CAD/CAM

By:- Krunal Shah

TOPIC:- COMPUTER-AIDED PART PROGRAMMING, GEOMETRY STATEMENT , POST PROSSESOR STATEMENT & EXAMPLE OF APT PART PROGRAMMING

COMPUTER-AIDED PART PROGRAMMING,

GEOMETRY STATEMENT , POST PROSSESOR

STATEMENT & EXAMPLE OF APT PART

PROGRAMMING.

COMPUTER-AIDED PART PROGRAMMING:-

Part programming method discussed so far are suitable for relatively simple parts involving a small number of features. However, for very complex shaped involving three dimensional motion, preparing a part program purely by manual means may mean a lot of calculation and the associated time spent in developing the program. All this may lead to inaccuracies and complications within the program. Computer aided part programming method are therefore used for complex shaped that are difficult or impossible to be programmed using manual methods.

GEOMETRICAL STATEMENT:-

These are many ways in which the part geometry in APT could specify. The part geometry is normally broken into a number of surface elements that could be defined from the data given in a part point. These are POINT, LINE, CIRCLE, PLANE, VECTOR, PATERN, SPHERE, GCONIC, TABCYL, etc. For each of the types of surface that can be defined, a number of alternative ways are possible for definition to simplify the definition procedure. For each of the definitions, the general form is presented in which the following rules definition procedure. For each of the definition, the general form is presented in which the following rules are observed:

i. A symbol in lower case letters underline represents the surface type

specified. ii. A symbol in lower case letter without under line represents a

scalar. iii. The word shown in the upper case letters are the MINOR keyword. iv. All possible modifiers are one below the other enc losed by an

opening brace from among which only one appropriate for the definition is to be selected.

POSTPROCESSOR STATEMENT:-

These commands are used to specify the machine tool functions and are supposed to be acted upon by the post processor identified earline in the part program.

This specifies the type of cutting fluid application to be used & when to start and stop.

EXAMPLE OF APT PART PROGRAMMING:-