Comments (0)

By admin, May 16, 2012 12:27 pm

The term ‘rare earth metals’ or ‘rare earth elements’ (REEs) is misleading since these metals are not that rare. Cerium is as common as copper in the earth’s crust. Nevertheless, between 2010 and January 2012 prices for rare earth metals rose sharply. This had a large impact on design and engineering as rare earth metals are commonly used to make permanent motors (PM).

The usefulness of such rare earth elements as neodymium and dysprosium is that they can be used to make high-flux permanent magnets that tolerate extreme temperatures without demagnetizing.

The magnetic field produced from rare earth metals often exceeds 1.4 Teslas. In contrast, ferrite magnets produce a magnetic field of just 0.5 to 1 Tesla.

Due to this greater strength and the lightweight nature of rare earth magnets prior to 2008 they were used for a variety of purposes such as computer hard drives, wind turbine generators, audio speakers, magnet motors in cordless equipment, Mag-Lev trains and many other products.

Such is the strength of economics to impact upon design that as rare earth metals become more expensive ways had to be found to replace permanent magnets with alternative technology.

There are plenty of engineering solutions possible such as AC induction motors, AC converter drives and switched reluctance (SR) systems. AC inverters work well with fans and pumps.

SR motors don’t use carbon brushes, commutators or magnets. Rather the rotor position is detected using a sensor. This tells which stator to energize to make the rotor turn through 360 degrees. SR motors could be used in the automotive industry and in making fridges and other white goods. The technology behind SR motors has been slow to develop because of the comparatively cheap prices of rare earth metals.

Now in May 2012 prices have dropped slightly for rare earth metals. It has come out that speculators were artificially driving up prices while the blame was wrongly attributed to lower Chinese quotas. Here is a clear example of how economics has a direct bearing on engineering and design.

Comments (0)

By admin, May 7, 2012 11:26 am

The importance of Nikola Tesla’s contribution to the development of electrical power was long overshadowed by the pre-eminence of Thomas Edison. They were rivals at the time for the glory that electrical inventions would bestow on the scientist credited with bringing electricity to the world. Their rivalry caused the battle of the currents. Edison promoting DC electrical power plants and Tesla promoting his own newly invented AC technology for power plants.

Edison’s DC power generation system required for power plants to be close to urban centers because electrical power was lost over distance. This was not ideal at a time when coal was burnt to generate electricity. Tesla understood that this was a wasteful idea. Whereas Edison designed a system where the supplier put out 110 volts and the consumer received 100 volts that was deemed ‘safe’, Tesla realized it was wasteful: with an AC electrical supply voltage load could be much higher and a step-down transformer could be used to lower the voltage for the end consumer. AC power lent itself to the easy implementation of step up and step down transformers.

This meant that electrical power could be produced in power stations many miles from the consumers of the electricity. This would reduce pollution in big cities.

It was entrepreneur and engineer George Westinghouse who backed Nikola Tesla. Initially the bad PR created by Edison concerning the safety of the high voltage AC system meant the war of the currents was won by DC. Edison even designed the first electric chair using AC power in Sing Sing Prison to show the world how literally deadly AC power was.

Tesla won the PR campaign in 1893 with the World Exposition in Chicago where in front of millions of people he passed high voltage AC power through his body to light up a light bulb and shot electricity into the audience using a Tesla Coil.

The battle of the patents was won. It was impractical to build power stations near all areas that needed electricity and the logistics of using different power lines for different strength voltages, and Tesla’s demonstration finally convinced the engineering community that AC was safe as well as better. With the building of the Niagara Falls hydroelectric power plant using AC generators that were to eventually to meet some of the huge demand of the New York metropolitan area Tesla won the Battle of the Currents.

It was an acrimonious battle between the two inventors. Tesla had emigrated from Europe where he had studied electrical engineering at Austrian Polytechnic at Graz. He started out working for Edison’s company first in Paris then in New York. As the much controversial story goes, Tesla was soon singled out by Edison as being particularly gifted. Edison is meant to have offered Tesla $50,000 to overcome the inherent problems with DC motors and generators. When Tesla did this but didn’t receive his promised financial reward he quit.

