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Engineer's Toolbox: How to design the optimum hinge

Although many pin styles are available, Coiled Spring Pins are particularly well suited for use in both friction- and free-fit hinges. To achieve optimum long-term hinge performance, designers should observe these helpful design guidelines from SPIROL.
Read the full article.

Innovative new robo welding gun

Comau's newest N-WG welding gun is designed for high-speed spot welding for traditional, hybrid, and electric vehicles, in addition to general industry sectors. It features a patented, single-body architecture that enables rapid reconfiguration between welding types and forces, and it delivers consistent performance across a broad range of applications, including steel and (soon) aluminum welding. It supports both X and C standard gun configurations, has fast arm exchange, and universal mounting options. It is fully compatible with major robot brands and represents a significant advancement in spot welding performance and cost efficiency.
Learn more.

What's a SLIC Pin^®? Pin and cotter all in one!

The SLIC Pin (Self-Locking Implanted Cotter Pin) from Pivot Point is a pin and cotter all in one. This one-piece locking clevis pin is cost saving, fast, and secure. It functions as a quick locking pin wherever you need a fast-lock function. It features a spring-loaded plunger that functions as an easy insertion ramp. This revolutionary fastening pin is very popular and used successfully in a wide range of applications.
Learn more.

Engineering challenge: Which 3D-printed parts will fade?

How does prolonged exposure to intense UV light impact 3D-printed plastics? Will they fade? This is what Xometry's Director of Application Engineering, Greg Paulsen, set to find out. In this video, Paulsen performs comprehensive tests on samples manufactured using various additive processes, including FDM, SLS, SLA, PolyJet, DLS, and LSPc, to determine their UV resistance. Very informative. Some results may surprise you.
View the video.

Copper filament for 3D printing

Virtual Foundry, the company that brought us 3D-printable lunar regolith simulant, says its popular Copper Filamet™ (not a typo) is "back in stock and ready for your next project." This material is compatible with any open-architecture FDM/FFF 3D printer. After sintering, final parts are 100% pure copper. Also available as pellets. The company says this is one of the easiest materials to print and sinter. New Porcelain Filamet™ available too.
Learn more and get all the specs.

Copper foam -- so many advantages

Copper foam from Goodfellow combines the outstanding thermal conductivity of copper with the structural benefits of a metal foam. These features are of particular interest to design engineers working in the fields of medical products and devices, defense systems and manned flight, power generation, and the manufacture of semiconductor devices. This product has a true skeletal structure with no voids, inclusions, or entrapments. A perennial favorite of Designfax readers.
Learn more.

Full-color 3D-printing Design Guide from Xometry

With Xometry's PolyJet 3D-printing service, you can order full-color 3D prints easily. Their no-cost design guide will help you learn about different aspects of 3D printing colorful parts, how to create and add color to your models, and best practices to keep in mind when printing in full color. Learn how to take full advantage of the 600,000 unique colors available in this flexible additive process.
Get the Xometry guide.

Tech Tip: How to create high-quality STL files for 3D prints

Have you ever 3D printed a part that had flat spots or faceted surfaces where smooth curves were supposed to be? You are not alone, and it's not your 3D printer's fault. According to Markforged, the culprit is likely a lack of resolution in the STL file used to create the part.
Read this detailed and informative Markforged blog.

Test your knowledge: High-temp adhesives

Put your knowledge to the test by trying to answer these key questions on how to choose the right high-temperature-resistant adhesive. The technical experts from Master Bond cover critical information necessary for the selection process, including questions on glass transition temperature and service temperature range. Some of the answers may surprise even the savviest of engineers.
Take the quiz.

Engineer's Toolbox: How to pin a shaft and hub assembly properly

One of the primary benefits of using a coiled spring pin to affix a hub or gear to a shaft is the coiled pin's ability to prevent hole damage. Another is the coiled pin absorbs wider hole tolerances than any other press-fit pin. This translates to lower total manufacturing costs of the assembly. However, there are a few design guidelines that must be adhered to in order to achieve the maximum strength of the pinned system and prevent damage to the assembly.
Read this very informative SPIROL article.

What's new in Creo Parametric 11.0?

Creo Parametric 11.0 is packed with productivity-enhancing updates, and sometimes the smallest changes make the biggest impact in your daily workflows. Mark Potrzebowski, Technical Training Engineer, Rand 3D, runs through the newest functionality -- from improved surface modeling tools to smarter file management and model tree navigation. Videos provide extra instruction.
Read the full article.

What's so special about wave springs?

Don't settle for ordinary springs. Opt for Rotor Clip wave springs. A wave spring is a type of flat wire compression spring characterized by its unique waveform-like structure. Unlike traditional coil springs, wave springs offer an innovative solution to complex engineering challenges, producing forces from bending, not torsion. Their standout feature lies in their ability to compress and expand efficiently while occupying up to 50% less axial space than traditional compression springs. Experience the difference Rotor Clip wave springs can make in your applications today!
View the video.

New Standard Parts Handbook from JW Winco

JW Winco's printed Standard Parts Handbook is a comprehensive 2,184-page reference that supports designers and engineers with the largest selection of standard parts categorized into three main groups: operating, clamping, and machine parts. More than 75,000 standard parts can be found in this valuable resource, including toggle clamps, shaft collars, concealed multiple-joint hinges, and hygienically designed components.
Get your Standard Parts Handbook today.

