Jeff's MCAD Blogging
Jeffrey Rowe has more than 40 years of experience in all aspects of industrial design, mechanical engineering, and manufacturing. On the publishing side, he has written well over 1,000 articles for CAD, CAM, CAE, and other technical publications, as well as consulting in many capacities in the … More »
August 17th, 2017 by Jeff Rowe
Like it or not, since the mid-1980s, the STL file format has been the de facto industry standard for transferring information between CAD programs and additive manufacturing equipment. However, the STL format only contains information about a surface mesh, and cannot represent color, texture, material, substructure, and other properties of a fabricated object.
As additive manufacturing technology has evolved from producing primarily single-material, homogenous shapes to producing multi-material geometries in full color with functionally graded materials and microstructures, there has been a growing need for a standard interchange file format that could support these features. A second factor that prompted the development of a new standard was the improving resolution of additive manufacturing machines. As the fidelity of printing processes approached micron scale resolution, the number of triangles required to describe smooth curved surfaces resulted in unacceptably large file sizes.
The Additive Manufacturing File Format (AMF) was introduced as an alternative to the STL file format to address many of the shortcomings of the popular file format. STL files introduce errors such as leaks and inconsistences, and also does not support color, material The choice, or orientation. STL files also rely on triangle subdivision to account for curvature. As the STL file scales in size, retaining resolution means introducing significantly more triangles. For example, a 10cm sphere at 10 micrometer resolution requires 20,000 triangles. Scaling up the 10cm sphere at the same resolution would significantly increase the amount of triangles, resulting in a much larger file. AMF seeks to address these issues by redesigning the way a 3D object is digitally stored.
August 10th, 2017 by Jeff Rowe
Since the dawn of 3D printing, a little over three decades ago, there has been one file format that has dominated communicating with 3D printers — STL. Love it or hate it, and even with its limitations and shortcomings, STL has remained the de facto standard for the 3D printing industry. That may finally be changing, though, with the advent of more contemporary and robust file formats for 3D printing, such as AMF and 3MF. Over the next couple weeks we’ll be discussing the evolution, advantages, and disadvantages of 3D printing file formats, starting this week with STL.
So What Exactly Is An STL File?
Essentially, an STL file stores information about 3D models, but this format describes only the surface geometry of a 3D object without any representation of color, texture, or other common model attributes.
As it has been for three plus decades, the STL file format is still by far the most commonly used file format for communicating with 3D printers.
The true meaning of the file extension .STL has always been somewhat of a mystery. I’ve always considered it be an abbreviation of the word STereoLithography, although sometimes I have also heard it referred to as Standard Triangle Language or Standard Tessellation Language. Which is correct? Probably all of them.
Introduction To The STL File Format
The main purpose of the STL file format is to encode the surface geometry of a 3D object using tessellation. Tessellation is the process of tiling a surface with one or more geometric shapes with no overlaps or gaps. Having no gaps is especially important, as an object must be watertight to be printed. A good real life example of tessellation is a tiled floor.
August 3rd, 2017 by Jeff Rowe
This week at SIGGRAPH, HP today announced a unified approach and commercial solutions for virtual reality (VR), positioning itself as a provider for businesses looking to reduce concept to production cycle times, improve training procedures, and deliver fully immersive customer experiences using VR. As part of this strategy, the company unveiled what it claims is the world’s first professional-grade wearable VR PC – the new HP Z VR Backpack. Designed to realize a fuller potential of VR, it is, as the company claims, a secure and manageable wearable VR PC.
“Virtual reality is changing the way people learn, communicate and create,” said Xavier Garcia, vice president and general manager, Z Workstations, HP Inc. “Making the most of this technology requires a collaborative relationship between customers and partners. As a leader in technology, HP is uniting powerful commercial VR solutions, including new products like the HP Z VR Backpack, with customer needs to empower VR experiences our customers can use today to reinvent the future.”
HP Z VR Backpack Docked
Well beyond gaming, the opportunities for commercial VR are virtually (sorry for the pun) limitless for businesses in product design, architecture, healthcare, first responder training, automotive, and entertainment. Technologies like VR can provide unique experiences, ranging from reinventing the buying experience in automotive showrooms to changing the way fire departments train their staff.
HP Z VR Backpack
July 27th, 2017 by Jeff Rowe
The Society of Manufacturing Engineers (SME), a nonprofit organization that supports the manufacturing industry, and Stratasys Ltd. announced the winners of a student additive manufacturing competition held during the 53rd annual SkillsUSA National Leadership and Skills Conference.
The SkillsUSA Additive Manufacturing Competition is a student contest co-sponsored by the organizations to attract the future workforce to this growing field and allow contestants to get hands-on experience using the latest 3D printing software and technology, such as the new Stratasys F123 Series. The competition was held at the 53rd annual SkillsUSA National Leadership and Skills Conference, and six teams took home gold, silver and bronze medals for fulfilling all of the contest requirements.
Now in its third year, the 2017 Additive Manufacturing Competition consisted of 34 high school and post-secondary student teams competing for a chance to take home gold, silver, or bronze medals – as well as scholarships from the SME Education Foundation, and a MakerBot Mini printer. The Additive Manufacturing Competition was created to stimulate student learning of additive manufacturing and 3D printing techniques.
“Each year, we attract more students to participate in the SkillsUSA Additive Manufacturing Competition and we couldn’t be more thrilled with the growth,” said Jeff Krause, executive director and CEO of SME. “This is an exciting time for additive manufacturing and 3D printing and we are proud to be at the forefront of its evolution and making sure our future manufacturing leaders will be prepared for what lies ahead as the industry progresses.”
