tasks like using the keyboard and mouse
  • If you are directly handling (i.e. not through a glove box) virgin or recycled non-reactive metal alloy powder (i.e. no reactive powders or combustion products), standard PPE is adequate
  • For everything else, you need extended PPE
1.2.2 Fire Extinguishing
Fig 4. Class D Fire Extinguisher (must be mounted or on a trolley, NOT as shown here on the floor)
There are several recommendations for how to manage fire extinguishing. This is an area where you need to get your fire marshal to weigh in. What is clear is that water and CO2 are not safe choices for metal fires [NFPA 484 6.3.3.5(1)]. For extinguishing fires, the consensus is to use Class D fire extinguishers, such as the one shown in Figure 4. The fire extinguisher needs to be a Class D since this is the one rated for metal fires. The main training aspect is to ensure it is pointed down at the base of the fire rather than at it, followed by sweeping. What to do with Water Sprinklers?: Water can be dangerous for metal fires, but the risk of not having any sprinklers may outweigh the risk of water exacerbating the fire. This is a function of how much risk you are introducing (amount of powder, proximity to other flammable sources, area surrounding the printer etc.) and is a decision best made together with your fire marshal. 1.2.3 Powder Storage
Fig 5. Flammables Cabinet
Powder storage will involve powder in unopened jars, opened jars as well as in the overflow collector which is on the machine. It is best to store opened and unopened jars in a flammable cabinet as shown in the adjacent figure. This is not essential for non-reactive alloys, but necessary for reactive metal alloys. For large quantities of reactive alloys, blast proof walls may be necessary - this is again something your city officials and fire marshal can guide you on, but do not neglect the importance of getting their buy-in early. Finally, most cities will require you to fill in some paperwork and show on a plan (map) where you are storing your powders, and what their composition is. This is to help inform the fire-fighters that there are metal powders onsite, and where they are located, in case of a building fire. If you do plan on working with reactive alloys in particular, you must involve your fire marshal sooner rather than later.  

Risk 2: Powder Inhalation and Contact

2.1 Prevention

The main method of minimizing risk of powder inhalation is through the use of a respirator. These come in many forms, but the two most recommended ones for this process are respirators with built-in face-masks (as shown in Figure 3), and more preferable, the PAPR respirator, which delivers a positive pressure of air (for more information, read OSHA's guide on respirators). N95 and higher respirator filters are recommended, though N100 are ideal. Contact with powder is avoided by wearing gloves at all times when handling the machine. It is also useful to minimize risk of carrying powder outside the metal 3D printer area:
  • Before starting work, put away watches, wrist jewelry and cell phones.
  • Once done with the work, take off your protective coat and wash your hands and arms up to elbows before handling anything else.
  • Consider installing an adhesive floor mat for you to step on as you walk out of the room.

2.2 Mitigation

Fig 7. SDS binder
What to do in case of exposure is typically documented in the SDS (Safety Data Sheets), which is specific to the material in question, as shown in Figure 6 below. Ensure you have an SDS from your powder supplier for all powders you order, and collect them in a folder that is stored close to the entrance for easy retrieval, as shown in Figure 7.
Fig 6. Example of SDS information on responding to exposure
 

Risk 3: Inert Gas Asphyxiation

3.1 Prevention

Fig 7. O2 Sensor
Inert gas (Nitrogen or Argon) is used for every build and is either stored in cylinders (argon) or piped from a generator (Nitrogen). Proper, leak-free facilities setup and equipment performance is essential, as is following recommended supplier maintenance on the equipment itself. An inability to drop to required oxygen PPM levels in the build chamber, or large fluctuations in maintaining them may be associated with a leak and should be addressed with the supplier before proceeding. Users of the equipment must know where the shut-off valves for the gases are, in case they need to turn it off for any reason.

3.2 Mitigation

The main mitigation device is an Oxygen sensor such as the one in Figure 7. This is an important sensor to have especially in confined spaces around any equipment that relies on inert gases, including the 3D printer and furnace. If oxygen levels fall below safe values, an alarm is triggered and immediate evacuation is required.

4. References

  1. National Fire Protection Association’s standard for combustible metals, NFPA 484
  2. OSHA on Oxygen Deficiency
  3. OSHA’s Guidance on Dust Explosions
  4. OSHA Respirator guide
  5. J.M. Benson, “Safety considerations when handling metal powders,” Southern African Institute of Mining and Metallurgy, 2012
  6. R. G. Goldich, “Fundamentals of Particle Technology,” Chapter 15, Midland IT and Publishing, UK, 2002

Disclaimers

  • This is intended to supplement the supplier training you must receive before using the equipment and not meant to replace it – in case of conflicting information, your supplier’s training and equipment requirements override any discussion here. PADT and the author assume no legal responsibilities for any decisions or actions taken by the readers of this document.
  • My personal experience derives specifically from the use of Laser-based metal 3D printing tools, specifically Concept Laser’s MLab Cusing R equipment. I expect majority of this information to be of use to users of other laser based powder bed fusion metal systems and to a lesser extent to Electron Beam systems, but have no personal experience to vouch for this.
  • Local, state and federal regulations vary, and are important – partner with your local fire marshal (or equivalent authority) as a starting point and take them along with you every step of the way. If in the US, familiarize yourself in particular with OSHA’s guidance on dust explosions and NFPA 484, the National Fire Protection Association’s standard for combustible metals (links above).
~ Any other tips or ideas I have not covered, please let me know by messaging me on LinkedIn or by sending an email to info@padtinc.com, citing this blog post. I will be happy to include them in this post with due credit. My aim is only to add to the discussion, not be the last word on it - and I look forward to suggestions that can make operating this technology safer for all of us and the ones that rely on us coming home every day. Please find the 4th part of the series here.
PADT Open House 2017, image courtesy James Barker