Not only does the world owe a huge debt of favor to Tesla because of AC electricity but also for his work on getting AC power to turn a motor. He found a way of using magnetic forces to make a motor turn revolutions rather than go continually clockwise / anti clockwise as the current alternated. This is the basis for modern engine commutators.

People are mistaken in the notion that Mancini invented the radio. Tesla had already demonstrated the principle behind wireless transmission nearly 10 years prior to Mancini’s invention. Tesla wrote in “Century Magazine” in 1900: “…that communication without wires to any point of the globe is practicable.” Also in 1900 J.P Morgan gave Tesla $15,000 to build a radio tower to transmit pictures, reports and weather information. J.P Morgan shut the project down when it was discovered that the tower would give free energy.

Throughout his career Tesla was looking to the future. In his time he probably had a clearer view of the potential of wireless communication than any of his contemporaries. He was in sharp contrast to Edison in being motivated by philanthropy rather than the profit motive. None who met him doubted his genius. He was eidetic and a polyglot. Sadly, Tesla had what would be termed today as ‘obsessive-compulsive’ disorder and spent his last few years as a recluse living in a New York hotel. He became the archetypal ‘mad professor’. The story has it that the mutual contempt between Edison and Tesla meant that both man would share the Nobel Prize with the other, and as a result neither got it.

It was only in the Twentieth Century that Tesla was to emerge in his rightful place in the history of electrical engineering.

Further Reading:

Tesla versus Edison

Comments (0)

By admin, May 2, 2012 4:12 pm

‘Bio-inspired’ is short for ‘biology inspired’. It is a growing field for design and engineering that covers a diverse range of disciplines. It is essentially looking to nature, to biological forms for inspiration.

Medicine

Perhaps one of the most established forms of bio-inspired science is pharmaceuticals. For many years now scientists have been studying flora found in the Amazon and elsewhere for properties that can be replicated synthetically and turned into medicine. Estimates claim that only a small fraction of the bio resources have been studied in the Amazon rainforest and that scientists could yet find cures for major diseases such as cancer and HIV through bio-inspired medicine. The race is on to study the biology of the Amazon before the forest shrinks to a pitiful size due to illegal logging.

Adhesion

In February 2012 Oxford University announced that they had made a bio-inspired superglue that outperformed other traditional adhesives. The inspiration was Streptococcus pyogenes, a bacteria that lives in human’s throats and can sometimes lead to toxic syndrome or flesh eating disease. Scientists at Oxford University were drawn to the bacteria because of its protein which binds itself and forms a lock. The implications for this superglue are far-reaching as it could be used to assemble materials on a nano-scale thus furthering the possibilities of nanotechnology development.

Materials

Recently, scientists have been looking at silk worm cocoons. The material used by silkworms is very strong and yet lightweight. The design process is underway to make bio-inspired lightweight body armor and composite materials that could be used for car parts by mimicking silk worm cocoons.

Bio-inspired has also been taken into the arena of computing. It is an ethos of using biological systems for evolving computer intelligence. The traditional form of AI is a top-down approach where the programmer inputs data with the hope that the computer will display signs of intelligence. With bio-inspired computing it is bottom-up. Typically a computer will be given a set of rules and a set of simple organisms that follow the rules. After many iterations over generations complex behavior emerges that is often counter-intuitive. It is this type of evolving complex behavior that bio-inspired computing believes will evolve computer intelligence. This is another example of how the division between the digital world and the biological world is becoming more blurred.

Spider man suit

One product that is still in the research and development stage is the spider man suit. It sounds far-fetched but scientists at Lewis and Clarke College in the USA think it is possible thanks to discoveries made from studying geckos. These creatures have feet covered in minute hairs that deform to fit a surface so exactly that molecular attraction comes into play. This is known as van der Waals force. The suction of the gecko’s hairs depends on hairs per unit area. To get a similar ratio artificially carbon nanotubes were used. Using nanotechnology the suction has actually been improved. Adhesion 200 times stronger than gecko’s hairs has been accomplished.

It is just a matter of time before a commercially viable product is found to match this new bio-inspired technology. Whether it is a spider man suit or gloves we will have to wait and see.

These are just a few examples of an exciting new field. Scientists have always been inspired by nature – think of the apple that fell into Newton’s lap – but now the tools and analytical skills are emerging to truly imitate and improve on nature.

