MASSO Documentation

G02 – Circular Interpolation (Clockwise)

This command runs a circular motion in a clockwise direction. The arc starts at the current position and the center is defined by the I, J values as an offset of the current position or R for radius. The X & Y values define the finish point. Masso uses Incremental I & J values for Arcs


Syntax & Parameters


  • G02 starts an arc movement beginning at the X & Y coordinate location where the G02 was issued.
  • X Value – This is the X coordinate defining the end point
  • Y Value – This is the Y coordinate defining the end point
  • I Value – are relative coordinates and define the X center coordinate as an offset of the starting point X coordinate.
  • J Value – are relative coordinates and define the Y center coordinate as an offset of the starting point Y coordinate.
  • Z Value - The addition of a Z value will describe a helical move.
  • R Value - Is used to define the arc radius for arcs up to 90 degrees. 


Caution: The use of R Value for arcs greater than 90 degrees do not work as it defines multiple centre points. For arcs greater that 90 degrees use IJK values for G02 commands.



Example program for making an Arc

N10 G00 X50 Y40 Z-1
N20 G02 X20 Y10 I-30 J0

  • In the above example in the first line moves to position X50 Y40 Z-1
  • An arc is made starting at position X50 Y40 and ending at coordinate X20 Y10 with center at position X20 Y40 moving in a clockwise direction. The Z height does not change.
  • The Arc center is calculated as follows
  • Starting position X50 + I-30 = Center X coordinate X20
  • Starting position Y40 + J0 = Center Y coordinate Y40