Milling Lexicon

This small lexicon was compiled to provide you with information about milling and our core production areas aerospace, medical engineering and mechanical engineering. Have fun reading!

Agenda:

Milling

During milling individual swarf are lifted off the processed material by special tools on so-called milling machines. Almost all materials, such as e.g. wood, plastics and most metals can be processed on these processing centers. The focus of most milling processes is metal processing, as this process can produce high-precision components, which are sturdy and resilient. Today’s milling machines come in different dimensions and qualities. State-of-the-art processing centers can simultaneously operate five axes and thus meet almost all workpiece shape requirements. Due to strong friction very high temperatures are often generated during milling requiring cooling.

Milling techniques

Milling is a generic term combining many different cutting technologies. It belongs to "cutting" and is divided into different process technologies. In general, process technologies are governed in DIN 8580; milling specifically in DIN 8589, part 3.

Different milling technologies are:
Face milling - flat surfaces are generated
Water jet milling - a high pressure water jet cuts not to hard materials (e.g. concrete)
Hob milling - the milling tool consists of a roller with individual teeth (mainly for milling of gear wheels
Profile milling - the contour of the clamped milling tools is directly transferred to the workpiece
Spiral milling - used together with profile milling for spindle production
Circular milling - mainly used for cylindrical surfaces
Form milling - any 3D surface can be milled
Plunge-cut milling - especially suitable for large depths

CNC milling

CNC is short for "Computer Numerical Control". Using this technique, the experienced CNC milling engineer can define control and feedback loop control of respective tool machines via computer programming. This cutting method was introduced approx. in the mid-seventies and has been and is still continuously improved. Today the CNC milling engineer programs the processing center using a commercially available PC with dedicated programs and interfaces, so that the requested tool can be manufactured without any further intervention. Milling machines change requested cutting tools and their positions as programmed. State-of-the-art milling machines are capable to load any cutting tool in progressively shorter times and increasing accuracy, to exactly determine the tool positions and to cut almost any material using five axes. In case of five-axis machines, the tool arm can usually move in three different axes, and the workpiece table, on which the workpiece is loaded, can move in additional two axes. Different programming processes and types are available. CNC milling is well established in the market and will be the solution for some time in the future, as it provides a relatively simple process to manufacture complex components with high repeatability and at high speeds. As they are cut from one piece, theses components exhibit high strength and rigidity. They can be well manufactured in series production using the available programming and program storage.

Differences to turning

The difference between milling and turning can be simply explained: in the case of milling the tool is rotating (and the workpiece is quasi stationary). In case of turning the workpiece is rotating (and the tool is stationary mounted). Some machines - so-called turning/milling machines - support both applications at the same time -however not with the same degree of sophistication.

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Mechanical Engineering

Mechanical engineering, besides perhaps construction engineering, is a classic engineering discipline and represents a large industrial field. Mechanical engineering or its branches are involved in the assembly of almost all products available today - even most food articles. Mechanical engineering is based on physics, which has a long history. For example, the wheel, which is already very old, can be addressed as a workpiece (without it no production would run today). Mechanical engineering includes not only classical fields of mechanics, thermodynamics and material science, but also fluid mechanics, drive technology, measuring and control technology and design technology, and many more. In order to manufacture a product of mechanical engineering, an idea, draft, design, calculation, construction, research, production and finally sales are required. Thus, mechanical engineering represents the core of any modern economy and is responsible for many jobs. Without mechanical engineering or a similar discipline civilization would most likely not be where it is today. This field is expanded on a daily base and driven by research and development. In Germany mechanical engineering has a long tradition and bloomed mainly due the strong automotive production. You can find product examples in our mechanical engineering area.