Sources and Reading

1) Bio-inspired superglue from flesh eating bacteria
2) Hard composite material from silkworm cocoon
3) Bio-inspired computing

Comments (0)

By admin, April 30, 2012 9:34 pm

Even if you are ignorant of the math behind the Golden Ratio you will nevertheless immediately recognize its importance. It is an ancient mathematical formula that is meant to be based on observation of nature regarding the ratio of lengths and angles in shapes. It is found that the golden ratio crops up everywhere. It is felt to be inherently ‘right’ from a design point of view. It is for this reason that design makes heavy use of the golden ratio. It can be seen in the rectangles of playing cards, postcards, white boards and tables. Regular pentagons, decagons and dodecahedrons all contain the golden ratio. Being aware of the golden ratio is fundamental for a designer wishing to make a pleasing aesthetic impact.

The golden ratio can be explained mathematically as follows:

To break this down, the ratio is 1.61803399.

It was Euclid (c. 325–c. 265 BC) who made the first written reference to the golden ratio. He called it ‘extreme and mean ratio’. It is thought by historians that the golden ratio was grasped earlier as the Parthenon in Athens appears to be a homage to the golden ratio. Many great mathematicians, philosophers and thinkers have worked on the math involved in the golden ratio as well as speculated on the possible meanings of the ubiquity of the formula.

The first person to give us the golden ratio as a fraction was Michael Maestlin (1550–1631). It was Johannes Kepler (1571–1630) who proved the connection between the golden ratio and the Fibonacci sequence.

Today graphics designers, architects and website designers heavily use the golden ratio for curves, rectangles and proportions between compositional parts. The Nissan logo, the Toyota logo and many others are based on the golden ratio. The size of text on the page of a typical book is the golden ratio. The off-center detail of many photographic compositions is based on the swirl given by the golden ratio. The spacing of columns on a webpage is often down to the golden ratio.

Once understood the golden ratio jumps out at you as you go about your day. Some would argue that it is essence of good design.

Further Reading

About the maths behind the golden ratio – wikipedia
About how the golden ratio is applied to good website design – www.webdesignstuff.co.uk

Comments (0)

By Engineer 1, April 27, 2012 10:28 am

There are 5 metrics to be considered when choosing the most suitable type of graphite for an electrical discharge machining (EDM) operation. EDM is a process where a high voltage is sent between 2 electrodes that are in close proximity but that are not touching. Many thousands of sparks are given off per second between the electrodes that erode or cut. The process occurs in the medium of a dielectric liquid. One of the electrodes will be the ‘work piece’. This is a conductive metal or alloy that is going to be cut to shape. The other electrode is the graphite electrode that needs to be chosen carefully for suitability for the EDM operation.

Wear Resistance

Electrode wear can be measured by end wear, side wear and corner wear. Since corners and edges are the most susceptible parts of the electrode to wear these are usually used to decide on acceptable wear resistance.

Surface Finish

Surface finish can be adjusted in 2 ways:

1)    Adjusting machine settings
2)    Choosing finer grain sized graphites.

Metal Removal Rate

Both the metal being cut and the graphite electrode are considered ‘electrodes’ in the EDM process. To ensure that the metal erodes faster than the graphite electrode 2 things can be done:

1)    Best machine settings
2)    Correct graphite / work piece combination

Machinability

All graphites are relatively easy to machine compared to metals. However, strength and grain size make some materials more machinable than others.

Material Cost

The unit cost of electrodes is a small part of the total cost of a job. The important considerations when pricing a job are:

1)    Electrode fabrication time
2)    Metal removal rate
3)    Electrode wear

The selection of the right graphite for the job greatly influences profitability. For this material specifications need to be studied. Advice should be taken from sales engineers for each job.

It is important to find a supplier of EDM electrodes that will help you to make the right decision about types of graphite electrodes to use for cutting. It is an essential part of the engineering process.

Information provided by Erodex (UK) Ltd.
www.erodex.com

Comments (0)

By admin, April 26, 2012 2:24 pm

The Industrial Revolution was ‘carbon based’ to the extent that locomotion was created by burning fossil fuels. First coal and then oil and gas. The early steam locomotives burnt coal to turn water into steam and drive a turbine. In the late 1800s and most of the 1900s nobody saw any problem with this basic carbon model for energy.

