# Description
The Ender-3 V3 SE machine start G-code performs its purge using
absolute-style extrusion positions:
```gcode
G1 ... E15
G1 ... E30
```
However, the machine start G-code does not explicitly initialize the
positioning or extrusion mode before these commands.
OrcaSlicer emits the printer's custom `machine_start_gcode` before its
own generated `G90` / `M82` or `M83` preamble. This means the purge can
inherit the extrusion mode left active by the printer.
For example, if `M83` relative extrusion is still active, such as after
a cancelled print where normal end G-code was not executed:
- `E15` extrudes 15 mm
- `E30` extrudes another 30 mm
Instead of the intended 15 mm followed by another 15 mm.
This change explicitly adds:
```gcode
G90 ;Absolute positioning
M82 ;Absolute extrusion mode
```
before the purge sequence so startup behaviour is deterministic and does
not depend on inherited printer state.
The change is applied consistently to all Ender-3 V3 SE nozzle variants:
- 0.2 mm
- 0.4 mm
- 0.6 mm
- 0.8 mm
No print speeds, temperatures, retraction values, machine limits, or
other profile settings are changed.
# Screenshots/Recordings/Graphs
Not applicable. This is a machine start G-code profile fix.
## Tests
- Confirmed all four Ender-3 V3 SE profiles use the same `E15` / `E30`
purge sequence.
- Confirmed the current profiles do not explicitly issue `G90`, `M82`,
or `M83` before that purge.
- Confirmed OrcaSlicer emits `machine_start_gcode` before its generated
positioning/extrusion-mode preamble.
- Verified the modified JSON for all four machine profiles parses
successfully.
- Verified the added commands make the purge explicitly use absolute XYZ
and absolute extrusion state.
