G3: counter-clockwise arcs
G3 is the mirror of G2: the same arc geometry travelled counter-clockwise. It parses and converts, but nothing in the proven reference file exercises it.
Syntax
G3 X<mm> Y<mm> I<mm> J<mm> [V<feed>]UnverifiedThe encoding is confirmed by the reference programs, but no file of ours in this shape has been run on a machine. Produced with a warning, refused in strict mode.
Parameters
X | X coordinate of the end point in millimetres | required |
Y | Y coordinate of the end point in millimetres | required |
I | X coordinate of the arc centre | required |
J | Y coordinate of the arc centre | required |
V | Feed rate | optional |
How it is written to PGM
A counter-clockwise arc is its own command with its own code, and the record is the same 28 bytes as a clockwise one. The earlier reading of this format, in which direction was a bit inside a shared record, was wrong: the two are separate commands, as 116 reference programs show.
Example
G3 X392.609 Y93.798 I405.117 J154.117Notes
- Like G2, all four of X, Y, I and J are required.
- In strict mode a program containing a G3 is refused rather than converted.
- A sample pair containing a G3 would turn this encoding from a guess into a verified one.
Messages this command can produce
- Counter-clockwise arc not yet run from our outputUnverified
- Arc without a centreParse error
- Cutting before any depth was setUnsupported
- Depth change after the first depthUnverified