Automatically programmed tool (ATP)

APT stands for Automatically Programmed Tool. It is a language that defines the tool path with respect to the part
geometry, and often forms the basis for post-processor generated NC files.

1. Automatically Programmed Tool (ATP) By MANOJ K 1MS16MCM09 MSRIT

2. ATP It is a language that defines the tool path with respect to the part geometry. Or It is a program which consists of instructions/statements which are used to specify the path of the tool to follow for producing a given part. Developed by MIT in 1959

3. TYPES OF STATEMENTS Geometry statements Motion statements Postprocessor statements (feed, speed, coolant, …etc) Auxiliary statements(tool, tolerance, part, … etc)

4. GEOMETRY STATEMENTS It defines a geometric shape/form. There are 16 different geometric forms e.g.-POINT, LINE, PLANE, CIRCLE, CYLNDR, ELLIPS,HYPERB, CONE, PATERN,….etc The general form of geometry statements is: symbol = geometry type / descriptive data

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6. MOTION STATEMENTS Used to define the tool movement in a specific direction. In APT there are two basic types of motion statements: Point to Point motion (PTP) Contouring motion

7. POINT TO POINT MOTION Used to position the tool at desired position. There are only two basic point to point motion commands GOTO/ GODLTA/

8. GOTO: The GOTO statement instructs the tool to go to a particular point location specified in the descriptive data. e.g . GOTO / P2 GOTO / 2, 7, 0 GODLTA: The GODLTA command specifies an incremental move for the tool. e.g. GODLTA / 2, 7, 0 instructs the tool to move from its present position to 2 units in x-direction, 7 units in y-direction and 0 units in z-direction.

9. CONTOURING MOTION In contouring motion commands the tool position must be continuously controlled throughout the move. For contouring movements, the tool is directed along intersecting surfaces. These surfaces have specific names in APT. i.e. Drive Surface (DS) Part Surface (PS) Check Surface (CS)

10. Drive Surface (DS): T he surface against which the edge of tool rides . Part Surface (PS) : The surface on which the bottom end of the tool rides. Check Surface (CS) : The surface at which the tool motion is stop .

11. HOW TO APPROACH THE CHECKSURFACE Modifier words, such as TO, ON, PAST or TANTO, are used to govern the position of the tool in relation to the check surface .

12. INITIAL CONTOURING MOTION STATEMENT GO/TO which defines the initial drive, part and check surfaces. It takes the form: GO/TO, drive surface, TO, part surface, TO, check surface An example would be: GO/TO, L1, TO, PL1, TO, L2 specifying that the tool should use line L1 as the drive surface, plane P1 as the part surface, and line L2 as the check surface.

13. MOTION COMMANDS GOLFT/ : Move left along the drive surface GORGT/ : Move right along the drive surface GOUP/ : Move up along the drive surface GODOWN/ : Move down along the drive surface GOFWD/ : Move forward from a tangent position GOBACK/ : Move backward from a tangent position

14. POST PROCESSOR STATEMENT MACHIN/ : use to specify the machine tool e.g.- MACHIN/DRILL,3 COOLNT/ : coolant fluid to be turned on or off. e.g.- COOLNT /ON FEDRAT/: feed rate for the tool in inch per min. e.g.- FEDRAT/4.5 SPINDL/: spindle rotation speed in rev per min. e.g.- SPINDL/ 850

15. AUXILIARY STATEMENTS These statements complete the APT programming language CUTTER/: specifies a quarter-inch cutter dia. e.g.- CUTTER/.25 FINI: end of program Tool tolerances. e.g.-INTOL/.0015 e.g.-OUTTOL/.001

16. EXAMPLE feed rate is 5.39 inches per minute; spindle speed is 573 rev per minute; coolant is to be used to flush the chips; the cutter dia is to be 0.5 inches, the tool home position is (0, -1, 0).

17. PARTNO MACHIN/MILL ,1 CUTTER/0.5000 P0 = POINT/0, -1.0, 0 P1 = POINT/0, 0, 0 P2 = POINT/6.0, 0, 0 P3 = POINT/6.0, 1.0, 0 P4 = POINT/2.0, 4.0, 0 L1 = LINE/P1, P2 C1 = CIRCLE/CENTER, P3, RADIUS, 1.0 L2 = LINE/P4, LEFT, TANTO, C1 L3 = LINE/P1, P4 PL1 = PLANE/P1, P2, P3 SPINDL/573 FEDRAT/5.39 COOLNT/ON FROM/P0 GO/PAST, L3, TO, PL1, TO, L1 GOUP/L3, PAST, L2 GORGT/L2, TANTO, C1 GOFWD/C1, ON, P2 GOFWD/L1, PAST, L3 RAPID GOTO/P0 COOLNT/OFF FINI PROGRAM

18. THANK YOU