[Marlin] G002-G003 - Arc or Circle Move
📅Update: 2020/09/18
G2
adds a clockwise arc move to the planner; G3
adds a counter-clockwise arc. An arc move starts at the current position and ends at the given XYZ, pivoting around a center-point offset given by I
and J
or R
.This command has two forms:
I
specifies an X offset.J
specifies a Y offset.- At least one of the
I
J
parameters is required. X
andY
can be omitted to do a complete circle.- The given
X
Y
is not error-checked.The arc ends based on the angle of the destination. - Mixing
I
orJ
withR
will throw an error.
R
specifies the radius.X
orY
is required.- Omitting both
X
andY
will throw an error. X
orY
must differ from the current XY position.- Mixing
R
withI
orJ
will throw an error.
Arc moves actually generate several short straight-line moves, the length of which are determined by the configuration option
MM_PER_ARC_SEGMENT
(default 1mm). Any change in the Z position is linearly interpolated over the whole arc.'ARC_P_CIRCLES' enables the use of the 'P' parameter to specify complete circles
G2
[E<pos>]
I<offset>
J<offset>
[P<rate>]
R<radius>
[X<pos>]
[Y<pos>]
[Z<pos>]
[E<pos>]
The amount to extrude between the start point and end pointI<offset>
An offset from the current X position to use as the arc centerJ<offset>
An offset from the current Y position to use as the arc center[P<rate>]
Specify complete circles - requiresARC_P_CIRCLES
R<radius>
A radius from the current XY position to use as the arc center[X<pos>]
A coordinate on the X axis[Y<pos>]
A coordinate on the Y axis[Z<pos>]
A coordinate on the Z axis
This illustrates a counter clockwise arc, starting at [9, 6]. It can be generated either by
G3 X2 Y7 I-4 J-3
or G3 X2 Y7 R5

avatar
Move in a clockwise arc from the current position to [125, 32] with the center offset from the current position by (10.5, 10.5).
G2 X125 Y32 I10.5 J10.5
Move in a counter-clockwise arc from the current position to [125, 32] with the center offset from the current position by (10.5, 10.5).
G3 X125 Y32 I10.5 J10.5
Move in a complete clockwise circle with the center offset from the current position by [20, 20].
code: G2 I20 J20
Last modified 2yr ago