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This paper aims to investigate the performance and positioning accuracy of computer numerical controlled (CNC) feed drive system using a ball screw-based pre-loading impact factor.

Initially, axial displacement of support bearings has been computed in relation to the different preload values. Among the computed values, a basic rule equation has been developed for the calculation of elongation in the bearings. The value of displacements computed from the developed equation has been considered as a pre-loading value, and its behavior on the feed drive system has been analyzed.

The elongation of bearings impacts the positioning accuracy and repeatability of the feed drive system and of CNC machines. Next, an analytical model for the rigorous assessment of CNC feed drive system has been designed and developed. The positioning accuracy of CNC machine in relation with different pre-loading values has been analyzed.

The results obtained from these investigations enhance the positioning accuracy of CNC machining centers. The optimum pre-loading value has been analyzed among the available ranges, and it has been proposed that optimal results have been achieved at 5 per cent of dynamic load rating.

This paper proposes improved explorations toward the performance of the CNC machines by optimizing the positioning accuracy through pre-loading. Finally, analytical estimations have been carried out to prove the validity of the proposal.

This paper aims to propose an elementary approach towards the measurement of a globoidal cam profile used in an automatic tool changer (ATC) of computer numerical control (CNC) machines.

A simple and unique online method has been designed for the profile metrology of the cam. This simple methodology will replace the traditional methodology of profile metrology of cam by coordinate measuring machine (CMM). A globoidal cam with an indexable turret and roller follower (rotating in an enclosed track) has been evaluated in our analysis. This analysis plays a significant role in the performance determination of the cam as well as the ATC of CNC machines.

A novel model has been designed and implemented to investigate the profile of a globoidal cam. The proposed methodology becomes an enhancement over the old methodology, i.e. measurement through CMM. Theoretical analysis and practical implementation prove the significance of the method.

An enhanced methodology to effectively measure the globoidal cam profile has been proposed. The practical implication of the proposed methodology remains for the CNC machine tool and ATC manufacturers. Finally, analytical explorations have been carried out to prove the validity of the proposal.

Ankle–foot orthoses (AFOs) are assistive devices prescribed for a number of physical and neurological disorders affecting the mobility of the lower limbs. Additive manufacturing has been explored as an alternative process; however, it has proved to be inefficient cost-wise. This work aims to explore the possibilities of generating modular AFO elements, namely, calf, shank and footplate, with the localized composite reinforcement that aids in the optimization of the device in terms of functionality, aesthetics, rigidity and cost.

The conventional lower leg–foot orthosis configuration depends on thermoforming a polymer sheet around a mortar cast with a trademark firmness relying upon the trim-line with the inalienable plan restrictions. In manufacturing of AFO the expert, i.e. orthotist's, guidance is used. Polypropylene and polyethylene material is used in fabrication of AFO to complete all-round reported points of interest over the ordinary outlines, yet their mechanical conduct under administration conditions cannot be effectively anticipated.

AFOs made of polypropylene and polyethylene material are available in the market, which are used by children of age 3-5 years. With the existing AFO design, patients are facing excessive heating and sweating problems during long-term usage. After feedback from patients and orthotists (who prescribed AFO to patients), an attempt has been made to solve the problem with a new and improved AFO design of AFO by using finite element modelling and stress analysis. Also, the results indicate that the new design is similar to the actual product design.

This work introduces the low-cost 3D printing with reinforcement approach as an alternative route for the designing and manufacturing of orthotic devices with complex shapes. It is expected that new applications add-up to increase the body of knowledge about the behaviour of such products which will mix both areas, composite theory and additive manufacturing. This study investigated the fields related to 3D scanning, 3D printing and computer-aided designing for the manufacturing of a customized AFO.

The purpose of the study is to fabricate a joint between two aluminium metal matrix composites using microwave hybrid heating (MHH).

