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Planning for CNC

Operations

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Coordination of 5 functions

1. NC management - shop supervisor

2. Part programming - programmer

3. Machine operators

4. Tool and fixture preparation - tool

room person

5. Machine and controller

maintenance

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Process planning - detailed

operation planperson often called a process

planner

links engineering design with shopfloor machining

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Planning considerations (6)

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1. Raw material

considerationssize and shape

amount of material to be removed

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2. Datum Selection

reference surfaces for machining and

mating parts

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3. Process capability

holding tolerances

surface finish quality

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4. Process selection and

sequencing (p129)

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5. Tool path planning

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6. Machining parameters

speeds, feeds, depth of cut

depth of cut determined by available

spindle horsepower and rigidity ofcutter and machine

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NC documentation (6)

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1. Raw material drawings

specs on material type

shape and dimensions of the blank

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2. Production drawings

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3. Operation sheet

required processes

sequences

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4. Tooling plan

list of tools (p157)

offsets (p160)

presets

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5. Workholding and

machine setup sheet locating positions

clamping positions

clamping methods

list of locating and clamping devices

special notes - clamping forces,pressures

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6. Programming sheet