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Precision engineering

Precision engineering

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Encyclopedia
Precision engineering is a subdiscipline of electrical engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

, electronics engineering, mechanical engineering
Mechanical engineering
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...

, and optical engineering
Optical engineering
Optical engineering is the field of study that focuses on applications of optics. Optical engineers design components of optical instruments such as lenses, microscopes, telescopes, and other equipment that utilizes the properties of light. Other devices include optical sensors and measurement...

 concerned with designing machines, fixtures, and other structures that have exceptionally low tolerances, are repeatable, and are stable over time. These approaches have applications in machine tool
Machine tool
A machine tool is a machine, typically powered other than by human muscle , used to make manufactured parts in various ways that include cutting or certain other kinds of deformation...

s, MEMS
Microelectromechanical systems
Microelectromechanical systems is the technology of very small mechanical devices driven by electricity; it merges at the nano-scale into nanoelectromechanical systems and nanotechnology...

, NEMS
Nanoelectromechanical systems
Nanoelectromechanical systems are devices integrating electrical and mechanical functionality on the nanoscale. NEMS form the logical next miniaturization step from so-called microelectromechanical systems, or MEMS devices...

, optoelectronics
Optoelectronics
Optoelectronics is the study and application of electronic devices that source, detect and control light, usually considered a sub-field of photonics. In this context, light often includes invisible forms of radiation such as gamma rays, X-rays, ultraviolet and infrared, in addition to visible light...

 design, and many other fields.

Overview


One of the fundamental principles in precision engineering is that of determinism. System behavior is fully predictable even to nanometer-scale motions.

"The basic idea is that machine tools obey cause and effect relationships that are within our ability to understand and control and that there is nothing random or probabilistic about their behavior. Everything happens for a reason and the list of reasons is small enough to manage." - Jim Bryan

"By this we mean that machine tool errors obey cause-and-effect relationships, and do not vary randomly for no reason. Further, the causes are not esoteric and uncontrollable, but can be explained in terms of familiar engineering principles." - Bob Donaldson

Professors Hiromu Nakazawa and Pat McKeown provide the following list of goals for precision engineering:
"
  1. Create a highly precise movement.
  2. Reduce the dispersion of the product's or part's function.
  3. Eliminate fitting and promote assembly, especially automatic assembly.
  4. Reduce the initial cost.
  5. Reduce the running cost.
  6. Extend the life span.
  7. Enable the design safety factor to be lowered.
  8. Improve interchangeability of components so that corresponding parts made by other factories or firms can be used in their place.
  9. Improve quality control through higher machine accuracy capabilities and hence reduce scrap, rework, and conventional inspection.
  10. Achieve a greater wear/fatigue life of components.
  11. Make functions independent of one another.
  12. Achieve greater miniaturization and packing densities.
  13. Achieve further advances in technology and the underlying sciences."

Technical Societies


See also

  • Abbe error
    Abbe error
    Abbe error, named after Ernst Abbe, also called sine error, describes the magnification of angular error over distance. For example, when one measures a point that is 1 meter away at 45 degrees, an angular error of 1 degree corresponds to a positional error of over 1.745 cm, equivalent to a...

  • Accuracy and precision
    Accuracy and precision
    In the fields of science, engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements of a quantity to that quantity's actual value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which...

  • Flexure bearing
    Flexure bearing
    A flexure bearing is a bearing which allows motion by bending a load element.A typical flexure bearing is just one part, joining two other parts. For example, a hinge may be made by attaching a long strip of a flexible element to a door and to the door frame...

  • Kinematic coupling
    Kinematic coupling
    Kinematic coupling describes fixtures designed to exactly kinematically constrain the part in question. A canonical example of a kinematic coupling consists of three radial v-groves in one part that mate with three hemispheres in another, credited to Maxwell...

  • Measurement uncertainty
    Measurement uncertainty
    In metrology, measurement uncertainty is a non-negative parameter characterizing the dispersion of the values attributed to a measured quantity. The uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity. All measurements are subject to uncertainty and a measured...

  • Kinematic determinacy
    Kinematic determinacy
    Kinematic determinacy is a term used in structural mechanics to describe a structure where material compatibility conditions alone can be used to calculate deflections....


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