Browsing by Author "Nagel, M"

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    Development of an Abbe error minimization concept for coordinate measurement machines.
    (Stellenbosch : Stellenbosch University, 2024-02) Nagel, M; Schreve, K.; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.
    ENGLISH ABSTRACT: Coordinate metrology is an expensive field and the benefit to be gained by making it available to a larger part of the engineering industry should be substantial. Coordinate measurement machines (CMMs) form a large cost point in this field as they are specialised pieces of equipment that require well-trained personnel to operate, and controlled environments to achieve high accuracy. A large hurdle to low-cost CMM design is the accuracy required to manufacture them to avoid errors. Abbe error is one of these inaccuracies, also known as cosine error, and it can be described as a misalignment of the measurement axis and the scale used to take a distance measurement. The CMM concept developed in this project shows the potential of such a system to be further developed into a viable tool. This was achieved through the development of a spherical parallel mechanism which has primarily been used as a manipulator. This mechanism has been used as part of the measurement system to minimize the Abbe error in the first system prototype. A kinematic error model was created to aid in the development of the physical concept. A series of physical tests were carried out and compared to simulated results from the error model. This comparison was used to validate the understanding of the system and the prevalent error sources. The preliminary design and construction of the CMM have been shown to outperform the manufacturing and assembly processes used by achieving confident levels of accuracy. The parallel mechanism greatly decreases the effect of individual component errors. In conclusion, the system shows a promising future for new coordinate measurement machines by using non-conventional means to minimize error.