Looking to save space in your designs?

Watch Smalley's quick explainer video to see how engineer Frank improved his product designs by switching from traditional coil springs to compact, efficient wave springs. Tasked with making his products smaller while keeping costs down, Frank found wave springs were the perfect solution.
View the video.

Top die casting design tips

You can improve the design and cost of your die cast parts with these top tips from Xometry's Joel Schadegg. Topics include: Fillets and Radii, Wall Thicknesses, Ribs and Metal Savers, Holes and Windows, Parting Lines, and more. Follow these recommendations so you have the highest chance of success with your project.
Read the full Xometry article.

Particles emitted by consumer 3D printers could hurt indoor air quality

Consumer-grade 3D printers have grown in popularity in recent years, but the particles emitted from such devices can negatively impact indoor air quality and have the potential to harm respiratory health, according to a study from researchers at the Georgia Institute of Technology and UL Chemical Safety.

For the study, which was published September 12 in the journal Environmental Science & Technology and sponsored by Underwriters Laboratories, Inc. (UL)., the researchers collected particles emitted from 3D printers and conducted several tests to gauge their impact on respiratory cell cultures.

Rodney Weber, a professor in Georgia Tech's School of Earth & Atmospheric Sciences, stands in his lab alongside several consumer-grade 3D printers. [Credit: Allison Carter]

 

 

 

 

"All of these tests, which were done at high doses, showed that there is a toxic response to the particles from various types of filaments used by these 3D printers," said Rodney Weber, a professor in Georgia Tech's School of Earth & Atmospheric Sciences, who led the research.

The study was part of a multi-year research project aimed at characterizing particle emissions by the printers in a controlled environment and identifying measures that could be taken by both 3D-printer manufacturers and users to reduce the potential for harm. While earlier studies had focused on quantifying the particles being emitted, this time the researchers looked more closely at the chemical composition of the particles and their potential for toxicity.

3D printers typically work by melting plastic filaments and then depositing the melt layer upon layer to form an object. Heating the plastic to melt it releases volatile compounds, some of which form ultrafine particles that are emitted into the air near the printer and the object.

In earlier research, the team found that generally the hotter the temperature required to melt the filament, the more emissions were produced. As a result, acrylonitrile butadiene styrene (ABS) plastic filaments, which require a higher temperature to melt, produced more emissions than filaments made of polylactic acid (PLA), which melt at a lower temperature.

To test the impact of the emissions on live cells, the researchers partnered with Weizmann Institute of Science in Israel, which exposed human respiratory cells and rat immune system cells to concentrations of the particles from the printers. They found that both ABS and PLA particles negatively impacted cell viability, with the latter prompting a more toxic response. But these tests did not reflect actual exposures

The researchers also performed a chemical analysis of particles to gain further insight into their toxicity and allow comparisons to toxicity of particles found in outdoor urban environments. The analysis -- called oxidative potential -- simulates the toxic response that an aerosol would have on cellular organisms.

"The toxicity tests showed that PLA particles were more toxic than the ABS particles on a per-particle comparison. But because the printers emitted so much more of the ABS, it's the ABS emissions that end up being more of the concern," Weber said. "Taken together, these tests indicate that exposure to these filament particles could, over time, be as toxic as the air in an urban environment polluted with vehicular or other emissions."

Another finding of the study was that the ABS particles emitted from the 3D printers had chemical characteristics that were different than the ABS filament.

"When the filament companies manufacture a certain type of filament, they may add small mass percentages of other compounds to achieve certain characteristics, but they mostly do not disclose what those additives are," Weber said. "Because these additives seem to affect the amount of emissions for ABS, and there can be great variability in the type and amount of additives added to ABS, a consumer may buy a certain ABS filament, and it could produce far more emissions than one from a different vendor."

The study also looked at which types of indoor environmental scenarios emissions from a 3D printer would most impact. They estimated that in a commercial building setting such as a school or an office, better ventilation would limit the amount of exposure to the emissions. However, in a typical residential setting with less effective ventilation, the exposure could be much higher, they reported.

"These studies show that particle and chemical emissions from 3D printers can result in unintentional pollutant exposure hazards, and we are pleased to share this research so that steps can be taken to reduce health risks," said Marilyn Black, senior technical advisor for UL.

In the meantime, some measures can be taken by operators of 3D printers to lessen their impact on air quality:

• Operating 3D printers only in well-ventilated areas;
• Setting the nozzle temperature at the lower end of the suggested temperature range for filament materials;
• Standing away from operating machines; and
• Using machines and filaments that have been tested and verified to have low emissions.

CITATION: Qian Zhang, Michal Pardo, Yinon Rudich, Ifat Kaplan-Ashiri, Jenny P.S. Wong, Aika Y. Davis, Marilyn S. Black and Rodney J. Weber, "Chemical Composition and Toxicity of Particles Emitted from a Consumer-Level 3D Printer Using Various Materials," (Environmental Science & Technology, September 2019).

Source: Georgia Tech

Published October 2019

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