Designfax weekly eMagazine

Subscribe Today!

Archives

View Archives

Partners

Manufacturing Center
Product Spotlight

Modern Applications News
Metalworking Ideas For
Today's Job Shops

Tooling and Production
Strategies for large
metalworking plants

How ball spline coatings enhance performance and extend component life

According to Thomson, "Precision ball splines have gained popularity as an ideal choice for applications that require low-friction linear and rotary motion. These components, which utilize a single splined shaft, enable complex movements in multiple directions." But how do you keep these ball splines performing at their peak for longer? Coatings can do the trick, and Thomson has three of them: black oxide, hard chrome plating, and nickel plating. Learn more about these coatings and which one makes the most sense for your precision ball spline solution.
View the video.

Key factors for ball screw applications

Learn the six key factors that should be considered when specifying ball screw assemblies in motion control applications. PCB Linear gathered a panel of experts in the field of linear motion to concentrate on this important topic -- particularly when it comes to the company's new miniature ball screw product line. Learn about precision and accuracy, orientation, speed and acceleration, duty cycle, linear motion travel, and load capacity. Podcast available too.
Read the PCB Linear blog.

3D printer uses pellet extrusion system instead of filament

The latest addition to 3D Systems' industry-leading portfolio of EXT Titan Pellet systems is the EXT 800 Titan Pellet. With a build volume of 800 x 600 x 800 mm, this thermoplastics 3D printer harnesses the speed, reliability, and efficiency of the company's large-format pellet systems in a more compact unit with lower upfront investment. Use this machine to fabricate more modestly sized functional prototypes, tooling, fixtures, sand casting patterns, thermoforming molds, and end-use parts. Markedly faster than competing FFF and FDM printers, and up to 10X reduced material costs compared to filaments.
Learn more.

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.

World's first current-carrying fastening technology

PEM^® eConnect™ current-carrying pins from Penn-Engineering provide superior electrical connections in applications that demand high performance from internal components, such as automotive electronics. This first-to-market tech provides repeatable, consistent electrical joints and superior installation unmatched by traditional fastening methods. Features include quick and secure automated installation, no hot spots or poor conductivity, and captivation options that include self-clinching and broaching styles.
Learn more about eConnect pins.

New flat quarter-turn clamping fastener

IMAO Fixtureworks has expanded its One-Touch Fastener lineup to include a new quarter-turn clamping fastener that features an innovative flat design and is ideal for clamping in limited spaces. The QCFC flat quarter-turn fastener features a recessed body that protrudes only 2 mm from the mounted surface, a knob that rests flush inside the body, visible ON and OFF markings for safety, and an audible click when fully turned to clamped or unclamped position.
Learn more.

Bellows and disc couplings with higher torque capacity

Ruland Manufacturing now offers bellows and double disc couplings with bore sizes up to 1-3/4 in. or 45 mm for use in systems with torque up to 1,400 in.-lb (158 Nm). High-torque applications in precision semiconductor, solar, conveyor, and factory automation applications often use these shaft sizes. Ruland disc and bellows couplings accommodate all forms of misalignment, are zero-backlash, and have a balanced design for reduced vibration at speeds up to 10,000 rpm.
Learn more.

Simplify your designs with slewing ring bearings

According to Kaydon Bearings, "A slewing ring bearing has rolling elements designed to create a reactive moment within the bearing's dimensions envelope to oppose applied (overturning) moment load," so you can use one bearing instead of two, reducing the height requirements, and even improve performance. Slewing ring bearings can also simplify a drive system by utilizing gear teeth on the inner or outer race. Learn all about slewing ring bearings in this informative article.
Read the Kaydon whitepaper.

Jet valve for ultra-small dispensing

DELO's DELO-DOT PN5 LV pneumatic jet valve is designed for micro-dispensing low-viscosity adhesives and other media in miniaturized applications. Thanks to its compact design, it also requires very little space to install in production systems. Interchangeable nozzles with different diameters and a flexible, adjustable plunger stroke ensure precise and reliable applications at different droplet sizes. Volumes of as low as 1 nl can be achieved, which corresponds to droplet diameters of 250 µm or less.
Learn more.

