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

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.

 

Distributed ANSYS 18.1 with the SP-5 Benchmark using an INTEL 1.6TB NVMe

I recently had a chance to run a series of benchmarks on one of our latest CUBE numerical simulation workstations. I was amazed by the impressive benchmark numbers and wanted to share with you the details for the SP-5 benchmark using ANSYS 18.1. Hopefully this information will help you make the best decision the next time you need to upgrade your numerical simulation C Drive from whatever to now is the time to buy a Non-Volitile Memory Express drive. Total speedup using identical CUBE hardware, except for the INTEL DC P3700 NVMe drive @32 Cores is a 1.19x speedup!

  • Time Spent Computing Solution ANSYS SP-5 Benchmark
    • 161.7 seconds vs. 135.6 second
    • ANSYS 17.1 & ANSYS 18.1 Benchmarks

The link below is to a great article that I think will catch you up to speed regarding NVMe, PCIe and SSD Technology.

HDD Magazine hints NVME is coming, I say NVMe is already here…

CUBE w32iP Specifications (July 2017)

  • CUBE Mid-Tower Super Quiet Chassis (900W PS)
  • CPU: 32 INTEL Cores – 2 x INTEL e5-2697A V4 32c@2.6GHz/3.6GHz Turbo
  • OS: INTEL NVMe – 1 x 1.6TB INTEL Enterprise Class SSD
  • Mid-Term Storage: – 1 x 10TB Enterprise Class SATA 6Gbp/s, 256M, Helium sealed
  • RAM: 256GB DDR4-2400MHz LRDIMM RAM
  • GRAPHICS: NVIDIA QUADRO P6000 (24GB GDDR5X RAM)
  • MEDIA: DVD-RW/Audio 7.1 HD
  • Windows 10 Professional

Just how much faster the INTEL NVME drive performs over previously run ANSYS Benchmarks?

Check out the data for yourself:

  1. ANSYS 17.1 – SP-5 Benchmarks
  2. ANSYS Website
  3. HPC Advisory Council
  • ANSYS Benchmark Test Case Information.
  • ANSYS HPC Licensing Packs required for this benchmark
    • I used (2) HPC Packs to unlock all 32 cores.
  • 1.19x Total Speedup!
  • Please contact your local ANSYS Software Sales Representative for more information on purchasing ANSYS HPC Packs. You too may be able to speed up your solve times by unlocking additional compute power!
  • What is a CUBE? For more information regarding our Numerical Simulation workstations and clusters please contact our CUBE Hardware Sales Representative at SALES@PADTINC.COM
    • Designed, tested and configured within your budget. We are happy to help and to  listen to your specific needs.

ANSYS SP-5 Benchmark Details

BGA (V18sp-5)

Analysis Type Static Nonlinear Structural
Number of Degrees of Freedom 6,000,000
Equation Solver Sparse
Matrix Symmetric
 July 2017 TIME SPENT COMPUTING SOLUTION TOTAL CPU TIME FOR MAIN THREAD ELAPSED TIME
CUBE w32iP CUEB w32iP CUBE w32iP
# of Cores CUBE w32iP CUBE w32iP CUBE w32iP
2 1034.3 1073.7 1076
4 594.7 630.3 633
6 431.5 465.7 472
8 333.4 367.9 377
10 268.7 302.6 316
12 243.6 276.5 287
14 223 256.2 264
16 186.8 219.3 227
18 180 212.4 226
20 174.4 207.4 220
22 164.5 197.4 209
24 155.6 188.2 199
26 147.1 179.2 193
28 146.4 178.2 190
30 140.8 168.5 196
31 140.4 164 196
32 135.6 158.1 182
WO/GPU Acceleration WO/GPU Acceleration WO/GPU Acceleration

July 2017, drjm, PADT, Inc.

CUBE W32iP SP-5 Benchmark Graph

CUBE w32iP with INTEL DC P3700 1.6TB

Click Here for more information on the engineering simulation workstations and clusters designed in-house at PADT, Inc.. PADT, Inc. is happy to be a premier re-seller and dealer of Supermicro hardware.

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

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)

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

 

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.

Silicon Desert Insider: Millennials in tech – Turning what makes them different into an advantage

It is an earned privilege for older generations to make fun of younger ones.  And my generation loves to bemoan those damn “Millennials!” with their phones, their laziness, and their sense of entitlement.  But in reality they are just different and good business people know how to make different work for them.  I explore how to take advantage of that in “Millennials in tech: Turning what makes them different into an advantage”  This is our third guest blog post for the Silicon Desert insider portion of the AZ Business Magazine.

