# Circular Interpolation

Circular moves are programmed with the codes G02 and G03.

G02 = circular interpolation clockwise.

G03 = circular interpolation anticlockwise.

In the following examples, there are five conditions that must be met before a G02 and a G03 can be programmed.

### 1st Condition

The tool must be at the precise start position.

### 2nd Condition

The next block control will control the direction the circular move will take G02/G03

### 3rd Condition

The block must also have the precise end position of the circular move X,Z

### 4th Condition

The block must establish the arc centre of the circular move. In an incremental coordinate system the circle centre is taken from the start position. The X centre is designated (I) and the Z axis centre is designated (K). The I and K values must have the precise figures of the circle centre coordinates programmed in this block.

### 5th Condition

After completing the circular move the G02/G03 must be cancelled if the next movement is linear with a G01 or G00

## Programming example with G02/G03 and I/K Incremental Circle Centre

N50 G00 X0 Z5 |

N60 G01 G42 Z0 |

N70 G01 X40 **(P1)** |

N80 G03 X50 Z-5 I0 K-5 **(P2)** |

N90 G01 Z-36 **(P3)** |

N100 G02 X58 Z-40 I4 K0 **(P4)** |

N110 G01 X74 **(P5)** |

N120 G03 X80 Z-43 I0 K-3 **(P6)** |

N140 G01 Z-80 |

N150 G01 G40 X82 |

N160 G00 X500 Z800 |

N170 M02 |