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AMP 2018 02 15 Ex2 120 blind holes have to be drilled on a carbon steel plate using plunge EDM. As a final task, you have to select the best ton. You can derive some useful information from Figure 1 and Table 1. Figure 1 1. Calculate the total volume to be removed from the plate, the length and the actually usable volume of each tool. Assumption: the clearance between the tool holder and the plate upper surface is equal to the gap between the tool tip and the machined surface. vholes [mm3] lu1tool [mm] vu1tool [mm3] Table 1 FEATURE, TOOL AND PROCESS DETAILS Symbol Value Unit FEATURE Hole diameter dhole 2 mm Hole depth (blind) lhole 12 mm TOOL Tool diameter dtool 1.95 mm Tool length (out of tool holder) ltool 40 mm MACHINING PARAMETERS Maximum ton allowed ton_max 40 µs Change & setup time (single tool) change time 2.5 min 2. Select the two preferable configurations looking at Figure 1, in order to enhance the productivity, maximising and minimising the MRR of plate and/or tool. Config 1 Config 2 ton [µs] MRRpiece [mm3/min] MRRtool [mm3/min] 3. Calculate the most significant productivity indicators. The tool Change & setup time must be charged for each tool that you use (even partially). Other times are negligible. Config 1 Config 2 Material removal time [min] Tool life [min] Number of tools [tools/batch] Change & setup time [min/batch] Operation time [min/batch] Configuration choice (put a ✓) 4. Your workshop is ready to build a “quick change” device for the tool: calculate the trade-off Change & setup time that makes the two configurations equivalent. Single tool change & setup time _ trade off: …………………… [min] SOLUTION 1. Calculate the total volume to be removed from the plate, the length and the actually usable volume of each tool. Assumption: the clearance between…