Planning for CNC Operations Coordination of 5 functions

Planning for CNC Operations

Coordination of 5 functions u 1. NC management - shop supervisor u 2. Part programming - programmer u 3. Machine operators u 4. Tool and fixture preparation - tool room person u 5. Machine and controller maintenance

Process planning - detailed operation plan u person often called a process planner u links engineering design with shop floor machining

Planning considerations (6)

1. Raw material considerations u size and shape u amount of material to be removed

2. Datum Selection u reference surfaces for machining and mating parts

3. Process capability u holding tolerances u surface finish quality

4. Process selection and sequencing (p 129)

5. Tool path planning

6. Machining parameters u speeds, feeds, depth of cut u depth of cut determined by available spindle horsepower and rigidity of cutter and machine

NC documentation (6)

1. Raw material drawings u specs on material type u shape and dimensions of the blank

2. Production drawings

3. Operation sheet u required processes u sequences

4. Tooling plan u list of tools (p 157) u offsets (p 160) u presets

5. Workholding and machine setup sheet u locating positions u clamping methods u list of locating and clamping devices u special notes - clamping forces, pressures

6. Programming sheet