Stainless steel constant-torque flush-mount hinge

Southco has introduced a flush-mount version of its popular and durable E6 constant-torque hinge. Its low-profile, corrosion-resistant package makes it an ideal solution for maximizing security, longevity, and aesthetics. It offers high torque for demanding applications while maintaining its low profile. Lots of uses.
Learn more.

Claw vacuum pump for industrial applications

Vacuum expert Leybold has added a new model to its proven CLAWVAC dry claw vacuum pump series: the CLAWVAC CP B. This innovative, rough vacuum pump, designed for robust processes including food processing, material handling, and environmental industries, is powerful, energy efficient, and easy to clean. The intuitive handling of this unit is mainly due to its functional design, which features a pair of claws that rotate in the cylinder with no contact or wear. Its separate gearbox prevents oil contamination. The design ensures short downtimes and long service intervals: 20,000 hr between oil changes and up to 48,000 hr between general overhauls.
Learn more.

DualVee linear guides and tracks used in warehousing

See how Bishop-Wisecarver's DualVee^® motion tech can add huge benefits to warehousing operations. This video highlights two applications: a manual storage and retrieval system and an automated storage and retrieval system of long aerospace-grade carbon fiber in sub-zero temps. Patented DualVee guides and tracks keep operations running smoothly.
View the video.

Build-to-order knobs and hand hardware

Rogan Corp.'s innovative use of two-shot plastic injection and insert molding has been providing customers with high-quality plastic clamping knobs, levers, and control knobs for almost 90 years. Rogan offers concurrent engineering, product design, and assistance in material selection to ensure customer satisfaction for standard or customized parts, with a focus on cost optimization and on-time delivery. Custom colors, markings, decorative inlays, or engineered materials to meet special requirements, such as adding extra strength or utilizing flame-retardant material, are all offered.
Learn more.

Slewing ring bearing made of wood and plastic

The PRT-02-30-WPC slewing ring bearing is another step forward by igus toward integrating renewable raw materials into industrial production. Made of 50% wood and 50% high-performance plastics, the cost-effective and lubrication-free slewing ring bearing balances strength and durability with a proven low CO2 footprint. The materials incorporate solid lubricants, making the new slewing ring bearing smooth running and maintenance-free.
Learn more.

Flex Locators for quick fixture changeover

Flex Locators from Fixtureworks are designed for quick changeover of small and large fixtures, automation components, and more. They are ideal for applications that require frequent disassembly, providing excellent repeatability for locating and clamping in a single operation. Manual and pneumatic versions are available. Just turn the handle, knob, or screw!
View the video.

A metal that behaves like water: Graphene exhibits out-of-this-world characteristics

In a new paper published in Science, researchers at the Harvard and Raytheon BBN Technology have advanced our understanding of graphene's basic properties, observing for the first time electrons in a metal behaving like a fluid. [Credit: Peter Allen/Harvard SEAS]

 

 

 

 

Graphene is going to change the world -- or so we've been told.

Since its discovery a decade ago, scientists and tech gurus have hailed graphene as the wonder material that could replace silicon in electronics, increase the efficiency of batteries, the durability and conductivity of touch screens, and pave the way for cheap thermal electric energy, among many other things.

It's one atom thick, stronger than steel, harder than diamond, and one of the most conductive materials on Earth.

But, several challenges must be overcome before graphene products are brought to market. Scientists are still trying to understand the basic physics of this unique material. Also, it's very challenging to make -- and even harder to make without impurities.

In a new paper published in Science, researchers at the Harvard and Raytheon BBN Technology have advanced our understanding of graphene's basic properties, observing for the first time electrons in a metal behaving like a fluid.