The 2017 Additive Manufacturing Competition involved designing and printing a track piece (fixture) capable of moving a marble to a designated location after the ball rolls down a ramp. The fixture was required to connect with the ramp at specific points and remain stable for the test’s duration. Each team was provided time to design the fixture, build the 3D printed prototype on a Stratasys 3D printer, and make any necessary design modifications the next day. Read the rest of SME and Stratasys Announce Winners of the 2017 SkillsUSA Additive Manufacturing Competition
July 13th, 2017 by Jeff Rowe
ANSYS, known for its engineering simulation software, announced this week that it has acquired Computational Engineering International Inc. (CEI), the developer of a suite of products for analyzing, visualizing, and communicating simulation data. Terms of the deal, which closed earlier this month, were not disclosed.
The merger of the physical and digital worlds is resulting in products that with an overwhelming number of design decisions compared to previous product generations. That is something only engineering simulation can feasibly provide in a timely and cost-effective fashion. Users need to quickly analyze the huge amount of data that simulation generates to make the best engineering and business decisions.
Headquartered in Apex, North Carolina, CEI has 28 employees and more than 750 customers around the world. Its flagship product, EnSight, is used for analyzing, visualizing, and communicating simulation data in terms that mere mortals can comprehend.
“CEI has a long track record of success thanks to fantastic technology built by a world-class team,” said Mark Hindsbo, ANSYS vice president and general manager. “By bringing CEI’s leading visualization tools into the ANSYS portfolio, customers will be able to make better engineering and business decisions, leading to even more amazing products in the future.”
July 6th, 2017 by Jeff Rowe
An impossible object is a type of optical illusion. It consists of a two-dimensional figure that is instantly and subconsciously interpreted by the visual system as representing a projection of a three-dimensional object.
In most cases the impossibility becomes apparent after viewing the figure for a few seconds. However, the initial impression of a 3D object remains even after it has been contradicted. There are also more subtle examples of impossible objects where the impossibility does not become apparent spontaneously and it is necessary to consciously examine the geometry of the implied object to determine that it is impossible.
The unsettling nature of impossible objects occurs because of our natural tendency to interpret 2D drawings as 3D objects. With an impossible object, looking at different parts of the object makes one reassess the 3D nature of the object, which confuses the mind.
Although possible to represent in two dimensions, it is not geometrically possible for such an object to exist in the physical world. However, some models of impossible objects have been constructed, such that when they are viewed from a very specific point, the illusion is maintained. Rotating the object or changing the viewpoint breaks the illusion, and therefore many of these models rely on forced perspective or having parts of the model appearing to be further or closer than they actually are.
Below is the Penrose triangle (an impossible object) that was first created by the Swedish artist Oscar Reutersvärd in 1934. The mathematician Roger Penrose independently devised and popularized it in the 1950s, describing it as “impossibility in its purest form.”
A 3D-printed version of the Reutersvärd Triangle illusion, its appearance created by a forced perspective.
So what does all this have to do with MCADCafe?
June 29th, 2017 by Jeff Rowe
At SOLIDWORKS World 2017 we got introduced to Xometry, a company committed to bringing manufacturing back to the U.S. with its software platform for building a reliable and scalable manufacturing source program. It employs a unique machine-learning approach that provides customers with optimized manufacturing capabilities at the best price based on parameters input by customers.
Founded in 2014, Xometry is hoping to transform American manufacturing through its proprietary software platform that provides on-demand manufacturing to a diverse customer base that ranges from startups to Fortune 100 companies. The platform provides an efficient way to source high-quality custom parts, with 24/7 access to instant quote pricing, expected lead time, and manufacturability feedback that recommends best processes and practices. With more than 100 manufacturing partners, the manufacturing capabilities include CNC machining, 3D printing, sheet metal forming and fabrication, and urethane casting with over 200 materials. Xometry’s 5,000+ customers include General Electric, MIT Lincoln Laboratory, NASA, and the United States Army.
Below is a video interview we conducted at SOLIDWORKS World 2017 with Randy Altschuler, CEO and co-founder of Xometry.
Randy Altschuler, CEO, Xometry at SOLIDWORKS World 2017
June 22nd, 2017 by Jeff Rowe
Last month at the RAPID + TCT event, many new things were presented and among those was GE Additive’s setting a target of growing its new additive manufacturing business to $1 billion by 2020, and selling 10,000 metal 3D printing machines in 10 years, building upon acquisitions it announced last year.
“It’s a big number,” said Tim Warden, senior sales director of GE Additive. “That’s why they’re investing heavily,” he said, referring to GE.
GE controls Concept after agreeing last October to buy an initial 75% stake in the German company, with plans to acquire the rest over an undisclosed number of years. The GE Additive turned to Concept Laser after a previously announced deal with SLM Solutions fell through.
The company estimates that it ultimately can expand additive manufacturing into a $10 billion business. GE owns more than 70% of Arcam but doesn’t have full control of the Swedish company.
The following video shows GE Power’s advanced manufacturing facility in Greenville, SC to learn about GE Additive’s metal 3D printing process for creating a gas turbine component that is used to power homes.
GE Additive and the Power of Additive Manufacturing
For now, “We’re concentrating on Concept where we can do what we want to do,” Warden said. “We’re going to support Concept in every way possible.”
June 15th, 2017 by Jeff Rowe
Las Vegas in June . . . Good idea or bad idea? I’ll try and stay neutral on this one, but this town is not exactly my favorite, regardless of time of year. However, it’s always worth the trip when a company like Hexagon invites me for its annual international conference, HxGN LIVE 2017.