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Weird stuff: Moon dust simulant for 3D printing

Crafted from a lunar regolith simulant, Basalt Moon Dust Filamet™ (not a typo) available from The Virtual Foundry closely mirrors the makeup of lunar regolith found in mare regions of the Moon. It enables users with standard fused filament fabrication (FFF) 3D printers to print with unparalleled realism. Try out your ideas before you go for that big space contract, or help your kid get an A on that special science project.
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Make nylon 3D-printed prototypes and parts in the office

The new SLS 300 from 3D Systems is an affordable, turnkey, closed-loop 3D-printing system designed to operate in a smaller-footprint environment. SLS 300 makes selective laser sintering available to a broader range of customers with a high-reliability, affordable solution to produce end-use parts. Users can produce tough, durable parts from a range of production-grade nylon materials. Amazing fill, finishing, and clean-up systems.
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Will it erode? 3D-printing materials comparison from Xometry

Which 3D-printed plastics are the toughest? In this "Will it ..." video, Greg Paulsen, Xometry's Director of Application Engineering, 3D printed Benchies (3D test models) using different materials (such as polycarbonate, PLA, polypropylene, ULTEM, and Nylon 11 and 12) and processes (such as FDM, SLS, MJF, SLA, LSPc, Polyjet, and DLS) and then ran several abrasion tests on them. Watch to find out which 3D-printed plastic is truly the toughest of them all!
View Part 1.
View Part 2.

Graphene Handbook: Learn all about this wonder material

Metalgrass LTD has published the 11th edition of its "Graphene Handbook," a comprehensive resource on graphene technology, the industry, and the market for this wonder material made of single layers of atoms of pure carbon. The book includes development history, production methods, current research, an intro to metrology and standardization, and even an investment guide. Under 100 bucks for digital edition. Hard copy available too.
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Who knew? How colorants affect plastic

In plastic injection molding, one aspect of polymer characteristics that doesn't always get the consideration it deserves is the addition of colorant. Believe it or not, there is a whole scientific body of knowledge about the ways in which adding color to plastic can affect its behavioral properties. This short article by Denny Scher of ICO Mold takes a high-level look at some of the different, and surprising, ways colorants can affect plastics.
Read the full article.

Retaining magnets from JW Winco: Universal and clever

JW Winco has expanded its magnet line to support more applications with new materials, shapes, systems, and even raw magnets. Learn about their latest offerings, including retaining magnets designed for corrosive environments (GN 50.8), encapsulated magnets designed for sensitive or painted surfaces (GN 51.8), handle magnets (GN 53.3), and powerful magnets designed to handle challenging environs (GN 52.6).
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3D print tool steel with the ease of a plastic

The Virtual Foundry, a pioneer in advanced 3D-printing materials, is excited to announce the launch of their latest innovation: M300 Tool Steel Filamet™ (not a typo). This material answers the demand for FFF 3D-printable Tool Steel, delivering unparalleled strength and versatility. What sets this material apart is its seamless compatibility with various 3D printers, including Creality, Bambu Lab, Ultimaker, and more. The filament prints effortlessly, resembling the ease of working with PLA (plastic).
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Great Resources: Sheet metal design guide

If you're looking for a basic guide to sheet metal design, this one from Xometry will serve your needs well. Follow the design requirements and tolerances in this guide to ensure parts fall closer to design intent. This is the type of information you'll sock away and then refer to again and again.
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Particle foam perfectly distributed thanks to simulation with Ultrasim

BASF's Ultrasim simulation solution now includes Infinergy, an expanded thermoplastic polyurethane (E-TPU) that is used in a wide range of applications to make components with particle foam -- from bicycle tires to the soles on shoes. Identify and solve problems related to pneumatic filling when distributing particle foams in molds, even taking gravity and mold closing into consideration. Avoid those pesky air pockets.
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Premium polymer DLP printer is half the price of its predecessor