History

As mentioned above, the wheel and other very old inventions (pump, first gear) can be attributed to mechanical engineering. Up to the modern area machines were rather resources to generate unnatural effects than to support people.
Only in the Renaissance (late 14th century to 16th century) and with gifted persons such as Leonardo da Vinci, rethinking started. However, at that time engineering was still an art (artes mechanicae). With the acceptance of newly obtained knowledge in the age of Enlightenment, the first scientific discipline was developed - classical mechanics. Basic elements of mechanical system were researched and found: This includes rope, roll, rod, lever and the incline.
Industrialization initiated to most likely strongest push in mechanical engineering. Machines and automates were built to work faster and more economically, in order to move faster and to have an easier, more comfortable life. Consequently, casual, sometimes unpredictable human and animal actions could be converted in predictable activities calculable using algorithms.
At the end of the 20th century the machine itself is defined in the Machine Directive and mechanical engineering is known and respected as huge topic. The first turning lathes, dated approx. 550 B.C., have been significantly developed and improved. However, the principle remained the same. We still mill and turn today!

Fields

In the following, details are provided for several mechanical engineering fields.

Mechanics

Mechanics is the oldest field in physics and discusses statics and dynamics, which are divided into kinetics and kinematics. Topics such as time, velocity, length and acceleration, together with the movement of bodies in space and time are discussed and researched.

Production management

Addresses the application of production management. As the name indicates, management plays a huge role in this field and strong business administration influences can be recognized. Production management is often reduced to production industry and is divided into manufacturing industry and process industry. Ultimately, all process and manufacturing questions must be answered and sequences optimized.

Design engineering

Design engineering addresses design basics and their application. The customer has a certain request / a vision of a workpiece. What is the best way to put these thoughts onto paper or into the computer? This is often not an easy task, but one of the most important items for achieving an optimal product.

Manufacturing technology

Manufacturing technology is responsible to transform workpieces from provided materials into functional products using economical production. A product can be a semi-finished or finished product and corresponds to customer requests (incl. possible tolerances). Within manufacturing technology, individual processes are continuously developed, advanced and applied.

Automation technology

Automation technology targets automatic completion of tasks by machines and systems, hence without human interference. The higher the degree of automation, the less human interference is required. Thus, persons are relieved of exhausting or dangerous activities. In addition, performance is often improved, personnel costs reduced and quality improved. However, persons are frequently responsible for replenishment, monitoring and maintenance.

Material engineering

This field is also referred to as materials management. It addresses material characterization, research, development, processing and manufacturing. Materials are an important element of almost any education in the field of mechanical engineering. It mainly addresses different materials, which can be used in machines and systems - with their characteristics, advantages as well as disadvantages.

Measuring, control and feedback control systems

This mechanical engineering field addresses cybernetics, hence the automated control of dynamic systems without and with feedback loop. The versatile applications of these methods range from mechanical, over electronic to biological, chemical and social systems. First, technical problems are measured. Next, findings are converted into functional processes using control and feedback control.

Fluid technology

Fluid technology is the generic term for all processes, in which energy is transferred via fluid or gas flow. Fluid technology is applied in pneumatics and hydraulics.

Mechatronics

Mechatronics is the "link" between electronics, computer science and mechanics. This discipline started in precision engineering, computer science was added later. Mechanics and electronics define the core and use computer science as link. According to VDI Directive 2206, mechatronics describes "the synergistic interaction of the professional disciplines mechanical engineering, electrical engineering and information technology in design and fabrication of industrial products as well as in process design". Today mechatronics is widely used and comprises dimensions with more than ten orders of magnitude.

Vocational training

In Germany several vocational training options exist in mechanical engineering:

Technical school and technical college

In the German-speaking area, vocational training as mechanical engineer is traditionally of high importance. After vocational training in one of many companies in Germany, it is possible to attend a school to advance qualifications. In order to enter a technical college, professional vocational education and one year of practical training are required. If a candidate meets this requirement and passes the exam after four semesters at the technical college, he is awarded the title of "state certified mechanical engineer". In most German states it is also possible to specialize in certain professional fields during later semesters. A large number of diverse possible jobs and tasks exist within the extensive field of mechanical engineering. In all technical departments of a mechanical engineering company, such as development, design, planning, manufacturing control, quality management, etc. mechanical engineers are deployed as professional experts and managers.

