An important aspect of DFM is to anticipate the possible failure modes of the production system and to take appropriate corrective actions early in the development process. This strategy is known as error proofing. One type of failure mode arises from having slightly different parts thah can be easily confused. Examples of slightly different parts are screws differing only in the pitch of the threads (e.g., 4 x .70 mm and 4 x .75 mm screws) or in the direction of turning (left - and right - handed threads), parts which are mirror images of each other, and parts differing only in the material composition.
(Kalpakjian S. , Schmid S.R. , Manufacturing Engineering and Technology, p. 227)
Prototyping
Although dictionaries define prototype as a noun only, in product development practice the word is used as a noun, a verb, and an adjective.
We define prototype as "an approximation of the product along one or more dimensions of interest." Under this definition, any entity exhibiting at least one aspect of the product that is of interest to the development team can be viewed as a prototype.This definition deviates from standard usage in that it includes such diverse forms of prototypes as concept sketches, mathematical models, simulations, test components, and fully functional preproduction versions of the product. Prototyping is the process of developing such an approximation of the product.
(Kalpakjian S. , Schmid S.R. , Manufacturing Engineering and Technology, p. 247)
Free - Form Fabrication
In 1984, the first commercial free - form fabrication system was introduced by 3D Systems. This technology, called stereolithography, and dozens of competing technologies which followed it, create physical objects directly from 3D CAD models, and can be thought of as "three - dimensional printing." This collection of technologies is offen called rapid prototyping. Most of technologies work by constructing an object, one cross - sectional layer at a time, by depositing a material or by using a laser to selectively solidify a liquid or powder. The resulting parts are most offen made from plastics, but other materials are avaliable, including wax, paper, ceramics and metals. In some cases the parts are used directy for visulation or in working prototypes. However, the parts are offen used as a patterns to make molds or patterns from which parts with particular material properties can then be molded or cast.
Free - form fabrication technologies enable realistic 3D prototypes to be created earier and less expensively than was possible before.
(Kalpakjian S. , Schmid S.R. , Manufacturing Engineering and Technology, p. 258)
Tactile Sensing
Tactile sensing is the continuous sensing of variable contact forces, commonly by an array of sensors. Such a system is capable of performing within an arbitrary three - dimensional space. Fragile parts (such as glass bottles and electronic devices) can be handled by robots with compliant (smart) end effectors. These effectors can sense the force applied to the object being handled using piezoelectric devices, strain gages, magnetic induction, ultrasonics, and optical systems of fyber optics and light - emitting diodes.
(Kalpakjian S. , Schmid S.R. , Manufacturing Engineering and Technology, p. 1173)
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