Phoenix Business Journal: ​Is ‘cybersecurity’ the Y2K of this generation?

I am sick and tired of cyber security fear mongers hijacking so many technical discussion.  Even meetings on STEM education seem to always devolve into a discussion on CyberSecurity.  The last time this happened to me it reminded me of what it was like back in 1998 and 1999 when IT Consultants were spreading fear in order to charge huge fees to solve problems with the Y2K that many programs had. So I asked the question “​Is ‘cybersecurity’ the Y2K of this generation?” and if the hysteria being spread is actually bad for solving these real and serious problems.

Getting to Know PADT: Support Cleaning Apparatus (SCA) Manufacturing and Support

This is the third installment in our review of all the different products and services PADT offers our customers. As we add more, they will be available here.  As always, if you have any questions don’t hesitate to reach out to info@padtinc.com or give us a call at 1-800-293-PADT.

PADT is in the business of helping people who make products.  So most people think of us as a provider of tools and services.  What they do not know is that PADT actually has a few of its own products.  The most successful of these is our line of Support Cleaning Apparatus systems, abbreviated as SCA.  These devices are used to remove soluble support material from parts 3D printed in Stratasys Fused Deposition Modeling Systems. They are robust machines manufactured and serviced by PADT, but sold through the Stratasys worldwide sales channel. As of July of 2017, over 10,800 units have been delivered to Stratasys.

Optimized Performance for Hands-Off Part Cleaning

The Stratasys 3D Printing systems that use Fused Deposition Modeling extrude plastic through a heated nozzle to build parts one layer at a time.  There are actually two nozzles. One puts down the building material and the other a support material that is dissolved in warm water that is slightly base.  The best way to remove that support material is to put it into a warm bath where the part is gently tumbled so that the water can works its way evenly into the part.  Stratasys tried several solutions for a companion washing system and eventually came to PADT and asked if we would try our hand at building a robust and efficient system.

The result was the SCA-1200.  Launched at the end of 2008 it met the design requirements for reliability, part cleaning time, and noise.  Over 7,000 of these systems were shipped and saw heavy usage. In fact, if you have a Stratasys FDM system there is a good chance you have an SCA-1200.  It contained a unique shower head design that was optimized with simulation, and a modular assembly that could be repaired easily in the field.

Based upon the success and lessons learned from the SCA-1200, we released the SCA-1200HT in 2014.  With the same basic form factor, this design replaced the off-the-shelf magnetically coupled pump with a simpler and more reliable custom design from PADT. The new unit also had a more pleasing visual design, several usability enhancements, and a greater temperature range. It has sold over 3,000 units and continues to be a popular system.  The latest release includes a no-temperature setting that allows it to be used to clean Stratasys Polyjet parts.

The success of both system lead to a request to look at building a larger machine that could clean more parts at one time as well as larger parts.  The SCA 3600 has three times the volume but shares many internal parts with the SCA-1200HT.  Both of the new systems are doing well in the field with even better reliability and faster part cleaning times. They are also simpler to debug and repair.

The SCA systems are sold as stand alone devices or are bundled with key Stratasys FDM machines.  You can learn more about them on our SCA page:  www.padtinc.com/sca or you can contact whoever you buy your Stratasys equipment from.

Here is a video for the SCA-1200HT that talks all about what it does:

Practicing what We Preach

One of the most rewarding aspects of designing and manufacturing the SCA family of products was that it forced us to practice what we preach. We talk to companies every day about using simulation, 3D Printing, design for manufacturing, proper product development processes, and many more things needed to get a product right.  With the SCA we were the customer. We had to Walk the Walk or stop talking the talk.

 

It has been a phenomenal experience that has made us even better at helping our customers produce their new products. We used CFD to optimize the gentle agitation design and shower head and worked closely with our vendors to minimize the cost of manufacturing.  The worst part was that when the schedule slipped, we couldn’t blame the customer (only slightly joking).  One of the best set of lessons came from doing the repair and refurbishment of systems that failed. Even though the failure rate was low, we learned a lot and were able to make improvements to future designs. Now when we sit across from a customer and talk about the design, test, and manufacture of their product, we can really say that we understand where they are coming from.

 

 

 

 

 

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

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)

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.

Video Tips – Two-way connection between Solidworks and ANSYS HFSS

This video will show you how you can set up a two-way connection between Solidworks and ANSYS HFSS so you can modify dimensions as you are iterating through designs from within HFSS itself. This prevents the need for creating several different CAD model iterations within Solidworks and allows a more seamless workflow.  Note that this process also works for the other ANSYS Electromagnetic tools such as ANSYS Maxwell.

