Drilling with Ultimate CNC and Grbl

Grbl don't support drilling cycle, for this reason, the Ultimate CNC translate it to G-code that Grbl can understand like G00 or G01.

Nowadays, using Ultimate CNC you will have drilling drilling functionality through G81 and G82 code in your CNC machine using Grbl.

You need consider that G81 and G81 are modal commands, then they’ll stay active until you turn them off with G80 Without it, the cycle will repeat at every XY coordinate.

G81: Drilling Cycle with Grbl

The tool positions itself at the top of the hole. The tool feeds to the specified Z position at the programmed feed rate. The tool retracts in rapid mode to either the previous Z position or the R plane.

G81 X1 Y0 Z-0.5 R1 L4

Values:

  • X: The X location of the first hole.

  • Y: The Y location of the first hole.

  • Z: The depth of the first hole (absolute).

  • R: Retract.

  • F: Feedrate. If nothing is input, then the last used feedrate will be used.

  • L: Number of times to repeat.


Sample Code:


G90 G0 X0 Y0 Z0 G01 F10 X0 G4 P0.1 G91 G81 X1 Y0 Z-0.5 R1 L4 X0 Y1 R0 L3 X-1 Y0 L3 X0 Y-1 L2 G80 G90 G0 X0 Y0 Z0 M2

G82: Drilling Cycle, Dwell with Grbl

G82 X1 Y0 Z-0.5 R1 L4 P1

Values:

  • X: The X location of the first hole.

  • Y: The Y location of the first hole.

  • Z: The depth of the first hole (absolute).

  • R: Retract.

  • F: Feedrate. If nothing is input, then the last used feedrate will be used.

  • L: Number of times to repeat.

  • P: Dwell, number of seconds