Spreading the Word on 3D Printing at 3 Events in 3 States this Month

PADT-Logo-Stained-Glass-Rendering1PADT has been asked to share our expertise in 3D Printing at three different events in the month of September.  We look forward to the opportunity to talk about how additive manufacturing is being used today, and how it can be used in the future.  

September 11, 2014 – Salt Lake City, Utah
Utah Manufacturers Association Summit
We will have a booth and will be participating in the summit, representing the application of additive manufacturing. This informative all-day seminar will teach you about the revolutionary UtahCAN Database and how it can benefit your company, how to utilize social media to your advantage, better handle impacts on your business and leadership strategies to change your workplace.

September 12, 2014 – Albuquerque, New Mexico
TechFiestaABQ2014 TechRev: State of the art and Digital Fabrication
PADT’s very own Jeff Strain will be on the “State of the art and digital fabrication” panel from 9:00 to 10:00. TechRev is a full day conference featuring tracks for technologists, entrepreneurs and the business community produced by the NM Technology Council.

September 18, 2014 – Phoenix, Arizona
SAE Arizona Section September Meeting
PADT co-owner Eric Miller will be giving a presentation on Additive Manufacturing technologies.

We hope to see you at one of these events.  If you would would like PADT to participate as a speaker, panel member, or an exhibitor, please contact us and we will check our schedule. We truly do love talking about this stuff.
Look for even more chances to interact with PADT on 3D Printing in October, during the Arizona Manufacturing Month.

Additive Manufacturing Motor Trends

Additive manufacturing (AM) has been used in the motor sports world for years.  Now more than ever, race teams have found that additive manufactured parts have the quality and durability to meet their demands. From NASCAR to the World Rally Championship, race teams around the world are excited about the possibilities that AM brings to the table. For an interesting webinar on-demand and a great whitepaper, click the image below. 68905-Motor-Trends-Webinar_960x350

3D Thursday – 4th of July Style

I was in search of something Independence Day/3D printing related to celebrate the 4th of July.  It seems like a lot of people had the same idea.  Thomas Jefferson……yup, he was 3D printed at RedEye on Demand.  President Obama was 3D printed at the first ever White House Maker Faire last month.   So, after sifting through replicas of the Statue of Liberty or American Flags, I came across something really cool.  

3D-printed-Ellis-Island-3D-Model-Don-Foley-via-3D-Printing-IndustryDesigner Don Foley  has created a very detailed model of the Ellis Island Customs House which you can download for free for the next 2 weeks.   

His design is in 4 separate sections that can be taken apart to see the beautiful and intricate detail on each of the floors.  It’s a beautiful design of a very important part of American history.

And just for fun, here is an interesting article about the creation of an exact replica of the Liberty Bell using 3D scanning.

Happy 4th of July!

Reblog: Terry Wohlers Predictions at Inside 3D Printing Conference & Expo

If you are interested in 3D Printing and you don’t follow Terry Wohlers, you should. He has been following this industry since it started and he is one of the best at separating hype from reality.

Here is a link to a blog post on 3dprinter.net on his predictions at this years Inside 3D Printing Conference & Expo.

He brings up some very good points on where the technology is being used today and where growth may occur.  Also some thoughts on the global growth of additive manufacturing, and the obstacles and challenges the industry faces. 

My favorite take-away from the posting is Terry’s that “more and more effort is needed to not just take a traditional design and 3D Print it, but rather to re-think the entire part design to take into account the capabilities and limitations of AM.”

3D Color Printing: Stratasys Publishes Nice White Paper on Maximizing Multi-Material and Color 3D Printing

Stratasys just released a nice white paper on the uses of their new color technology in the Objet500 Connex3 system.  This machine is more than just a way to print parts in a variety of colors, it allows you to load three different materials, including colors. 
3D-Color-Printing-Colors-1The paper goes in to some detail on how the technology works, what the advantages are, and offers some use cases where beta testers in industry were able to apply the technology on their projects.  If you are interested in 3D Printing in general, and printing color parts in particular, you should download the white paper.

 3D-Color-Printing-Pressure-Contour-1As always, if you can contact PADT at 480.813.4884 or sales@padtinc.com. Or visit our website.


Wohlers Associates Lists Top 3D Printing News of 2013

Wohlers Associates just blogged their list of the top news stories for 2013 in 3D Printing.  It is worth a read to look beyond the hype we have seen this year and focus on the stories that will be having an impact in the future:


As a Stratasys distributor and provider of additive manufacturing services, PADT can attest to the importance of the stories listed.  The first one, the GE Fuel Nozzle, had an especially significant impact on the world of commercial additive manufacturing, especially with the Aerospace customers we work with.  In many ways, GE’s move was the tipping point for metal additive manufacturing and for companies to really look at AM as an end part manufacturing solution.

2014 is already shaping up to be a big year.  We expect to see consolidation and a weeding out in the consumer and prosumer 3D printer market, better material options across all of the technologies, and more adoption of the technology in new industries and applications.

Wholers Associates has been consulting in additive manufacturing for over 27 years and is PADT’s go-to resource for what is really going on in the AM world.