College of higher education and university

At universities (mostly technical universities) and colleges of higher education, interested parties can obtain the academic degree of a graduate engineer (Dipl.-Ing or Dipl.-Ing (FH)) in the field of mechanical engineering. Due to the Bologna process and the associated conversion to the Bachelor / Master system in Germany, the number of offered German degree programs is reduced and the number of Bachelor / Master programs is increasing. In the meantime several individual programs, such as manufacturing technology, process engineering, mechanical engineering informatics, energy technology, aerospace, medical engineering and others have been established in the field of mechanical engineering. The prescribed period of study for a German degree program is 8 semesters, for a Bachelor 6 semesters and for an advanced Master degree is 4 months.

Dual education

Companies collaborate with universities, but mainly with colleges of higher education, to enable dual education. Learning in college is combined with practical work and experiences are accumulated. The goal is to combine the advantages of academic studies and vocational education.

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Aerospace

This part of engineering science addresses the development and operation of missiles, airplanes, spacecrafts and satellites. The objective is the continuous enhancement of the systems via best possible linking of individual components and subsystems. Among others, aircrafts should be as light, fuel-efficient, aerodynamic and affordable as possible and usable for different applications. This is researched and investigated on a daily base. You can find product examples in our aerospace area.

History

In the ancient world flying was often seen as privilege of the gods. People aspired to fly, which in the story of Daedalus and Icarus lead to death. People always wanted to fly and envied animals capable to fly. Thus, first inventors tried to use and copy nature, which so far has not been successful. First gliding flights over shorter distances were reportedly successful in the Middle Age. In Renaissance Leonardo da Vinci designed differed airplanes, but none of them was ever capable to fly. However, engineering mind and methodology were awakened. The first models capable of flying appeared end of the 17th and in 18th century. Famous names are George Cayley, Otto Lilienthal and the Wright brothers.

With the beginning industrialization the development was accelerated. Gliding turned into a sport between 1909 and 1911. The first motorized airplane in Europe without catapult system and without headwind started on November 12th, 1906.

We work on more information.

Fields

As explained above, the aerospace area addresses the development and operation of missiles, airplanes, spacecrafts and satellites. These systems are continuously advanced taking into account different aspects. For this purpose it is determined how new systems can be best integrated into already used elements.
This integration refers to e.g.:

• the aerodynamic shape,
• deployed and used equipment,
• engines and energy supply systems.
• the design of lightest possible aircrafts and
• base equipment subsystems, which ensure functionality and safety.

Wenz Mechanik GmbH is a manufacturer of small precision parts as well as large calibration tools for aerospace applications.

Vocational training

To just generically say something about vocational training in aerospace is presumptuous, as the field is enormous. Mechanical engineers, technicians, air controllers, pilots - all professions can be found in the aerospace field. Several vocational education options are available for most professions. We would like to recommend that interested parties review the options, focus on one field and then discuss with employees in the respective areas to benefit from their experiences. Often a university education is not absolutely necessary in order to reach a higher position. If you are interested in vocational education in the technical field, please refer to above point.

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Medical Engineering

Medical engineering is defined as the intersection between medicine and engineering science. Or simply said, technology rules and principles are applies to medicine. Doctors' professional knowledge and engineers' problem-oriented thinking are combined, in order to successfully use the resulting positive effects. The objective is to improve nursing practice, rehabilitation, diagnostics, therapy and life quality using new technologies and techniques. Without continuous improvement in medical engineering, many methods common today in the daily medical operation would not be feasible, and many people would suffer more. Medical engineering includes countless electrical devices known from hospitals and doctor's offices, as well as many small instruments, implants and special computer solutions developed e.g. in bioinformatics or medical informatics.

The medical engineering industry in Germany belongs to the largest and most advanced in the world, which mainly results from excellent education and vocational training. The largest and most known German manufacturer is "Siemens Healthcare". The largest company worldwide is "Roche" in Switzerland with more than three times the revenue of "Siemens Healthcare".

History

Medical engineering has existed for a long time. First findings of surgical procedures using special tools (based on bone findings) are dated in the Stone Age and the ancient world. Until academic medicine was introduced, the surgeon or barber-surgeon with mechanical training was responsible for small surgical procedures in the times of Romans and Egyptians. War played a very important role for the medical development, as a relatively large number of injuries occurred. In the past, instruments used for treatments or the doctor's hands were often not cleaned, frequently causing infections and the patient’s death. During that time the doctor's apron was often dark to avoid cleaning it too many times. Sterilization and disinfection of medical instruments played a very important role in the development. Another large step was the introduction of anesthesia in 1846. Prior to that, several patients died due to overpowering pain and shock during larger surgeries.

