The real world meets the technical drawing curriculum

The real world meets the technical drawing curriculum

by Frank Saccente

In light of the difficulty faced by educators when trying to stress upon students the importance of academic curricula, an approach employed by a Technical Drawing program reveals some innovative methods for accomplishing this objective.

The approach has been employed in the Technical Drawing program at Roselle Park High School in New Jersey for the past five years and encompasses the traditional drafting curriculum, but with a very different twist. The program couples the normally covered areas of a drafting curriculum with exposure to "real life," out-of-school examples of its application. Here's how it's done.

By skimming the table of contents of any drafting text and then exercising some creativity and imagination, numerous opportunities can be found for bringing the curriculum to life in a fresh and exciting way and integrating it with other academic disciplines. Examples of such an approach follow below.

* Aerodynamics and CAD

In a unit entitled The Physics of Flight, Roselle Park High's drafting students are first familiarized with the principles and concepts responsible for creating lift in an airfoil or airplane wing. For those who don't hold a degree m aeronautical engineering, this phenomenon is explained through such physics principles as the Venturi Effect, Bernoulli's Law and Newton's Third Law of Motion. After the initial introduction, students then conduct library research to gather information on the above principles and are asked to define some common aeronautical engineering terminology.

Next, a model-making exercise is provided in which students apply the above concepts and terms to generate fiat, stretchout patterns for various types of paper airplanes. Students use the AutoCAD computer-aided drafting program to generate their paper airplane patterns and to add graphics and personalized text before outputting the pattern to a Houston Instruments' DMP 52 plotter.

The accuracy obtainable through a high-end CAD system such as this enables students to not only develop accurate multi-scaled patterns, but also helps them make wing surface-area calculations. These area calculations are then used during "test flights" of their paper prototype airplanes in the corridor, to determine when and if an increase in wing surface area leads to an increase in flight stability and duration.

Now it's time for the real-life example. This was accomplished by arranging to have the United States Coast Guard land one of its search and rescue helicopters on the school's athletic field. During the course of a three-hour demo by the chopper's Coast Guard crew, students saw the real-world application of all of the principles and concepts that were covered in class.

The reinforcement and resultant retention of the subject matter by students through a dramatic field experience such as this is unparalleled in terms of a lasting impression. The chopper demo also provided an ideal venue to stress upon students the critically important role that math and science play not only in aircraft design, but also in every aspect of our day-to-day lives.

* Machine Drafting and Cars

Another area ripe for accessing a wealth of "real life" reinforcement is machine drafting. This topic is typically covered in high school drafting programs and usually requires students to generate drawings of what they perceive to be meaningless, abstract shapes. In spite of its importance, it's tough to get a high school adolescent excited about a roller bearing and pulley assembly. But there is a better way.

Instead, through a unit entitled Automotive Concepts and Technology, Roselle Park students switch from the mundane task of creating drawings of abstract machine parts to delving into the much more interesting and numerous concepts associated with automotive design, engineering and manufacturing. This area is easily laced with math and science principles and concepts. For example, the calculation of horsepower provides an excellent vehicle for exposing students to the mathematical formula used to determine the volume of a piston cylinder; similarly, the physics involved in converting reciprocal motion into rotary motion is easily understood when related to a crankshaft and piston assembly. Compression ratios are a natural discussion area, as is the chemistry behind varying volatility levels of different octane gasolines. In terms of generating ideas for integrating math and science into the drafting curriculum, the automotive world would have to be considered the "mother lode."

A hands-on experience is provided through an abstract machine exercise in which students once again employ AutoCAD in a number of different ways. First, when drawing cam patterns that will later be used to fabricate working prototype cams, the extremely complicated and ...

The Importance of Technical Drawing to an Engineer

By Brad Painting, eHow Contributor
Image from advanced CAD program
Image from advanced CAD program
Image by Flickr.com, courtesy of Jeremy Levine

Without technical drawings, engineering would be a discipline of enormous guesswork. Technical drawings allow engineers to create designs, calculate forces and stresses on structures, and work with manufacturers. The ability to understand and work with technical drawings will not make someone a good engineer, but it is a necessary skill on the way to becoming adept in the profession.

