Sustainability Modeling Approach on Remanufacturing Conventional Lathe into CNC Machine Tool

Aims: Sustainability modeling to study possibility of proposing several remanufacturing alternatives of conventional lathe into CNC machine tool.

Study Design: Conventional machine tool into CNC machine remanufacturing-upgrading experience is mixed with literature based analysis to weight the criteria and the alternatives of assessment. Global weights are found to rank the alternatives. Suitable literature can be projected comparatively to construct sustainability model. Sustainability assessment models in field of lathe remanufacturing-upgrading are reviewed and modified to accommodate new changes that accompany the current case study.

Place and Duration of Study: Middle Technical University, Institute of Technology-Baghdad, Mechanical Techniques Department, between 2019 and 2020.

Methodology: 1- Literature survey to find out the most used sustainability assessment criteria.

2-Economic, environmental and social criteria specifying.

3-Normilizing weights of criteria.

4- Matching local weights of assessment criteria with fuzzy triangular numbers to find out the whole weights.

5-Senairo based analysis application to find out alternatives of remanufacturing.

6-Weighting alternatives, criteria and sub-criteria.

7- Find global weights and rank the alternatives.

Decision making for selection of remanufactured alternatives and remanufacturing alternatives can include :(1) Spindle , gearbox and dovetail guide ways reuse scenario. (2) Spindle remanufacturing scenario. (3) Gearbox remanufacturing scenario. (4) Dovetail guide ways remanufacturing scenario.(5) Spindle and gearbox remanufacturing scenario. (6) Spindle and dovetail guide ways remanufacturing scenario. (7) Spindle, gearbox and dovetail guide ways remanufacturing scenario. Alternatives in field of machine tools remanufacturing are reviewed. Experience in field of machine tool remanufacturing is exploited to remodeling the existence models to optimize a remanufactured lathe into CNC machine case study.

Results: Emerging technology aided Conventional-CNC lathe remanufacturing-upgrading alternative exhibits good behavior of criteria toward optimization. While advanced technology aided Conventional-CNC lathe remanufacturing exhibits behavior to be of interesting developing potentials. Conventional-Conventional lathe remanufacturing is of lower potentials to be developed into optimum solution.

Conclusion: Remanufacturing-upgrading of conventional lathe into CNC machine in its mechanical part, it is merely traditional remanufacturing process of conventional lathe where gearbox can be eliminated due to use of motorized axis. Feed rod and lead screws, in both forward and transvers directions, can be replaced with motorized ball screws. Also tool post can be replaced with automatic tool changer while saddle can be reused. The most promising technological key is the use of mate/insert/screw to assembly ball guide ways to disable dovetail guide ways and highlight structural specifications of CNC lathe. Thus precision, accuracy, repeatability and reliability will be enhanced considerably. Comparative literature based analysis and experience based analysis with uncertainty reduction can substitute the leak of relevant data acquisition for remanufacturing-upgrading modeling. Which enables simplify certain difficulties and the calculations of some criteria and adopts simplified methods so that theoretic and practical gap can be directed towards certain actual conditions to reach the optimum solution.