G71

⌨Format and notes

G71 U_ (depth of cut, radius value) R_ (retract amount);
G71 P_ Q_ U_ (X finishing allowance, diameter value) W_ (Z finishing allowance) F_ S_ T_

• Two-block format. U in the first line is the depth of cut and U in the second line is the X finishing allowance; the same address has different meanings (distinguished by the presence of P/Q)
• The sign of the finishing allowance U/W depends on the cutting quadrant (OD or ID, direction of Z)
• The profile is basically one where X is monotonic and never reverses direction (Type I). Profiles with recesses can use Type II, only on machines that support it
• After G71, write G70 with the same P/Q to finish

≠Differences between controls and machines

The same code can be written or assigned differently depending on the CNC control and the machine builder. Always check your machine’s manual.