Phoenix Business Journal: Why architecture matters

I’m an engineer. If pushed I will tell you that function should dominate design and that spending time and resources on aesthetics or styling is a waste of money. But a little voice in my head would be screaming “No! Wrong!” because there is value in the visual beauty of something. Nowhere is that truer than in architecture

Importing and Splitting Solid Models for ANSYS HFSS 18.0

Importing solid 3D Mechanical CAD (or MCAD) models into ANSYS HFSS has always been and remains to be a fairly simple process. After opening ANSYS Electronics Desktop and creating an HFSS design, from the menu bar, select Modeler > Import. A dialog box will open to navigate to and directly open the model.

The CAD will automatically be translated and loaded into the HFSS 3D Modeler. If the geometry is correct and does not require any editing, the import process is complete and analysis can begin! However, if there are any errors with the geometry, there is excessive or invalid detail, or if it’s not organized into separate bodies conducive for electromagnetic analysis, you may soon realize that the editing capability is limited to scaling, reorienting, or Boolean operations. This approach can be particularly troublesome when portions of the model (or all of the model) which consist of different materials are not split into different objects. For example, notice the outer conductor, inner conductor, and dielectric of the imported SMA below are all one solid object.

Unless you’re lucky enough to work with the creator of the CAD, you will need to find a way to split this model into the inner and outer conductors, and the dielectric. However, since the release of ANSYS R18.1, the power of SpaceClaim Direct Modeler (SCDM) and the MCAD translator will be packaged together. The good news is, the process described above will continue to work. The better news is, SCDM offers new capabilities to directly edit or clean imported geometry. So, here are a few simple steps to quickly split this SMA connector using SCDM. You can download a copy of this model here to follow along. If you need access to SCDM, you can contact us at info@padtinc.com. It’s worth noting, at this point, that the processes discussed throughout this article work the same for HFSS-IE, Q3D, and Maxwell designs as well.

[1] First, after opening ANSYS SpaceClaim, the step file can be imported through the menu File > Open or by simply dragging and dropping the file into the SCDM window. [2] To separate the dielectric from the outer conductor, select Design > Intersect > Split Body. [3] Click and hold the center mouse button to rotate the model so the boundary between the dielectric and outer conductor is visible. Hold the Ctrl key and click the center mouse button to pan, and use the center mouse scroll to zoom in and out. Finally, press ‘z’ on the keyboard to fit the view window. [4] When positioned, click on the object to split (in this case it is the entire model). [5] Then, click on the face which defines the boundary between the dielectric and outer conductor. [6] Finally, press the Esc key. The first split is done!

Repeat the Split Body process to separate the center conductor from the dielectric. Notice under the structure tree that there are now three separate objects.

The split body function is also useful to simplify a structure for analysis. For example, the female side of the SMA could be simplified as a solid center conductor. [1] Reposition the connector to view the female side. [2]-[3] Control the visibility of each body with the object’s checkbox in the structure tree. [4] Measure the length of the female side by pressing the letter ‘e’ on the keyboard and selecting the top edge (note the line length of 2.95mm for later). [5] Then, repeat the Split Body process to split the center conductor at the boundary between the male and female sides. [6]-[7] However, rather than pressing the Esc key, click on the female receiver to automatically remove the body.

[1] To extend the center pin to its original length, select Design > Edit > Pull. [2] Click on the face where the female side was originally attached and select the Up To option. [3] Type in the previously measured length of 2.95mm. [4] Finally, press Enter (press Esc 3x to exit the Pull command).

Repeat the Split Body and Pull processes until the model has been divided into different bodies for each material type and is sufficiently simplified.

Once the model is ready, select File > Save As to save the geometry as the preferred format. Perhaps the most familiar approach to HFSS users would be to save the new model as a STEP file, then to import the model into HFSS as described in the first paragraph.

Phoenix Business Journal: Developing a product in a global market

Everyone has adjusted to the fact that these days products are manufactured and sold globally. What many companies have not accepted, is that fact that the product development process is also global. If you don’t accept that and adjust, your competition will. “Developing a product in a global market” goes over the basics to successfully leveraging global resources to develop new products.

Phoenix Business Journal: Using small amounts of capital to make a big difference with microloans

Ten years ago PADT, deposited $1,000 into an online service called Kiva. Kiva makes small loans to people all around the world.  We just made our 100’th investment, bringing us to $7,900 lent to different businesses in 40 different countries around the world. Take a look at “Using small amounts of capital to make a big difference with microloans” to learn more about how you or your company can make a real difference in people’s lives.

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

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).

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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