Creating Designs
1. Engineers often create original designs that must be presented to others. Even if you can make a drawing understandable to yourself, it will not be readable to others if it does not follow the conventions of technical drawing. Engineers may design machine parts, composite structures or circuits that will involve the collaboration of several people. It is fine to sketch your basic ideas by hand while creatively brainstorming, but the details of the design must eventually be cemented into a format that is mutually understood.
Reading Designs
2. Engineers may not actually create designs, but analyze or perform calculations on them. A common example involves the calculation of the maximum stress on a machine part. By gathering the materials, geometry, and forces on a part from an engineering drawing, the engineer runs calculations to determine whether it will fail due to internal shear, compressive or tensile stresses.
Modifying Designs
3. Designs are rarely perfect the first time around, and usually involve an iterative process of modifying several factors. An engineer may work with a team by modifying the dimensions, geometry, materials or couplings to meet goals for safety, value and functionality. As an example, an engineer might be given the task of reducing the weight of an object by 5 percent without detracting from its functionality. A technical drawing is the only way to show exactly how the design would change.
Manufacturing
4. A technical drawing can give machine operators information on how to manufacture an item. It is the engineer's responsibility to create the design in a way that does not call for excessively difficult or complex manufacturing processes. An engineering drawing should contain sufficient views and acceptable surface finishes, tolerances and geometries to be manufactured with the available equipment.
Computer Software
5. Technical drawings are created and modified through a number of computer-aided design programs, such as AutoCAD and SolidWorks. These programs have long moved past cutting-edge status and are now practically considered a standard part of an engineer's skill set. To use these programs effectively, one must understand the different line types, views, dimensions and information included in technical drawings.


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Drafting As An Art Of Technical Drawing

Drafting is also known as technical drawing, it is the method of creating drawing for architectures and engineering. A person who is skilled in this field is more popularly known as a draftsman.

The fundamentals of drafting are easy. To be able to draft something, a draftsman places a piece of paper (or other drawing material) on any surface that has straight sides and right angle corners (drafting table).

Another tool needed for drafting is a t-square. A t-square is a ruler-like tool that slides on a straight edge, making it easier for a draftsman to move his/her tool on the drafting table.

The t-square enables its users to draw parallel lines by moving this tool and running your pencils edge along its straight edge line.

T-squares can also be used to hold other drafting devices like a set of squares or triangles. This way, the right angle of the t-square plus the angle of the triangle can create a perfect straight and angled line onto your paper.

Modern day drafting tables now come equipped with parallel ruler supported by both sides of the table. This ruler can also slide through your drafting table, assuring you that parallel lines that you draw are going to turn out parallel.

Other drafting tools are used to create circles and curves. A primary tool used in drafting is the compass. This instrument is used to create simple circles in your drawing.

A French curve on the other hand, is a plastic curved ruler that helps create simple and complex curves for your project. For more intricate curves, a spline is a drafting tool that is made of an articulated metal covered in rubber to enable users to bend this tool in different curves.

The simplest drafting system needs to pay full attention to the placement of tools and the accuracy of the table. The most common mistake in drafting is to let the triangle push the top of the t-square slightly down. When this happens, it will throw off all the proper angles in your drawing.

Another common problem in the area of drafting is the difficulty in drawing two angled lines and making them meet at a point. Because this was such a tedious task, the introduction of the "drafting machine" came into the light of possibility.

This machine makes it possible for the draftsman to have a precise angle wherever part of the paper he wishes to draw at. He does this with the help of the pantograph.

A pantograph is a special mechanical tool connected to the drafting table that when used to draw, it moves in a fixed relation to every other element of itself. Also, one major advantage of the drafting machine enables the ability to modify angles, thus eliminating the use of triangles.

Drafting must seem easy to most people, but to be able to draft something, it requires a certain knowledge in engineering.

For a time, drafting was a sought after profession in the United States, considering that the draftsman was a very skilled at his craft. But because of the creation of the drafting machine, drafting has become fully automated and largely accelerated using computer aided design or CAD.

An innovation of CAD is the less recognized CADD or computer aided design and drafting. Although this may be the case, skilled draftsmen may still be of use to some who need routine changes to their drawings.

Drafting is an art common to architects, engineers, or machinist. Some of the uses of drafting are for birds eye view, elevations, plan view, isometric projections, cross sections and the like.

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Mechanical engineering

From Wikipedia, the free encyclopedia
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Mechanical engineers design and build engines and power plants...
...structures and vehicles of all sizes.

Mechanical engineering is a discipline of engineering that applies the principles of physics and materials science for analysis, design, manufacturing, and maintenance of mechanical systems. It is the branch of engineering that involves the production and usage of heat and mechanical power for the design, production, and operation of machines and tools.[1] It is one of the oldest and broadest engineering disciplines.

The engineering field requires a vast understanding of core concepts including mechanics, kinematics, thermodynamics, materials science, and structural analysis. Mechanical engineers use these core principles along with tools like computer-aided engineering and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, motorized vehicles, aircraft, watercraft, robotics, medical devices and more.

Mechanical engineering emerged as a field during the industrial revolution in Europe in the 19th century; however, its development can be traced back several thousand years around the world. The field has continually evolved to incorporate advancements in technology, and mechanical engineers today are pursuing developments in such fields as composites, mechatronics, and nanotechnology. Mechanical engineering overlaps with aerospace engineering, civil engineering, electrical engineering, and petroleum engineering to varying amounts.