A Guide to Creating Good STL Files

imageThe STL file is the linqua-franca of the prototyping world, the file format that all geometry creation tools write, and that all prototyping systems read. When you make a prototype it will be an exact copy of your STL file. If your file is not accurate, then your prototype will not be accurate. If there are errors in your file, you may not be able to get a prototype made. Therefore, a little bit of time understanding STL files and how to create a good one is a good investment that will pay off in the long run.

About STL Files

When additive manufacturing was just starting the manufacturers of machines faced a problem – they needed a way to get 3D solid models from a large number of CAD systems to their machines for processing. The common file format for geometry interchange, IGES, was not robust enough because of toleranceing issues. Writing a program to slice up each CAD format was also not practical. So they looked at the problem and realized they did not need exact mathematical models made up of NURB, Bezier, or analytical geometry. The algorithm that sliced up each layer just needed polygons on the surface. So the STL file just needed to have those polygons. And the STL file was born.

Lets talk about that slicing process. If you remember, almost all additive manufacturing processes work by creating stacked layers that are a cross section of the part you want. To build the part you must slice the geometry in software, calculating that cross section. Doing the intersection of a plane with a complex NURB surface is hard math, but the intersection with a triangle is very easy and results in a line segment. This makes creating the path for each layer much easier.

STL stands for STereoLithography, or Standard Tessellation Language, depending on which source you check. It was invented for 3D Systems by the Albert Consulting Group way back in 1987 to support the first Stereolithography machines. The format describes a collection of facets, or polygons. Each polygon is defined by a normal “outward” vector and the vertices that define it. Although the format supports more than three vertices per facet, in practice everyone uses three, defining a triangle. The file can be a text file (ASCII) or a binary file.

Users almost never have to worry about the file because the programs they use to create their geometry automatically generate STL files in the proper format. If you do need to write your own routine to output an STL file, it is fairly simple.


clip_image001 The way an STL file is made is the program that creates the STL file goes through the topology of the model and meshes it:

1: First it puts points on all of the shared edges of all the surfaces
2: Then it creates triangles on each surface

The algorithm used to create the facets varies from program to program, but most of them use the same routines they use to make facets for the 3D graphics you see on your monitor.

There are two things to note about faceting. The first is that each corner must be coincident with at least one other corner. No corners can touch the edge of another triangle. The second is that a triangle is flat and your surface can be curved. To make your curved surface look curved you need enough triangles to make it appear like a continuous surface.

Leaky Geometry

The most common problem these days with STL files is leaky geometry. When your CAD tool creates the STL file your solid may not be a true solid in that you have holes in your topology. This can be caused by gaps, ill-defined curves and surface, or corners (vertices) not lining up. If you cut out the triangles and glued them together then filled the resulting object with water, the water would leak out.

You CAD package can make leaky STL files if it has loosened up the tolerances on the geometry modeling to the point where edges on its surface do not really line up. They trick themselves into accepting this through some hand waving inside their database, and it really is not a problem till you want to do something with the surfaces. Something like make an STL file.

One way to fix this problem is to clean up the original geometry. Run diagnostics on it and see where there are holes. You should do this anyway because in the end, a messy solid will cause problems when you make your drawings, calculate tool paths, or try and do simulation.

If that is not an option, you can use repair software. If you use an RP service provider, they should be able to repair most STL files. But if you constantly need them to do so, you should really look at changing your modeling practices or investing in some repair tools.

If you are doing your own prototyping, you have two good options. The first is free: Meshlab. It is an open source tool for working with faceted geometry and has repair and diagnostic capabilities. It does a lot so the interface can be a bit confusing, but it is free. If you want to save time and probably money in the long run, we recommend that you purchase a copy of SolidView. It is purpose built for repairing STL files and can really cut down on your repair time.

Faceted Geometry

Even if your prototyping tool can read your geometry and make a valid part, it may come out looking all clunky because your geometry is to faceted. As discussed above, the STL file is made up of triangles. If you have too few triangles on a curved surface then it comes out looking all flat and ugly. Here is a simple example:

The key to controlling this is to set the options in your CAD package to create more facets.

This is such an important topic, we actually have a whole posting dedicated to it:

STL File Tolerance: A Short Explanation of Faceting and Chord Height

In the old days we tried to minimize the number of triangles in an STL file because that file had to be uploaded, often via a modem.  But now we can email very large files, so you can make some pretty big STL files. Don’t go crazy, but don’t sacrifice surface quality either.

Degenerate Triangles and Inverted Faces

It is very rare for a CAD tool to create bad triangles, but it happens every once in a while. When trying to create a build from an STL file you might get a “Degenerate Triangle” or “Inverted Faces” error message.  There is not much you can do with this other than try one of the repair tools mentioned above or try and fix your underlying geometry.  If you get this type of error, there is something very wrong with your solid model.

Feature Sizes

Another problem that people often run across is that some of their small features do not show up on their prototype.  This can be because their STL file is not refined enough and that can be solved by tightening up the tolerance on their STL file creation.  If that does not work, the feature may just be too small for the technology.  Take a look at what the true machine resolution is. Make sure that is is smaller than your smallest features.

Make an Investment in Productivity

Having a bad STL file can really slow down the rapid part of Rapid Prototyping.  That is why PADT recommends that you take the time when you create your solid models to make good, robust, water tight solids that can be used down stream.  If you have nasty geometry or a less than precise CAD tool (can anyone say CATIA) you may have to invest in a repair program like Meshlab or SolidView.  Some up-front investment will pay in the long run, especially when you need that prototype first thing in the morning.

3D Printing, Rapid Prototyping, Additive Manufacturing? What is the Difference?

imageThe technology called 3D Printing is getting a lot of press lately. Articles like “3D Printing is the New Personal Computer” and “The New MakerBot Replicator Might Just Change Your World” are all over this place in the fall of 2012.  For those of us who have been printing 3D parts since the early 1990’s, this new frenzy can be a imagebit annoying. At every trade show that PADT goes to these days a large number of non-technical people come up and start telling us about 3D Printing and how it is going to “change everything.”  The next question is almost always “Is that a big 3D Printer?” as they point at a nice big FORTUS 400.  “Well, no, that is a digital manufacturing center, which is a rapid prototyping technology that uses similar technology to 3D Printing but it is much more precise, the material…” and by that point their eyes glaze over and they start playing with the model of the USS Enterprise we put out on the table to attract people.

By sorting through branding, media hype, and the confusing array of new low cost technologies, some clarity can be found and direction for those of us who use these technologies for product development. 

Additive Manufacturing

The first place to start is to recognize that we are talking about additive manufacturing technologies.  Taking a part definition and adding material through a variety of methods to make a physical part.  In almost every case, you build a part by adding thin layers of material one on top of another. The additive process differentiates this type of manufacturing from molding, forming, and machining – all of which remove or shape material.

The advantage of additive manufacturing is that you have very few constraints on the shape of your final part and there is no tooling, no programming, and very little manual interaction with the process.  This has huge advantages over the traditional manufacturing methods when it comes to speed.  Although you pay a price in strength, material selection, and surface finish, you can get parts quickly without a lot of effort.

Rapid Prototyping

Additive manufacturing took off in the late 80’s because it allowed engineers to make prototypes of their parts quickly and easily.  Rapidly.  And that is why for almost twenty years, most people who use additive manufacturing refer to it as rapid prototyping.  And to this day, most of the users of additive manufacturing use it for making prototypes as part of their product development process.  RP sounds better than AM, and better describes what you use the technology for rather than the technology. So that name took off and has stuck.

Other Names, Other Uses

As the technology got better, and especially as the materials got better, people started using additive manufacturing for other uses beyond making prototypes.  And, as is the way of companies that are trying to sell stuff, the manufacturers starting coining new names for the applications as users come up with them:

  • Rapid Patterns: making a part that will be used as a pattern in a downstream manufacturing process.  This is very common with jewelry in that the pattern is used in a lost-wax process for casting.  It is also used a lot with soft tooling, where the pattern is used to make a negative mold out of a soft rubber material.
  • Rapid Tooling: Making fixtures and molds using additive manufacturing. Tools can be used as patterns for forming, patterns for casting, or even for making molds for injection molding.
  • Direct Digital Manufacturing:  This is one of my favorite names and abbreviations – DDM.  The difference here is that the additive manufacturing process is used to make a final product, not just a prototype. 
  • Rapid Manufacturing: The same as Direct Digital Manufacturing, but without the alliteration.

3D Printing

According to Wikipedia the term 3D Printing was invented at MIT in 1995 when someone used an inkjet printing head to “print” a binder on to a bed of powder.  They used a printer to do their additive manufacturing, and used the term 3D Printing to describe it. By the way, they went on to form ZCorp, the second most popular additive manufacturing process in the world. 

Even though it started being used to refer to an inkjet printing based approach, the name spread over time. The term really caught on because it is so descriptive. Additive Manufacturing, and even Rapid Prototyping, do not make a lot of sense to non-engineers. 3D Printing makes sense immediately to pretty much anyone.

Those of us who are diehards really want 3D Printing to refer to lower cost, affordable devices that make lower end prototypes.  And if you look at how the name is applied by the manufacturers, that is generally how it was used.  Here is a screen shot of the Stratasys home page, and see how they split their systems into 3D Printers and 3D Production systems:


But the name is working so well that we are seeing a shift towards refereeing to additive manufacturing as printing.  3DSystems is going full bore and as of this writing, refers to their whole line as “Printers” and differentiates them by calling them “personal, professional, and production.”


What is Old is New Again

So it looks like the trend is towards 3D Printing becoming the new term for an old technology. And those of us who call them RP machines will have to stop doing that, or just accept that we will be met with blank stares when we do.  So next time someone comes up to tell me they just read an article in Good Housekeeping about how they will be able to make replacement parts for their dish washer in the garage with a 3D Printer, I will smile and say “That is great. In fact, we use almost all of the major 3D Printing technologies in house at PADT, and we resell the most popular 3D Printers from Stratasys, Inc.  That includes that big FORTUS 900.  It is a big and accurate 3D Printer”