Based on technical developments former wood and stone instruments were replaced by delicate stainless steel or titanium instruments with different alloys and characteristics. The advantages of glass and, later on, of synthetic materials were recognized and added to the catalog of medical instruments and materials. In the second half of the 19th century the development of the first computer most likely introduced the largest revolution in medical engineering. A new category of medical-technical instruments was invented and increasingly extended up until now. To the latest accomplishments in medical engineering belong specialized software programs by linking bioinformatics or medical informatics, as well as artificial organ generation.

The introduction of many technical improvements also introduced immense costs, which are discussed over and over again - as it is currently the case.  Who should bear the costs? Are they still acceptable? Do medical engineering costs even significantly contribute to health care costs? Can costs be minimized? Of course, these costs must always be compared to the improved living standard and savings due to shorter treatment and sickness times.

Nevertheless, it is probably a fact that medical engineering will never disappear, as staying healthy is one of the basic needs of every person. Thus, any company (including Wenz Mechanik GmbH) operating in this field contributes to the general health condition of the population - even if it is only a small part.

Fields

The following fields belong to medical engineering:

Medical devices

Medical devices are divided into active and not active products and which are classified by four risk classes. Before a medical device is approved in the market, it must pass many tests and certifications. For this purpose an Act on Medical Devices is in effect in Germany, which is implemented according to an EU Directive.

Hospital technology

This sub-field is dedicated to medical devices in hospitals. The field covers device procurement and administration, as well as - legal as well as safety-related- monitoring and maintenance and application consultation for practicing doctors. The often extensive sterilization of devices and instruments is covered in this field as well.

Tissue engineering (TE)

The main goal of TE, which is a sub-field of regenerative medicine as well, is the creation of artificial organisms based on living cells. TE contains the following four elements: structural framework, living cells or tissue, signal transmission control to the living element, and an organism. The implants generated are also divided into four categories: originating in other living beings, from an individual of the same species, from the patient himself, from genetically identical individuals.
In the future another application of bio-technological production of in-vitro-flesh may be possible as well.

Imaging diagnostics

The most complicated, but also most used devices are devices used for imaging diagnostics. Different processes are available, which mainly differ in their image generation. This includes: ultrasound, radio nuclides, X-ray radiation, infrared radiation and nuclear magnetic resonance. Diagnostics requirements and finally the doctor decide which technology to apply.

Medical informatics

If the information technology used directly impacts the patient or could endanger the patient, the technology is included in medical engineering. This results in significantly higher product and software requirements. Examples are computer programs independently monitoring patients and independently interfering as needed. Advancing technology enables more and more in this segment as well.

Vocational training

In the following we only consider the profession of the medical engineer. Medical engineers are responsible and trained for planning, development, maintenance and sales of medical devices. Over the years different vocational training options have been developed and established in medical engineering. It is possible to obtain the qualification of a medical engineer by means of vocational training in a specialized company, or by graduating from college as Bachelor of Science and Master of Science for Medical Engineering (Dipl.-Ing. für Medizintechnik).

Medical engineer as apprenticed trade

A qualified vocational education in the metal or electrical field and appropriate advanced education is the prerequisite for the profession of the medical engineer. This can be achieved by showing several years of professional experience with medical devices or by completing two years of continuing education at a technical school, in order to achieve the certificate of a certified engineer (medical engineering).

Medical engineer as graduate degree

Currently the old German degree program is converted into the new Bachelor / Master program. With the increasing necessity of cross-functional education in this field, the possibilities for first-year students increase as well. Later on, specialization in one of the offered directions is possible. It may also occur, that medical engineering is offered as a specialization within the scope of engineering programs.
We recommend contacting universities and colleges for more detailed information regarding graduate programs in medical engineering. They are better informed regarding permanent changes and can provide detailed information.

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Quality standards

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We continuously work to extend this small lexicon and provide more information to you!