UNIVERSAL MEASURING MACHINE-PPT
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This document discusses the Universal Measuring Machine (UMM) and its advantages over a Coordinate Measuring Machine (CMM). The UMM can inspect geometric features of parts more accurately than a CMM and can resolve the exact nature of errors in complex parts. Key components of the UMM include its ability to measure length, geometry, divide circles, and roundness. Attaining mechanical accuracy with the UMM requires mastery of these four areas. The document also provides details on inspecting parts, achieving mechanical accuracy, and the standards for length, dividing circles, and measuring roundness.
UNIVERSAL MEASURING MACHINE-PPT
- 2. ESSENTIAL COMPONENTS Length Geometry Division of circle Roundness
- 5. Comparison of CMM & UMM CMM UMM It is useful for rapid inspection of production parts. It does not inspect that much fast. It does not inspect Geometric features of the part. But UMM does it. It is not accurate. It is more accurate than CMM. Reveals the failure but not reason. UMM useful in this regard. It is useful for Quality control. It is capable of resolving the exact nature of the error of all part features, regardless of complexity.
- 6. INSPECTION ON UMM Essential that the work piece should be mounted carefully on UMM. Measuring the location of hole. Measuring of awkward shaped work pieces. Use of Microscopes for measuring small size holes.
- 7. MECHANICAL ACCURACY Attainment of “cubic concept” of accuracy in the UMM requires the individual mastery of four mechanical arts- Geometry, Length, Dividing of Circles and Roundness. These are truly the “Foundations of Mechanical Accuracy”.
- 8. Geometry Flat plane. Meehante cast iron(close grained). Elastic deformation-minimised-design and support. Temperature differentials affects the accuracy. Localized heating and cooling causes unpredictable distortion.
- 9. Standards of Length Internationally acceptable standards. Accuracy of derived length-standards such as gauge blocks, precision scales, step gauges, lead screws, and laser interferometer depends in large measure on how truthfully they represent the ultimate length standard.
- 10. Dividing the Circle Authority of “angles” of angle gauges, rotary tables, or the angular relationships in mechanical parts and assemblies is derived from the self-proving principle of dividing the circle
- 11. Roundness Precision machine tools must achieve roundness and especially with their spindles. Location, effective size and fit between mating parts are all dependent on the ability to measure and define the conditions of roundness.