Papers by Keyword: CAM

Abstract: In this work, the optimization problem is studied for a planar cam which rotates around its axis and moves a centered translating roller follower. The proposed optimization method is a genetic algorithm. The paper deals with different design problems: the minimization of the pressure angle, the maximization of the radius of curvature and the minimization of the contact pressure. Different types of motion laws are tested to found the most suitable for the computational optimization process.

Abstract: Shaking table is an important component in rapid detection system of microorganisms. Based on the discussion regarding the advantage and shortage of the shaking table, this paper proposed a simple, reliable, and low-cost automatic shaking table. Three mechanisms were discussed with the achievement of reciprocating motion: slide-crank mechanism, follower-cam mechanism, and incomplete gear mechanism. The three mechanisms were compared in mechanical motion pair, motion form, component design, and manufacturing process. The slide-crank mechanism was finally determined. To overcome the strong oscillation of the liquid in the test tube along a single direction, this paper improved the slider-crank mechanism, and whose trajectory was modified into an irregular circle.

Abstract: Due to their dimensions the micro-robots generally have a mono-mobile mechanical structure. This includes mechanisms acted by a single motor and consequently one input and multiple outputs. Such micro-robots have a fixed displacement strategy. The paper deals with the structural and kinematic characteristics of a robot complex mechanism with gears, cam and bars applied in different purposes [2, 3, 4, 5]. The systems may be equipped with various types of sensors such as tactile, proximity, sound and light ones.

Abstract: Throughout the production process, improper planning and exploitation of the CAD/CAM system leads to the low level utilization of the CNC milling machine. In product design, tangible prototype is fabricated using CAD/CAM techniques in the design phase to analyse and modify the product before actual production. In this research, industrial clay is used as the prototype material. The objectives of the study are to investigate the machining parameters of industrial clay using the CNC milling machine and to apply the CAD/CAM system in producing a clay sample part via the CNC milling machine. Using uncomplicated and low cost setup for the fabrication method, an industrial clay sample part is prepared in the CAD/CAM system and shaped using the CNC milling machine. The difference between the simulated and the actual machining time of the machined part is analysed.

Abstract: Based on the current design of actuator for soft-close automatic car doors, function and composition of the mechanical assembly and the electronic control module of the actuator are elaborated firstly. Then the push travel section of cam profile is optimized from previous circular arcs to a spline curve to reduce impact and fatigue wear between the switch and the cam in the mechanical assembly through multi-body dynamics simulation with the Adams solving tool in NX7.5. Besides, an improvement of the MOSFET bridge drive circuit and corresponding program design through dead-time control method with half-bridge chopper are applied to solve the heating problem in the electronic control module, in the light of equivalent electronic circuit simulation in Multisim. The results demonstrate that the optimization works well, and valuable conclusions can be drawn from system simulation during the prototype stage of the actuator product is practicable.

Abstract: This paper presents an attempt to apply wire cutting EDM for manufacturing of form tool edges with cemented carbide. Was made the experiment of comparing edges made using wire cutting EDM techniques and conventional made in the grinding process. As a result of edge life research were found to be reduced of life wire cutting EDM edge by 50% compared to the conventional edge. Pointed to the possibility of creating a CAD-CAM system for form tools, the application of which will accelerate the production of these tools.

Abstract: High cost is the major reason that there is not more wide-spread use of titanium alloys. Powder Metallurgy (P/M) represents one cost effective approach to fabrication of titanium components and Additive Manufacturing (AM) is an emerging attractive PM Technique . In this paper AM is discussed with the emphasis on the “work horse” titanium alloy Ti-6Al-4V. The various approaches to AM are presented and discussed, followed by some examples of components produced by AM. The microstructures and mechanical properties of Ti-6Al-4V produced by AM are listed and shown to compare very well with cast and wrought product. Finally, the economic advantages to be gained using the AM technique compared to conventionally processed material are presented. Key words: Additive Manufacturing (AM), 3D Printing, CAD, CAM, Laser, Electron beam, near net shape, remanufacturing, Powder Bed Fusion (PBF), Direct Energy Deposition (DED)