Desktop Metal has just launched the ETEC Pro XL -- a premium polymer digital light processing (DLP) printer that enters the market at less than half the price as its predecessor. DLP is regarded by many as a superior polymer 3D-printing technology for speed, surface finish, and accuracy. Ideal for automotive and machine parts, aerospace components, housings, connectors, jigs and fixtures, short-run molds, and more.
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CNC machining case study: One-of-a-kind computer chassis

Learn how Josh Sniffen, the YouTuber behind the popular PC-building channel "Not From Concentrate," trusted Xometry to provide a wide range of manufacturing options, personalized Design for Manufacturing (DFM) feedback, and order management support for his latest creation: the HEXO ATX computer chassis. All in all, Sniffen procured parts using Xometry's CNC machining service, selective laser sintering 3D-printing service, and sheet metal cutting and fabrication services. A neat insider look at the process.
Read this Xometry case study.

Which parts should be 3D printed? AI combs through CAD files to find out

One of the biggest challenges in transitioning to additive manufacturing (AM) is the ability to identify which parts are best suited for the process quickly and easily. Learn how Danfoss, Stanley Engineered Fastening, and even the U.S. military have utilized advanced additive manufacturing software to automate the process, reducing material waste and energy costs, improving part reliability, decreasing lead times, as well as now having the ability to identify part consolidation opportunities through intelligent AM decision-making.
Read the full article.

9 key design tips for injection molding

Keep costs down and quality up all while optimizing your injection molded designs with these helpful tips from Xometry. Learn how to build better injection molded parts and products -- using draft angles, ribs and gussets, radii, fillets, and more -- and set expectations for the injection molding process. Good info here.
View the video.

Metal additive manufacturing: Rocket turbopump design

Mixing undergraduate curiosity and real-world engagement, two students from Colorado University Boulder Aerospace Engineering Sciences program, Zachary Lesan and Patrick Watson, started an independent effort on turbopump design and manufacture that is a lesson in determination and industry collaboration. With lots of supplies and advice from industry heavy hitters including Velo3D, CFturbo, SpaceX, and many more, their project has reinforced significant points being made about next-generation rocketry.
Read the full article.

Transparent ceramics for extreme optics

Sapphire is an inherently transparent ceramic material that is resistant to extremes of temperature and environment. Sapphire can be processed to unique and precise shape/form by diamond grinding and polishing to allow full transparency. INSACO is a global leader in this capability -- and working with ultra-hard materials in general.
Learn more.

Using a 'fluid mechanical sewing machine,' researchers develop model that predicts patterns that form from honey-like fluids

By Jennifer Chu, MIT

Drizzling honey on toast can produce mesmerizing, meandering patterns, as the syrupy fluid ripples and coils in a sticky, golden thread. Dribbling paint on canvas can produce similarly serpentine loops and waves.

The patterns created by such viscous fluids can be reproduced experimentally in a setup known as a "fluid mechanical sewing machine," in which an overhead nozzle deposits a thick fluid onto a moving conveyor belt. Researchers have carried out such experiments in an effort to identify the physical factors that influence the patterns that form.

Researchers use numerical simulations to predict different patterns that may form when viscous threads fall onto a moving belt. [Image: P.T. Brun]

 

 

Now a group of mathematicians at MIT, Cambridge University, and elsewhere have developed a simple model to predict patterns formed by viscous fluids as they fall onto a moving surface.

The researchers looked at four patterns -- sinusoidal waves; repeating and alternating loops; and straight lines -- and observed that the pattern formed depends on the ratio between the fluid's speed on impact and the speed of the conveyor belt. The team found that this ratio influences a fluid's shape, or curvature, just before hitting the surface, which in turn determines the pattern that forms.

The team used its model to create simulations of viscous flow; these simulations matched the patterns produced in previous experiments by others.

The simple geometrical model may be easily integrated into computer graphics simulations to create realistic videos of viscous liquids like honey and oil. The model may also be used to optimize manufacturing processes for products such as nonwoven materials -- synthetic fabrics that are manufactured through an injection process that sprays polymers onto a conveyor belt, in patterns meant to resemble woven textiles.