Towards Self-Supporting Design for Additive Manufacturing: Part 1 (Standard Guidelines)

Posted on July 12, 2017, by: Jeannie Kozicki

1. Background:

When it comes to Additive Manufacturing (AM), there is a lot to consider before hitting the print button. One of the biggest constraints in most AM processes is the need for supports for overhangs, which are aspects of the design that will not print properly without supports either due to the force of gravity acting on the material (natural free-falling state of the material with no support forcing it into position), or the thermomechanical effects associated with printing with no underlying thermally conductive and warpage-constraining material. The solution is to either redesign any of the problem areas or reorient the whole piece to avoid any overhangs that need these supports. During my internship at PADT Inc., I will be focusing on strategies to minimize the need for supports, towards the ideal goal of manufacturing only self-supporting structures, because it’s never a bad idea to decrease waste, both in terms of additional material used and the labor involved in removing the support materials after the print. This post (part 1) of this blog series is going to be about evaluating the most basic guidelines of printing a self-supporting structure to extract some insight.

2. Methodology:

Using inspiration from some machine accuracy tests found online, I designed my own prints to evaluate the Makerbot Replicator 5th generation’s ability to print overhangs using angles, upright holes, bridges, arched bridges, and 90 degree overhangs—and I present each one of these standard guidelines below. My process parameters for almost all of the tests with, of course, supports OFF were as follows:
  • Extruder Temp: 212 C
  • Travel Speed: 70 mm/s
  • Infill Density: 10%
  • Layer Height: 0.20 mm
  • Number of Shells: 2
   

3. Observations:

3.1 Angles For testing overhangs with angles, I printed out two different sets of trapezoids. The first was a set of six ranging from 25-75 degrees (or 65-15 degrees from the leveled plane).

  

   

As shown by the photos above, the prints were of good quality and only started to show visibly poor quality on the 65 and 75 degree samples. The thinnest edge on the 65 degree sample curled up due to the heat of the extruder. The same issues were present on the 75 degree piece, but this is more exaggerated because of how harsh the angle is.

  

My hope of printing self-supporting pieces was shattered when I printed out an 85 degree trapezoid. To save material, I only printed out a section of the trapezoid, but the angled edge did not print smoothly at all. Not only that, but it did not print at a true 85 degree angle. With these tests, it is safe to say that a machine can handle up to a 65 degree angle with light finishing needed, but further experimentation can be done to see if these angles can be improved.

3.2 Upright Holes

   

For these, I did 2 quick tests. The first was printed with the settings listed above, and the second was printed with only one shell (contour). The numbers next to the circles (1, 2, 4, 6, 8, 10) represent the radii in millimeters. The double-shelled print came out a lot better than the single-shell replica on the edges of the piece, but the single-shelled piece had slightly cleaner holes due to less weight on the overhang. However, both pieces had defects that can easily be sanded down. 3.3 “H” Overhangs/Bridges

  

Bridges are sometimes referred to as an “H” overhang due to the overhang having two sides to support it. When testing bridges with 90 degree overhangs of 0.25, 0.75, 1.25, 1.75, and 2.25 inches, the results showed increasing stringing with length for all but the 0.25 inch sample.

3.4 Arched Bridges

  

The inspiration for these came from the shape of an egg. That’s because I learned during an egg drop lab that an egg is stronger when weight is being put on it length-wise than if the sides are pinched. As expected, the pieces where the curves are less steep (like an egg laying so the shorter distance is perpendicular to the ground) have more defects, and the steepest curve (as if the top of an egg was the mold for this piece) was almost perfect. The wider the curve becomes, the less it can support itself and the more the piece is unrecoverable. 3.5 “T” Overhangs/Cantilevers

  

The final test for this section is the “T” overhang, which only has a support on one side. This happened to be the only test that completely failed, as none of these pieces are usable - it’s safe to say that pieces should not be made without supports on both side of the overhang.

4. Insight

A rule-of-thumb “overhang rule” used in the industry is that a piece can be self-supporting as long as the overhang does not exceed the angle to the horizontal by more than 45 degrees. A back-of-the-envelope (literally) calculation shows that if we approximate an angular edge with stair-steps of thickness t, the overhang length l equals t/tan(Θ). According to this equation, this means that to increase the allowable angle, the layer thickness can be increased or the unsupported length should be reduced. This observation is confirmed by a previous investigation into the angles of self-support for ULTEM-9085 on Stratasys Fortus systems showed how the maximum angle that can be self-supported is indeed a function of layer thickness, but also a function of the contour width (see graph below). In the graph, the lower the angle, the lesser the support needed, since everything above that angle will need to be supported. Thus, thicker layers result in lesser support. Due to the nature of contouring in the FDM processes, a thin contour that forms the edge of the overhang is likely to droop off. But as it gets thicker, it maintains greater contact with the supported portion. The fact that thicker layers and contour widths may yield larger support angles is counter intuitive since we generally assume thinner layers improve print quality - and this is in general true. But if the aim is to design parts without supports, both these variables can push the limits of the process.

5. Conclusions

Basic design guidelines for overhangs can be, to a first order, simplified to one design rule: the angle below which material needs to be supported. This angle in turn, for the Fused Deposition Modeling process on a given machine and material, can be optimized by manipulating layer thickness and contour width. In my next post, I will look for inspiration for self-supporting strategies from other disciplines. Stay tuned.