LinuxCNC G61

G61 is a LinuxCNC G-code that selects exact path mode. In this mode the tool follows the programmed path exactly, slowing down or stopping as needed to reach every programmed point. If two sequential moves are exactly co-linear, movement does not stop between them.

Source checked3/3 values · 2026-10-26

Specification

1 source

Language	gcode
Code	G61
Syntax	G61
Dialect	LinuxCNC

Study notes

The document also defines G61.1 exact stop mode, where movement stops at the end of each programmed segment, and G64 path blending with optional P (blending tolerance) and Q (naive CAM tolerance); neither has a reference entry in this list.
G61 is a modal path control mode: it stays active until another path control mode is programmed.
The document recommends including a path control specification in the preamble of each G-code file.