The diploma thesis contains detailed processing of a two-piece car form by means of possible accessible 3D strategies of CAM system PowerMILL, selecting of tools, economical evaluation and creation of NC program for CNC machining centre.

The aim of this dissertation are future trends of electrical discharge machining in conditions of a small tool factory. In the introduction is presented the theory of non-conventional machining. The practical part is focused on valuation the current level of electrical discharge machining, the importance of the use in a tool Nástrojárna Ryšavý. It also compares the level of leading global manufacturers of electrical discharge machines and future trends of electro-discharge technology.

The theoretical part of this thesis is introducing basic information in production of shaped components on CNC machines. It describes each steps from a design of the component to production. Main target is summarization of available modern technologies that can be used. Experimental part uses these modern technologies for processing design shaped component. It describes process of design 3D model part in CAD system, subsequently creation of program for machining in CAM system and solves production of part on CNC machine. The aim of this thesis is design part with interesting design and production difficult enough to represent company, where it was made.

Thesis contains summarizing of main activities of technological projecting. The project itself analyzes the production of gear-boxes on a machine line, which caused transferring the production to a machining center. This real project is implemented on the basis of very detailed cost calculations substantiated by a positive result.

This thesis investigates end-effector systems used in a chemomechanical scribing process. Chemomechanical scribing is a method of patterning silicon to selectively deposit a monolayer of material on the surface of the silicon. This thesis details the development of a unique end-effector for chemomechanical scribing using a compliant mechanism solution. The end-effector is developed to scribe lines that have uniform geometry and produce less chipping on the surface of the silicon. The resulting scribing mechanism is passively controlled, has high lateral stiffness, and low axial stiffness. The mechanism is analyzed using the pseudo-rigid-body model and linear-elastic beam method to determine the axial stiffness, finite element methods to determine the lateral stiffness, and fatigue analysis to determine mechanism cycle life. This thesis also investigates the significance of mechanical factors on the chemomechanical scribing process using the compliant end-effector. The factors examined are scribing force, scribing speed, tip geometry, wafer orientation, and wetting liquid. The factors are analyzed using a two-step approach: first, an analysis of the influence of the mechanical factors on line characteristics and second, an analysis of the influence of line characteristics on line performance.

As competition grows among manufacturing companies, greater emphasis has recently been placed on product aesthetics and decreasing the product development time. This is promoting and standardizing widespread use of sculptured surface styling within product design. Therefore, industries are looking for high efficiency machining strategies for sculptured surface machining (SSM). Many researchers have produced various methods in tool path generation for SSM. Five-axis curvature matched machining (CM2) is the most efficient. With the widespread use of 5-axis mill in industries, CM2 is a better solution for improving the machining efficiency for product concept models. CM2 has very good performance for global machining of single patch surface or a quilt of simple sculptured surface patches. But when CM2 is used to generate tool paths for global machining of a large region of complex sculptured surface such as the top or side skins of a vehicle, there will be some limitations, that is, the performance will be influenced greatly in some steep areas where the lead angle of the tool becomes larger to match the curvature or avoid gouging. Larger lead angles mean smaller effective curvatures at the leading edge of the tool bottom where it contacts the part surfaces. Therefore, the density of CM2 tool path is very high in these steep regions. By setting a smaller upper limit for the lead angle, the density of tool path will not be very high in the steep regions, but there will be some uncut materials. This thesis focuses on how to determine the uncut or rework areas of the previous CM2 and how to define the boundary of these regions. Strategies for generating more efficiency CM2 tool paths are also discussed. These methods will be tested by applying finish global machining to a one-fourth scale Ford GT model.

Wire electrical discharge machining (WEDM) is a precision machining process that uses electrical discharges struck between an axially moving wire electrode and the workpiece to remove material through melting and vaporization. WEDM is replacing traditional processes like broaching for machining safety-critical components such as the turbine disk in the manufacture of fuel-efficient jet engines. The main issue preventing the more widespread use of WEDM is that due to WEDM being less productive than broaching, it currently requires 6 WEDM machine tools to replace a single broaching machine to maintain the same throughput. The main factor limiting WEDM productivity is wire breakage. To increase the Cutting Rate (CR) more power is required, and increasing power also increases the likelihood of breakage. The goal of this research is to determine whether wires thicker than the conventional 0.25 mm diameter will both optimize the cutting rate and minimize breakage. Thicker wires will allow for an increase in the duty factor, with a significantly decreased incidence of wire breakage. Given that an increased wire diameter also increases the kerf width, this research seeks to identify the optimal wire diameter that maximizes the linear cutting rate. This research concluded that using wire of optimal diameter in WEDM increases the CR by as much as 400%. / Thesis / Master of Science in Mechanical Engineering (MSME) / In order to secure jet engine blades onto the engine, complex features called Firtree Root Forms (FTRF) are used. These features need to be very precisely cut in order for the engine to work at peak efficiency. Currently, industry is using a manufacturing process called broaching to machine these FTRFs, however broaches wear out over time, which causes imprecise cuts. The solution to this is to use Wire Electrical Discharge Machining (WEDM). The problem with WEDM is that it takes on average 6 machines to replace a single broaching machine in terms of productivity. The objective of this project is to increase the cutting speed (and thus productivity) of WEDM, and one of the ways to do that is to increase the electrode wire diameter. This allows for more power to be used in the machining process without the risk of wire breakage, which is a major problem when cutting with WEDM. The research presented in this thesis successfully demonstrates that using thicker wires in WEDM can cut as much as 400% faster than the wires currently in common use in industry.

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<p>Electrical discharge machining (EDM) is a non-conventional machining process utilizing a series of electrical discharges to melt and vaporize workpiece material. In a wire EDM configuration wire breakage is a limiting factor in the machining productivity during the machining of workpieces with varying heights. Present methods of estimating workpiece height on-line in an effort to optimize machining parameters monitor the electrical signals for changes which may not be completely indicative of a change in workpiece height. This thesis intends to utilize acoustic emission (AE) sensors as a method for mapping the discharge location in order to estimate the workpiece height. This represents a novel approach as acoustic emission testing, while prevalent in the process monitoring of numerous conventional machining processes has yet to be significantly studied in combination with EDM.</p> <p>Another useful application of AE sensors with the EDM process under consideration is during the fast hole EDM process, where excessive wear is seen in the electrode causing true electrode length to remain uncertain. By using acoustic emission sensors to determine the true length of the electrode it could be possible to aid in the breakout detection of the electrode.</p> / Master of Applied Science (MASc)