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LinuxCNC G86

G86 is a LinuxCNC canned boring cycle. It feeds the Z axis to the programmed depth, dwells for P seconds, stops the selected spindle, rapid-retracts to clear Z, then restarts the spindle in its previous direction.

Source checked23/23 values · 2026-10-26

Specification

1 source
Languagegcode
CodeG86
Groupcanned cycles
SyntaxG86 (X- Y- Z-) or (U- V- W-) R- L- P- $-
DialectLinuxCNC

Parameters

NameDescription
XAxis word from the XYZ group; used when the active plane requires XYZ.
YAxis word from the XYZ group; used when the active plane requires XYZ.
ZAxis word from the XYZ group; used when the active plane requires XYZ.
UAxis word from the UVW group; used when the active plane requires UVW.
VAxis word from the UVW group; used when the active plane requires UVW.
WAxis word from the UVW group; used when the active plane requires UVW.
RRetract position along the axis perpendicular to the selected plane.
LNumber of repeats; optional, and L=0 is not allowed.
PDwell time in seconds.
$Selected spindle; chooses which spindle is stopped.

Study notes

  • G86 is a boring canned cycle that uses a P number for the number of seconds to dwell.
  • Sequence: feed the Z axis to the Z position, dwell for P seconds, stop the selected spindle, rapid move to clear Z, then restart the spindle in the direction it was going.
  • Preliminary and in-between motion is shared with other canned cycles in the G80-G89 family.
  • Canned cycles use X Y Z or U V W depending on the active plane; rotary axis words are not allowed in canned cycles.
  • G80 or another modal group 1 G-code cancels a canned cycle.

Safety

  • The spindle must be turning before G86 is executed; otherwise LinuxCNC reports an error.
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