Taguchi design of experiments was applied to conduct the experimental study. The mechanical properties such as ultimate tensile strength, micro-hardness and porosity were studied. Grey Relational Analysis was applied to understand the significance of fabrication parameters of best performing sample. The dominant factor of fabrication was analysed using ANOVA. The best performance sample was further characterised using X-ray diffraction and field emission scanning electron microscopy. Energy dispersive X-ray was used to analyse the elemental composition of the sample.

The Aluminium Metal Matrix Composite (AMMC) joint was successfully fabricated using MHH. The mechanical properties were mainly influenced by the fabrication factor of exposure time.

The formation of AMMC joint using MHH might explore the way for the industries in the field of joining.

The purpose of this study is improvement of human gait by customized design of ankle foot orthosis (AFO). An has been the most frequently used orthosis in children with cerebral palsy. AFOs are designed to boost existing features or to avoid depression or traumatize muscle contractures. The advantages of AFO’s utilized for advancement in human walk attributes for the improvement in foot deformities patients or youngsters with spastic loss of motion. In this research on the customized design of AFO's to improve gait, there are limitations during walking of foot drop patients. In children with foot drops, specific AFOs were explicitly altered to improve parity and strength which are beneficial to walking positions.

This study proposes the customized design of AFOs using computerized and additive manufacturing for producing advances to alter the design and increase comfort for foot drop patients. Structuring the proposed design fabricated by using additive manufacturing and restricted material, the investigation was finalized at the Design Analysis Software (ANSYS). The system that performs best under investigation can additionally be printed using additive manufacturing.

The results show that the customized design of AFOs meets the patient’s requirements and could also be an alternative solution to the existing AFO design. The biomechanical consequences and mechanical properties of additive manufactured AFOs have been comparable to historically synthetic AFOs. While developing the novel AFO designs, the use of 3D printing has many benefits, including stiffness and weight optimization, to improve biomechanical function and comfort. To defeat the issues of foot drop patients, a customized AFO is used to improve the human gait cycle with new material and having better mechanical properties.

This research work focuses on the biomechanical impacts and mechanical properties of customized 3D-printed AFOs and compares them to traditionally made AFOs. Customized AFO design using 3D printing has numerous potential advantages, including new material with lightweight advancement, to improve biomechanical function and comfort. Normally, new applications mean an incremental collection of learning approximately the behavior of such gadgets and blending the new design, composite speculation and delivered substance production. The test results aim to overcome the new AFO structure issues and display the limited components and stress examination. The outcome of the research is the improved gait cycle of foot drop patients.

The purpose of this study is to find out the reasons why companies achieve different results in following different business excellence (BE) models. This has been done using a case study method, selecting to illustrate the actions taken and the results achieved by two role model companies, one following the Malcolm Baldrige model (MBM) and the other following the European Foundation for Quality Management (EFQM) model.

The research design adopted is as follows: examine the literature of Total Quality Management (TQM) and BE, with specific reference to practices and happenings in Indian industry, to identify the key themes; analyse the research questions RQ1and RQ2 as mentioned above, using the learnings from the literature survey in a qualitative way. The analysis is done using chronological developments in TQM, BE and linking them with the happenings in Indian industry in a cause–effect way; develop a “source to sink” framework to track the various actions implemented by companies to drive BE in their quest to performance excellence, and to analyse the root causes for the success of the actions; illustrate the conclusions through two case studies, of two different companies from India, on the varied results achieved from following two different BE models, one, the MBM by Tata Steel, and, two, the EFQM by BHEL, both award-winning companies, for instilling “excellence” in performance; and develop a model to correlate the observations from the companies using two constructs, identifying latent variables and actions that have been taken to address the outcomes of the variables.

The findings show that the actions taken by the companies are different, under the two models. The reasons for these different actions have been described, and the impact of these on the latent variables and outcomes have been tracked. There are six reasons why the results are different.

The study has highlighted the efforts by two role model companies. These are “comparisons of the best in the business” in their respective industries. However, one needs more studies to verify and establish whether the six reasons described are the ones which are most impactful. More companies need to be studied, and, based on the outcomes, one can establish the “best choice of the BE model” for Indian companies.