Then two problems became apparent. Firstly, that fossil fuel resources were finite. This had a strong impact on the geo-political landscape as it became clear that economic growth was tied to securing fossil fuel supplies which were controlled mostly by OPEC countries, especially those in the Middle East with radically different cultures to those found in North America and Europe. The second problem was carbon dioxide emissions. At the start of the Twenty-first Century scientists around the world (barring a few rogue skeptics) agreed that carbon dioxide emissions in the atmosphere were trapping the sun’s heat thus raising global temperatures. They also agreed that the amount of carbon in the atmosphere had exponentially shot up and that this must be due to human activity.

The solutions are to either abandon the current lifestyle many people enjoy with such things as cars, electricity, trains, TV, Starbucks and so on, or find a scientific and engineering solution to the current carbon based energy systems we rely upon.

Much work has already been done on alternative energy technology, clean energy technology and sustainable energy technology. There is nuclear power, wind turbine power, geo thermal energy and solar energy. All of these means of generating zero or low carbon power have their drawbacks.

Engineers are now looking at hydrogen as a replacement for carbon. The most promising solution so far is hydrogen fuel cells. These cells emit only water and some heat. The waste product of CO2 has been replaced by the waste product H2O.

The British company ACAL Energy has developed a system that replaces 80-90% of the expensive titanium used in fuel cells with a liquid catalyst. The catalyst has made the hydrogen fuel cell more efficient. This new technology is still very much in its infancy. ACAL Energy only employs 32 people and is subsidized by the not-for-profit UK Carbon Trust.

This is all good news. The only bum note is that hydrogen fuel cells are still too expensive to produce to be called ‘economically viable’. This is the challenge for engineers working in this field. If they succeed in making hydrogen fuel cell energy generation competitive with traditional carbon based energy generation we really could be entering the century of hydrogen.

Comments (0)

By admin, April 25, 2012 10:40 am

Isambard Kingdom Brunel was born in 1806. He was the son of an eminent engineer and was to grow up and become Britain’s most famous engineer. In 2002 a BBC poll placed Brunel as second in their 100 Greatest Britons program. When you look at the achievements in civil engineering and structural engineering of Isambard Brunel Kingdom it is easy to understand why the man continues to command such respect long after his death in 1859.

Brunel proved a genius from an early age. By 4 he was studying drawing and observational techniques. By 8 he had mastered Euclidean geometry. He went to Caen College followed by Lycée Henri-Quatre in Paris. After graduating his father wanted Brunel to study engineering but Brunel’s entry to the renowned École Polytechnique was blocked because he was a foreigner in France. Instead Marc Brunel sent his son to study under the famous clockmaker and horologist Abraham-Louis Breguet.

On joining his father’s engineering company Brunel was involved in the ill-fated attempt to build a tunnel under the Thames River in London. Despite a shield invented by his father to protect the miners there were several collapses. Brunel risked his life to save trapped miners. In 1828 there was a serious accident that killed 2 miners and Brunel narrowly escaped with his life.

Brunel’s next project was much more auspicious. It was the engineering project that he is perhaps best remembered for – the Clifton Suspension Bridge: an elegant bridge spanning Avon Gorge linking Bristol with Leigh Woods. The bridge was not finished until after Brunel’s death.

In 1833 Brunel was appointed the chief engineer of the Great Western Railway. In his work for the company he designed many bridges and railway stations. He completed the line from London to Exeter. He built the longest tunnel at the time in the world for one stretch of railway. It was at this point Brunel started to become famous. His drive, ambition and innovative solutions to long standing engineering problems marked him out as being on the vanguard of the industrial revolution.

Brunel proposed that passengers in London should be able to buy one ticket to New York. His plan was to take train passengers disembarking at Bristol on a stream ship to America.

Work on the Great Western boat was finished in 1838. It was the longest boat in the world at the time. It used a new innovation in engineering – a steam engine that had a surface condenser so that it could run on salt water. The boat broke the record for the fastest transatlantic crossing – 15 days and 5 hours.

Brunel continued to work at a prodigious rate juggling commitments for railway companies and steamship companies. He even found time to design a hospital for the Crimean war that had basic temperature control. Following the observations of Florence Nightingale Brunel built Renkioi Hospital to maximize sanitation through systems of ventilation and drainage.

