 | Centring, Drilling and Counterboring / Countersinking - Course: Techniques for Machining of Material. Instruction Examples for Practical Vocational Training |
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Instruction example 3.2.: Die plate
This example serves to practise centring with the turning tool on rotationally symmetrical parts held in a chuck
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Material
100 Cr 6 (100 = 1 % carbon; Cr 6 = 1.5 % chromium)
Dimensions
dia. 32×47
Cutting and operating tools
Inside turning tool for corner work, key
Measuring and testing tools
Vernier caliper, dial gauge, protractor
Accessories
Stepped chuck jaws which can be turned out, supporting plates, coolant, Vee (for round cross section of turning tool shaft)
Required previous knowledge
Reading of drawings, measuring and testing, scribing and prick-punching
Explanations to the working drawing
(0.04) = admissible true-running error of 0.04 mm not to be exceeded.
Surface finish: finished Rz 20
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Sequence of operations |
Remarks |
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1. Dimensional inspection | |
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2. Clamping of workpiece |
Type of clamping: "chucking" in stepped chuck jaws which can be turned out. Chuck on dia. 30, measure on dia. 20, maintain admissible deviation. Check for true running. If necessary, turn out chuck jaws. Interrupted cut! Wear safety goggles I |
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3. Clamping of tool |
Clamp short. See to necessary clearance angle. Swivel top slide by 30 degrees. |
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4. Setting of cutting values | |
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5. Tool to take first cut |
Set end stop. Let tool take first cut at interedge between end face and surface of hole by means of top slide adjustment. |
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6. Centring |
Adjust cross slide to the left. Manually finish-turn centre hole by top slide adjustment. Use coolant for tools without carbide tips. |
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7. Dimensional and surface inspection | |
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8. Unloading |
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Figure
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