Abstract: Element geometry can be restored with basic measurement techniques. However if the element geometry is too complex (free form surfaces), it is not possible to take all measurements in that way. Example presented in the paper is a drop forged element (car suspension link). In situation when spare element is out of reach (product withdraw from market, producer technological process tooling redesign), the element can be reproduced (singularly or in series, what depends on producer). Reconstructed element is slightly different from a master element (impossible existence of reliably identically designed and manufactured parts), because of measurement uncertainty. Another problem is that original element is usually worn out or during disassembly process can be damaged, so it has different geometry,(when worn out is not fitting to tolerances) than newly manufactured one. The practical approach for reverse engineering is based on: measurement uncertainty extrapolation, 3D part scanning, transformation of point cloud to solid model, composition examination of an alloy. The method is a complex solution that brings: geometrical description and material assignment and heat treatment. Important part of the method is typical measurement techniques. In cases when tolerances have to be preserved, additional tolerance assignment is needed according to linkage between redesigned part of element and parts of other elements in assembly. The insurance of measurement was checked according to typical tolerance of the drop forged element. The retrieved 3D model was compared with virtual mass to real master element mass. The technological tooling reconstructed prototype and element reconstructed prototype have been made. Finally the alloy material is assigned according to measurement result analysis (electron spectroscopy EDS). Proposed example shows many important clues that can be used in order to provide properly redesigned element.

Abstract: The Material Loss Detection Method for Cylindrical Shape parts (MLDMCS) was presented in the previous article. The verification of the method was executed on two different samples, manufactured from different materials and with different geometries. The main goal of research was to set the diameter tolerance for a detection process. The first sample was examined nine times with a modification of one parameter diameter tolerance. The results interpretation gives a possibility to check the proper set of data for future cylindrical shape examinations according to accuracy class of manufacturing. Preparation of the first sample was done in order to check: centricity of compared models, uniform material los detection mechanical friction worn, various distribution and shape of material loss, various depth of material loss. Second sample was prepared in order to check correct detection of material loss in case when element have a feature (like key slot), that is in a part but simultaneously it exist according to design. The main target is to recognize with the algorithm: what is, what is not and properly classify material loss. Furthermore second examination sample was damaged in a border area of the mentioned feature. The presented verification proves that is possible to apply the proposed MLDMCS in industry to support overhaul process of technical means. The important part of examination preparation is a set of a technological base that is used to fit together sample model (from 3D scanning) and the design pattern model (from CAD design). The main result is a material loss digital presentation, 3D and 2D simplified distribution. Groups of material loss can be assigned to specific areas in order to prepare refurbishing process turning surface layer before laser cladding is applied. The distribution map (2D and 3D) fully corresponds to material loss distribution on samples. Time of element examination with MLDMCS is strictly related to accuracy in angle division and axial division in distribution of singular volume. The verification proves that the 3^rd generation of refurbishing process operation preparation is possible to put in to practice. However it has to be prepared with proper methods and equipment. The method should be applied especially in situation when an element is: refurbished in series, elements that are refurbished have similar design, elements characterizes with same accuracy class of manufacturing and similar diameters, but with various designs.

Abstract: In order to prepare a refurbishing process of an element that characterize with a material loss which is a result of worn process or damage could be 3D scanned. Then it 3D model is gained after triangularization process and surface fitting. This model is compared with a CAD model which is an element design representation. In order to provide such comparison, the proper implementation of the MLDMCS (Material Loss Detection Method for Cylindrical Shape parts) in to the software is needed. The software is prepared in Visual Studio environment (.NET) with C# programing language (the algorithm code and the interface), SQL server (database) and Siemens NX software (PARASOLID internal libraries). MLDMCS is implemented as the one of the author Computer Aided Overhaul software modules (CAO). The implementation is a complex task, according to: interface preparation, data collecting, data presentation an input data form, proper set of input data configuration, preparation of 3D graphics processing an analysis algorithms, preparation of output data form and interpretation. The result of software algorithm should be an easy to interpret set of data with a possibility of automatic rapport generation. Furthermore the data should be collected in a data base for future analysis of element worn and damage repeatable progression. Data collected each time from a element during it technical state examination gives also an answer to future proceeding according critical quantity of refurbishing processes in recirculation of technical mean. Additionally collected data gives suggestion of it repeatability in worn or damage after various technologies of refurbishing. Future systems probably will be set on such solution and MLDMCS will be one of typical method used in industry oriented to overhaul of machines parts. Previously presented article, shows only pure method with it foundations. Nowadays solutions are mainly based on a metrology, also supported with CMM (Coordinate Measuring Machines) and offline measuring paths generating systems. The accuracy of proposed solution (3D scanning and transformation of point clouds to solid model) is less accurate than typical measuring methods; however foresights of application are promising. The demand accuracy is sufficient in order to prepare a cladding process by turning worn-out or damaged surface layer.