In order to make this observation, the team improved methods to create ultra-clean graphene and developed a new way to measure its thermal conductivity. This research could lead to novel thermoelectric devices as well as provide a model system to explore exotic phenomena like black holes and high-energy plasmas.

This research was led by Philip Kim, professor of physics and applied physics in the John A. Paulson School of Engineering and Applied Sciences (SEAS).

An electron super highway
In ordinary, three-dimensional metals, electrons hardly interact with each other. But graphene's two-dimensional, honeycomb structure acts like an electron superhighway in which all the particles have to travel in the same lane. The electrons in graphene act like massless relativistic objects, some with positive charge and some with negative charge. They move at incredible speed -- 1/300 the speed of light -- and have been predicted to collide with each other 10 trillion times a second at room temperature. These intense interactions between charged particles have never been observed in an ordinary metal before.

The team created an ultra-clean sample by sandwiching the one-atom thick graphene sheet between tens of layers of an electrically insulating perfect transparent crystal with a similar atomic structure of graphene.

"If you have a material that's one atom thick, it's going to be really affected by its environment," said Jesse Crossno, a graduate student in the Kim Lab and first author of the paper. "If the graphene is on top of something that's rough and disordered, it's going to interfere with how the electrons move. It's really important to create graphene with no interference from its environment."

The technique was developed by Kim and his collaborators at Columbia University before he moved to Harvard in 2014 and now have been perfected in his lab at SEAS.

Next, the team set up a kind of thermal soup of positively charged and negatively charged particles on the surface of the graphene, and observed how those particles flowed as thermal and electric currents.

What they observed flew in the face of everything they knew about metals.

A black hole on a chip
Most of our world -- how water flows (hydrodynamics) or how a curve ball curves -- is described by classical physics. Very small things, like electrons, are described by quantum mechanics, while very large and very fast things, like galaxies, are described by relativistic physics, pioneered by Albert Einstein.

Combining these laws of physics is notoriously difficult, but there are extreme examples where they overlap. High-energy systems like supernovas and black holes can be described by linking classical theories of hydrodynamics with Einstein's theories of relativity.

But it's difficult to run an experiment on a black hole. Enter graphene.

When the strongly interacting particles in graphene were driven by an electric field, they behaved not like individual particles but like a fluid that could be described by hydrodynamics.

"Instead of watching how a single particle was affected by an electric or thermal force, we could see the conserved energy as it flowed across many particles, like a wave through water," said Crossno.

"Physics we discovered by studying black holes and string theory, we're seeing in graphene," said Andrew Lucas, co-author and graduate student with Subir Sachdev, the Herchel Smith Professor of Physics at Harvard. "This is the first model system of relativistic hydrodynamics in a metal."

Moving forward, a small chip of graphene could be used to model the fluid-like behavior of other high-energy systems.

Industrial implications
So we now know that strongly interacting electrons in graphene behave like a liquid -- how does that advance the industrial applications of graphene?

First, in order to observe the hydrodynamic system, the team needed to develop a precise way to measure how well electrons in the system carry heat. It's very difficult to do, said co-PI Dr. Kin Chung Fong, scientist with Raytheon BBN Technology.

Materials conduct heat in two ways: through vibrations in the atomic structure or lattice; and carried by the electrons themselves.

"We needed to find a clever way to ignore the heat transfer from the lattice and focus only on how much heat is carried by the electrons," Fong said.

To do so, the team turned to noise. At finite temperature, the electrons move about randomly: the higher the temperature, the noisier the electrons. By measuring the temperature of the electrons to three decimal points, the team was able to precisely measure the thermal conductivity of the electrons.

"Converting thermal energy into electric currents and vice versa is notoriously hard with ordinary materials," said Lucas. "But in principle, with a clean sample of graphene there may be no limit to how good a device you could make."

Source: Harvard John A. Paulson School of Engineering and Applied Sciences

Published February 2016

Rate this article