The results of the study show that using different BE models can affect the results. A non-optimal choice may lead to longer time and lower results.

Excellent companies are sustainable, which means that they eliminate waste, operate in an environmentally friendly manner and address social issues. Speedily achieving excellence can lead to faster use of sustainable operations.

The work is original in the following ways: data collection through assessment teams; experience through personal engagement; identifying six reasons and two constructs which could lead to different results.

The purpose of this paper is to apply a framework for value stream mapping (VSM) integrated with fuzzy quality function deployment (QFD) for enabling scientific prioritization of improvement proposals to improve leanness.

The literature was reviewed from the perspectives of VSM, QFD and fuzzy logic applications. The current state map was developed for the case component; fuzzy QFD was used for prioritizing improvement proposals and prioritized proposals were incorporated in the future state map.

The approach enabled the scientific mapping of wastes with improvement proposals and thereby enabling systematic implementation of improvement proposals. The conducted pilot study resulted in 4 percent reduction in cycle time. As the lean implementation is a continuous process, furthermore improvements are expected in near future.

The study was conducted in an Indian camshaft manufacturing organization. The improvements in terms of leanness parameters were quantified.

The findings determined from the study has practical relevance. Besides, managerial implications were also discussed.

The study presented in this paper was conducted in a real time manufacturing environment. Hence the contributions of study are found to be valuable among academic and practicing communities.

It is difficult for anyone to implement all the lean tools simultaneously. One of the core issues is identifying critical criteria for the successful implementation of lean manufacturing (LM) and evaluating them. The purpose of this paper is to analyze the causal relationships of LM criteria in a machine tool manufacturing firm located in national capital region of India using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) method.

The research paper presents a blend of theoretical framework and practical applications. Based on literature review, 17 LM criteria were extracted that were validated by experts. A questionnaire was developed that was answered by experts serving in the XYZ machine tool manufacturing firm. Then, the DEMATEL method was applied to analyze the importance of criteria and the casual relations among the criteria were developed.

Using DEMATEL, the lean criteria were divided into cause group and effect group. In this study, information technology, computer-integrated manufacturing, enterprise resource planning, training, fixed position layout, smart processes and automation and concurrent engineering were classified in the cause group. Just in time, value stream mapping, 5-S, single minute exchange of die, visual control, job scheduling, standardized work, cellular manufacturing, poka-yoke, and total quality management were categorized in the effect group. The DEMATEL framework indicates that “training” is the most influencing factor for the lean implementation process in machine tool sector.

To know the key lean criteria and relationship among them can help many organizations to develop lean competencies. If the authors want to obtain high performance in terms of the effect group factors, it would be necessary to control and pay a great deal of attention to the cause group factors beforehand. This study is perhaps among the first few with focus on segmenting the set of lean criteria into some meaningful portions in order to effectively facilitate its implementation. The paper provides useful insights to the lean production implementers, consultants, and researchers.

The purpose of this paper is to provide a conceptual framework which connects theory with straightforward application of statistical process control (SPC) in discovering and analyzing causes of variation to eliminate quality problems, which not only helps small and medium enterprises (SMEs) to improve their processes but also helps to attain competitive positioning.

Based on theory and methodological framework, an experimental study has been presented. Use of histograms, X (bar) and R control charts and process capability plots and cause-and-effect diagrams have been made to analyse the assignable causes. A case from an SME engaged in machining of automotive parts is investigated.

The results demonstrate the effectiveness of SPC in evaluating and eliminating quality problems. The machine capability (C_P) and the process capability (C_Pk) values are also obtained to know inherent variation in the process. If these quality tools are applied with management support and apt knowledge, attained through proper training and motivation, then in this cut-throat competitive world, SMEs can establish their market position by enhancing the quality and productivity of their products/processes.

From the study, the authors conclude that application of SPC requires thorough preparation, management commitment and human resource management through proper training, teamwork and motivation embedded with a sound measurement and control system.

The present study bridges the gap between theory and practice by developing a conceptual framework and providing a practical support by illustrating a case from an SME engaged in machining of automotive parts.