Pierre-Thomas Brun, an instructor in MIT's Department of Mathematics, says the geometrical model provides a simple method to both predict and create patterns from viscous fluids.

"We're getting at the core of pattern formation, and explaining why transitions from pattern to pattern occur, with a very minimalistic model," Brun says. "With this method, you can have a 3D printer inject your polymer and just move the belt at the appropriate speed, and you can get the patterns you want."

Brun and his colleagues published their results recently in the journal Physical Review Letters.

"Boiling down" viscous flow
In 2012, researchers at the University of Toronto carried out a fluid mechanical sewing machine experiment, drizzling a viscous fluid onto a progressively slowing conveyor belt. The experiment showed that as the belt starts moving rapidly, the fluid forms a straight line as it hits the surface. As the belt slows, the fluid, flowing at the same rate, starts to meander in a wavelike pattern, then form alternating loops, and then finally, repeating loops, as the conveyor belt grinds almost to a halt.

Brun and others have studied these experimental results, and have since come up with a detailed numerical model, called "discrete viscous robes numerics," to describe the resulting patterns, depending on factors such as fluid height, viscosity, and gravity. But Brun says this model, though precise in its predictions, contains many equations that are complex to solve.

Instead, he and his group sought to "boil down" the dynamics of viscous flow into a simpler, workable model, mainly by doing away with a complex variable: inertia, an object's resistance to any change in motion. For instance, in the case of the fluid mechanical sewing machine, the rotation of the thread generates centrifugal forces in the coil that forms on the conveyor belt.

Brun chose to model the system without inertia, in a scenario in which fluid flows from a very small height -- a scenario in which the fluid stretches under the force of gravity, but inertia does not play a role. Under these conditions, he observed that the patterns formed were the same as those created with the full, inertia-driven numerical model -- a sign that something other than inertia was determining pattern formation.

Digging into the "heel" of the problem
Brun and his colleagues found that the crux of the issue came down to what they termed the "heel" of the flow -- the point just before impact, when a fluid curves slightly, forming a heel-like shape. The researchers found that the patterns formed on the conveyor belt depend on the shape of the fluid heel. They noted the shape, or curvature, of the heel was determined by the distance and orientation between two points: the point at which the fluid first contacts the surface, and the point directly below the nozzle.

These two properties shape the curvature of the fluid as it hits the belt. The group also found that the resulting curvature determines the new angle and impact point of the fluid -- a phenomenon that induces a "memory" effect in the fluid.

"Memory is usually induced by inertia, but despite the fact that here there is no inertia, we still maintain this idea of memory, which is essential for formation of patterns," Brun says. "It's really embedded in these geometry features. Otherwise, the patterns would just be random."

Brun and his colleagues used their model to simulate the fluid mechanical sewing machine scenario, changing the shape of the heel in response to the speed of the conveyor belt. They produced four main patterns -- waves, straight lines, and alternating and repeating loops -- that matched the patterns generated by the more detailed numerical model.

Video: In earlier research, MIT scientists produced patterns of coils in the lab that simulations were able to predict. [Video: Melanie Gonick/MIT]

The researchers say their simplified model may be geared toward optimizing a novel class of microfabrication techniques for manufacturing extremely small, tailorable textured fibers.

"We now have a very powerful tool we can use to get to the core of the experiment, to get deeper into the way these patterns are formed," Brun says.

Dominic Vella, an associate professor of applied mathematics at Oxford University, says, "What is really important and elegant about this paper is that they have reduced the problem to a much simpler formulation. This means that they are able to gain new understanding of the process, especially the crucial role of geometry."

Vella, who was not involved with the research, sees multiple applications for the model.

"It could be a useful practical tool for understanding how fast telecommunications cables can be laid down, and at the other end of the spectrum, what parameter regimes should be used to obtain a particular pattern in nonwoven textiles," he says. "At the frivolous end, perhaps one could make an iPhone app that would tell you how fast to ice a cake to get a given pattern."

This research was funded in part by the European Research Council.

Published May 2015

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