Brunel was a heavy smoker. He had a stroke just days before the maiden voyage of his Great Eastern steamship. He left behind a wife, 3 children and a vast legacy of engineering achievements many of which are still in use today.

Comments (0)

By admin, April 24, 2012 11:45 am

Since the advent of the computer age in the 1950s with such pioneer companies as IBM, Apple and then Microsoft there has been a manifold increase in the amount of different tasks covered under the labels of engineering and design.

There are those people who design and build computers using processors, integrated circuit boards etc. They are involved at the hardware level. Computer engineers have a unique skill set that is not covered by electrical engineering, although there is plenty of ground that is shared by both disciplines. Computer science and computer hardware engineering are interconnected and often serve as synonyms for each other.

With the increasing possibilities of nanotechnology there is likely to be new hybrid specializations perhaps in the order of nano-computer engineer. Nanotechnology is still in its infancy and it is too early to tell how it will impact on the job of computer engineers and designers.

Another group of engineers connected to the hardware of computers are those people who set up and run servers. These are banks of computers that store websites and other information that can be accessed through the internet.

Similarly there are engineers who set up the technology for computer systems and intranet for big companies. This is covered by the term IT engineer. This job could also be organizing cables that run under the sea and overland connecting the world together on the internet and by telephone. In this case civil engineering degrees are apposite to the task.

When it comes to software and website creation, new skills entirely are needed. Code engineers write software – namely programs that the consumer interfaces with. In the early days of computing computers could only be handled using languages such as BASIC. Nowadays coders write software and applications that are between the end user and the computer making it possible with no coding skills to manipulate a computer.

It is at the level of coding that hacking often occurs. Hacking has a bad name, but originally it referred to the idea of re-purposing. It was about getting into the code of a program and finding ways to re-use the code. That doesn’t have to be stealing credit card information.

The hacking issue as well as the ever-present computer virus issue has given rise to engineers who monitor security and safety of computers and information. In a way hackers and firewall engineers are two sides of the same coin.

Lastly, there is the business of designing websites. In many ways this overlaps with graphic design. Website designers will use HTML, php, JavaScript, Flash and other computer languages to create what they hope are attractive and easy-to-navigate sites. The job of website designers is slowly being eroded by WYSIWYG editors. This is an acronym that means ‘What You See Is What You Get’. Such editing programs include Adobe’s Dreamweaver. The WordPress interface uses dynamic php coding to let people with no coding experience make a website. As the number of ‘themes’ proliferate on WordPress the need for website designers seems to be receding.

Graphic designers and website designers have a certain niche in the creation of logos and other branding items. Making vector-based graphics is still not a skill that can be picked up in a few minutes; although as Adobe Illustrator and Photoshop continue to innovate that might not be the case for long.

Those website designers who make specific programs for online booking and financial tools using C, C++ computer languages (as well as other specialized languages) have more durability as big companies want tailored products that are managed.

It is apparent that the information revolution has led to the creation of many new types of engineering and design jobs. Such is the pace of change that several of these jobs are being made defunct by the ability of coders to make programs that allow the general public to do more and more things directly without having to pay an ‘expert’. This is a good thing. The Open Source Project to share code is increasing the power of computers to meaningfully help us.

Comments (0)

By admin, April 21, 2012 3:01 pm

When I studied civil engineering in university in the UK there were only 4 women in my year. They were very popular, and more importantly they all excelled at their studies and went on to have successful careers in engineering. Indeed most of the peers that I kept in touch with went on to land good engineering posts in their specific fields and over the years rose to highly paid positions.

Unlike law or medicine it doesn’t take several years to graduate. After 4 years studying you are an engineer and you can go out onto the job market place. There is no need for internships like in medicine and law. This makes engineering an attractive profession. It is thus somewhat of a mystery why more women don’t go into engineering.

In America the situation is the same. According to Wikipedia only 11% of the engineering workforce in America in 2003 was female. Women are chronically unrepresented in the present supposedly enlightened era in all fields of engineering. This is not due to a lack of equal rights or human rights. It is down to education and how engineers are perceived by society.

Secondary education in both the States and Europe is still failing women. It is full of hidden biases that are pushing women to study languages and the humanities. The old stereotype of boys playing with building blocks and girls playing with dolls seems to insidiously manifest itself throughout the schooling system.

