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Accuracy and Error Compensation of CNC Machining Systems
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
Generally, every machine tool builder lists, as part of a machine’s specification, accuracy, and repeatability figures. However, the method or standard utilized to measure these figures is not provided, which makes very difficult for users to compare machine tools or decide the part quality expectations. The most important steps to take for obtaining CNC machine position accuracy are as follows: Request positional accuracy from the manufacturer for each CNC axis. This involves a request for values according to ISO 230-2:2006. If VDI/DGQ Standard is used, request for positional uncertainty values. The values should be measured bidirectionally and should be reported as the total absolute amount (not as ± value).Review product brochures or technical specification literature for reported position accuracy and note the standard used.Review runoff documentation and note values for position accuracy that were demonstrated and the procedure followed for the evaluation.Review current or recent past part machining capability information to estimate the positional accuracy based on six-sigma calculation of feature dimensional capability.
Multi-period additive/subtractive product platform design and inventory management
Published in International Journal of Production Research, 2022
Mostafa Moussa, Hoda ElMaraghy
Additive manufacturing offers substantial improvement and faster processing time of printed parts with good quality and a range of dimensions and materials such as plastics, cement, and metals (Kumar, Pandey, and Wimpenny 2019; Tofail et al. 2018; Tareq et al. 2021). However, additive manufacturing is relatively expensive, and the processing time per part is longer than subtractive manufacturing. Therefore, traditional subtractive manufacturing remains essential and cannot be entirely replaced by additive manufacturing. Combining the capabilities of technologies comes into play across many application areas (Dilberoglu et al. 2021; Moussa and ElMaraghy 2020). Among these application, areas are using an additive process to build a near-net shape of a part with complex geometry that will then be machined to its final shape obtaining the desired accuracy such as Zhang, Soshi, and Yamazaki (2020). In addition, some researchers utilised the combination of additive and subtractive manufacturing for remanufacturing legacy products by adding or removing features (Zhu, Dhokia, and Newman 2017). Okuma, a CNC (Computer Numerical Control) machine tool builder and RPM innovations, a metal additive manufacturing machine maker, presented an industrial example of a manufacturing cell that utilises additive and subtractive manufacturing for customisation. This manufacturing cell produced combustor cases. The cost analysis of this cell showed the feasibility of customisation using additive and subtractive manufacturing to produce combustor cases with less time and cost and higher productivity (Zelinski 2016).
A review of energy consumption and minimisation strategies of machine tools in manufacturing process
Published in International Journal of Sustainable Engineering, 2021
Lukman Aminu Yusuf, Kayode Popoola, Haruna Musa
There has been substantial research undertaken on energy minimisation strategies from different perspectives such as machine tool builder, manufacturing industrial processes, management and government policies, energy audits (Abdelaziz, Saidur, and Mekhilef 2011); May et al. 2017). In this paper, we shall examine the review of energy consumption by machine tools and energy minimisation strategies in the manufacturing process. The aim is to review the existing state-of-the-art methods using a top-to-bottom approach and to highlight possible future approaches for minimising energy consumption in the manufacturing industry.