Datum Setting

Dart 21i MArrow 18i MSabre 18i MLancer 18i M

Datum Setting with a edge finder of a known radius

The objective is to inform the NC control the distance from the machine co-ordinateto the datum position in the X & Y axis (spindle centreline) and the distance from the

machine co-ordinate to the datum position in the Z axis (spindle nose).

Machine Table (Front View)

Plan View

G54 Y?

G54 X?

G54 Z?

Workpiece

Workpiece

Datum Edge Location1) Using the handwheel, position the edge finder on the X axis side of the workpiece.

2) Select hard key <OFFSET SETTING>3) Select soft screen key <WORK>4) Using the arrow keys up and down select the required setting offset. Choose from

G54 – G59 (Not EXT).5) Type current program position from datum edge to spindle centreline e.g. X-5 (as

per drawing example).6) Select <MEASURE> soft screen key.

The value now contained in the X axis table will be the distance from the machine co-ordinate to the datum edge.

Edge finder (5mm Rad.)

TableX offset

Required datum point

Radial offset X-5

X- X+

Y+

Y-

7) Now using the handwheel, lift the Z axis clear of the workpiece surface. Positionthe edge finder on the Y axis side of the workpiece.

8) Select hard key <OFFSET SETTING>9) Select soft screen key <WORK>10) Using the arrow keys up and down select the required setting offset. Choose from

the same offset setting system (Not EXT).11) Type current program position from datum edge to spindle centreline e.g. Y-5 (as

per drawing example).12) Select <MEASURE> soft screen key.

The value now contained in the Y axis table will be the distance from the machine co-ordinate to the datum edge.

Edge finder (5mm Rad.)

Table

Required datum point

X- X+

Y+

Y-

Y offset

Radial offset Y-5

13) Return setting tool to the tool drum using MDI and T0 M6; Insert14) Using the handwheel, position the spindle nose to a setting block of a known

height on top of the required datum in the Z axis.

15) Select hard key <OFFSET SETTING>16) Select soft screen key <WORK>17) Using the arrow keys up and down select the required setting offset. Choose from

the same offset setting system as X & Y (Not EXT).18) Type current program position from datum edge to spindle centreline e.g. Z100 (as

per drawing example).19) Select <MEASURE> soft screen key.

The value now contained in the Z axis table will be the distance from the machine co-ordinate to the datum edge (& should be a negative Z axis value).

Spindle

Workpiece surface

100mm

Centre of workpiece Datum Location1) Using the handwheel, position the edge finder on the X axis side of the workpiece.

2) Select hard key <POSITION>3) Select soft screen key <RELATIVE>4) Select X on the alpha keyboard (X on the screen should start to flash).5) Select soft screen key <ORIGIN> (X axis on the screen will show zero).6) Using the handwheel move the Z axis above the workpiece surface.7) Using the handwheel, position the edge finder on the other side of the X axis of

the workpiece.

Table

Required datum point

Edge locator

Table

Required datum point

Edge locator

8) Select hard key <OFFSETS>9) Select screen soft key <WORK>10) Using the arrow keys up and down select the required setting offset. Choose from

G54 – G59 (Not EXT).11) Type current program position from datum to spindle centreline which is shown as

the “RELATIVE X axis position divided by 2”.12) Select <MEASURE> soft screen key.

The value now contained in the X axis table will be the distance from the machine co-ordinate to the datum position.

13) Now using the handwheel, lift the Z axis clear of the workpiece surface. Positionthe edge finder on the Y axis side of the workpiece and follow the steps from 1-12above.

14) Return setting tool to the tool drum using MDI and T0 M6; Insert15) Using the handwheel, position the spindle nose to a setting block of a known

height on top of the required datum in the Z axis.

16) Select hard key <OFFSET SETTING>17) Select soft screen key <WORK>18) Using the arrow keys up and down select the required setting offset. Choose from

the same offset setting system as X & Y (Not EXT).19) Type current program position from datum edge to spindle centreline e.g. Z100 (as

per drawing example).20) Select <MEASURE> soft screen key.

The value now contained in the Z axis table will be the distance from the machine co-ordinate to the datum edge (& should be a negative Z axis value).

Spindle

Workpiece surface

100mm