What is needed is to highlight the female contributions made in the field of engineering. Role models are needed so that engineering doesn’t seem a male-only preserve.

Here are a few successful American women in engineering:

Kate Gleason

In 1893 Kate Gleason designed and built a machine that made beveled gears for her father’s factory. She was instrumental in making the factory one of the leading producers of gear cutting machines by the early 1900s. In 1914 Kate Gleason became the first fully elected female member of the American Society of Mechanical Engineers.

Helen Augusta Blanchard

She was known as ‘Lady Edison’. Helen Augusta Blanchard held 28 patents, most of which were connected to the sewing machine. She invented a machine that could make the zigzag stitch in 1873 that was to make her fortune.

Martha J. Coston

In 1859 Martha J. Coston patented signal flares that used firework technology. She was paid $20,000 for the patent by the navy. It is said that her flare system for communication helped the north win the civil war.

Olive Dennis

She was only the second women to graduate from Cornell University with a degree in civil engineering. She went to work for the engineering department for the Baltimore and Ohio Railroad. She made many improvements to passenger comfort on the carriages including patenting the ‘Dennis Ventilator’. Olive Dennis became the first female member of the American Railway Engineering Association.

Mary Walton

Mary Walton was an independent inventor who worked from her basement. She was concerned with air pollution and sound pollution in New York. She invented a system to pass factory emissions through water tanks that absorbed the pollution. The water was then drained into the city’s sewers. She also invented a system using cotton and sand to reduce the noise from train carriages. She sold the patent to New York City Metropolitan Railroad.

These are only 5 women who succeeded in the ‘man’s world’ of engineering. Their stories clearly show that women can be inventive, can solve problems thrown up by new technology, and most of all, that women make just as good engineers as men.

Further reading

A good resource is www.engineergirl.org

Comments (0)

By admin, April 19, 2012 2:57 pm

Computer Aided Design (CAD) or Computer Aided Design and Drafting (CADD) have revolutionized design since the mid-Twentieth Century. It is a computer program that has radically altered the work flow of designers. Previously, large teams of designers were needed to draft the drawings for the design of a new product. That is now a thing of the past thanks to CADD.

Designers at universities no longer have to learn how to draw designs on paper using protractor and compass. They must still learn the theory of geometrical design, but instead their education focuses on how to use a number of software programs to make virtual designs that can later be printed off if necessary.

CADD programs use vector graphics and raster graphics to visually simulate an object being designed either in a 2D or 3D space. Along with information regarding shape a CADD program can also give all the information regarding materials, processes, dimensions and tolerances according to the conventions of design and engineering. Thus, CADD can be used for the drafting of technical engineering drawings.

This technology has become vital to numerous sectors including aerospace design, automobile design and shipbuilding as well as industrial and architectural design. CAD is also behind the production of special effects in movies. Nowadays everything from shampoo bottles to new engines starts off as a CADD simulation.

If a program can create accurately a shape in 2D or 3D it is called a CAD program; if it can do this as well as create dynamic mathematical modeling it is referred to as a CADD program.

The seminal moment for the development of CAD and CADD programs is believed to be the invention of SKETCHPAD in 1963 by Ivan Sutherland. This early program allowed the designer to feed information into the computer using a light pen and CRT monitor. This technology is the precursor to the graphical user interface that is indispensible to modern computer design.

Another landmark in 1971 was the ADAM system (Automated Drafting and Machining) developed by Dr. P.J. Hanratty. He also supplied code to other companies working in the same field. From this point several small steps were taken until in the 1980s solid modeling was invented and led to a quantum jump.

AutoCAD was released in 1982; Pro/Engineer in 1988; SolidWorks in 1995; Intergraph in 1996; and Autodesk Inventor in 1999.

From a philosophical point of view CAD and CADD heralds the moment when man managed to make the most accurate model of nature in digital terms. The accuracy of computers far excels any hand drawings. Moreover, the ability to move digital renditions of objects in virtual space marks the first stage of the possibility of creating a digital world that we can interact with in a way that is existentially similar to living in the ‘real world’ – hence the fascination for science fiction writers in the possibilities of living in a virtual world; and being fooled by a virtual world.