Development

Applications of mechanical engineering are found in the records of many ancient and medieval societies throughout the globe. In ancient Greece, the works of Archimedes (287 BC–212 BC) deeply influenced mechanics in the Western tradition and Heron of Alexandria (c. 10–70 AD) created the first steam engine.[2] In China, Zhang Heng (78–139 AD) improved a water clock and invented a seismometer, and Ma Jun (200–265 AD) invented a chariot with differential gears. The medieval Chinese horologist and engineer Su Song (1020–1101 AD) incorporated an escapement mechanism into his astronomical clock tower two centuries before any escapement can be found in clocks of medieval Europe, as well as the world's first known endless power-transmitting chain drive.[3]

During the years from 7th to 15th century, the era called the Islamic Golden Age, there have been remarkable contributions from Muslim inventors in the field of mechanical technology. Al-Jazari, who was one of them, wrote his famous Book of Knowledge of Ingenious Mechanical Devices in 1206, and presented many mechanical designs. He is also considered to be the inventor of such mechanical devices which now form the very basic of mechanisms, such as the crankshaft and camshaft.[4]

Important breakthroughs in the foundations of mechanical engineering occurred in England during the 17th century when Sir Isaac Newton both formulated the three Newton's Laws of Motion and developed calculus. Newton was reluctant to publish his methods and laws for years, but he was finally persuaded to do so by his colleagues, such as Sir Edmund Halley, much to the benefit of all mankind.

During the early 19th century in England, Germany and Scotland, the development of machine tools led mechanical engineering to develop as a separate field within engineering, providing manufacturing machines and the engines to power them.[5] The first British professional society of mechanical engineers was formed in 1847 Institution of Mechanical Engineers, thirty years after the civil engineers formed the first such professional society Institution of Civil Engineers.[6] On the European continent, Johann Von Zimmermann (1820–1901) founded the first factory for grinding machines in Chemnitz (Germany) in 1848.

In the United States, the American Society of Mechanical Engineers (ASME) was formed in 1880, becoming the third such professional engineering society, after the American Society of Civil Engineers (1852) and the American Institute of Mining Engineers (1871).[7] The first schools in the United States to offer an engineering education were the United States Military Academy in 1817, an institution now known as Norwich University in 1819, and Rensselaer Polytechnic Institute in 1825. Education in mechanical engineering has historically been based on a strong foundation in mathematics and science.[8]
[edit] Education

Degrees in mechanical engineering are offered at universities worldwide. In Bangladesh, China, India, Nepal, North America, and Pakistan, mechanical engineering programs typically take four to five years of study and result in a Bachelor of Science (B.Sc), Bachelor of Technology (B.Tech), Bachelor of Engineering (B.Eng), or Bachelor of Applied Science (B.A.Sc) degree, in or with emphasis in mechanical engineering. In Spain, Portugal and most of South America, where neither BSc nor BTech programs have been adopted, the formal name for the degree is "Mechanical Engineer", and the course work is based on five or six years of training. In Italy the course work is based on five years of training; but in order to qualify as an Engineer you have to pass a state exam at the end of the course.

In Australia, mechanical engineering degrees are awarded as Bachelor of Engineering (Mechanical). The degree takes four years of full time study to achieve. To ensure quality in engineering degrees, the Australian Institution of Engineers accredits engineering degrees awarded by Australian universities. Before the degree can be awarded, the student must complete at least 3 months of on the job work experience in an engineering firm.

In the United States, most undergraduate mechanical engineering programs are accredited by the Accreditation Board for Engineering and Technology (ABET) to ensure similar course requirements and standards among universities. The ABET web site lists 276 accredited mechanical engineering programs as of June 19, 2006.[9] Mechanical engineering programs in Canada are accredited by the Canadian Engineering Accreditation Board (CEAB),[10] and most other countries offering engineering degrees have similar accreditation societies.

Some mechanical engineers go on to pursue a postgraduate degree such as a Master of Engineering, Master of Technology, Master of Science, Master of Engineering Management (MEng.Mgt or MEM), a Doctor of Philosophy in engineering (EngD, PhD) or an engineer's degree. The master's and engineer's degrees may or may not include research. The Doctor of Philosophy includes a significant research component and is often viewed as the entry point to academia.[11] The Engineer's degree exists at a few institutions at an intermediate level between the master's degree and the doctorate.
[edit] Coursework

Standards set by each country's accreditation society are intended to provide uniformity in fundamental subject material, promote competence among graduating engineers, and to maintain confidence in the engineering profession as a whole. Engineering programs in the U.S., for example, are required by ABET to show that their students can "work professionally in both thermal and mechanical systems areas."[12] The specific courses required to graduate, however, may differ from program to program. Universities and Institutes of technology will often combine multiple subjects into a single class or split a subject into multiple classes, depending on the faculty available and the university's major area(s) of research.

The fundamental subjects of mechanical engineering usually include: