E5S1 G-code Post-Process

G-code post-processor tuned for the Creality Ender-5 S1 with a 0.8 mm high-flow nozzle (Spider hotend). Not a generic slicer profile — speed caps, fan curves, retraction, pressure advance, and skirt geometry assume this printer and nozzle size.

PrusaSlicer supplies sliced geometry; this pipeline injects machine-specific fan ramps, flow tuning, seam handling, pressure advance, startup repair, and skirt adhesion.

No external config bundle required — defaults live in code for Ender-5 S1 @ 0.8 mm, with optional overrides from the prusaslicer_config block embedded in exported G-code.

Stack

• Python 3.11+ (stdlib only — no third-party dependencies)
• PrusaSlicer 2.x (post_process hook)
• Target printer: Creality Ender-5 S1, 0.8 mm nozzle
• Target firmware: Marlin (Klipper auto-detected when present)

Quick setup

git clone https://github.com/LuizEduPP/e5s1-gcode-postprocess.git
cd e5s1-gcode-postprocess
python3 -m venv .venv
source .venv/bin/activate   # Windows: .venv\Scripts\activate

In PrusaSlicer → Print Settings → Output options → Post-processing scripts, add:

python3 /absolute/path/to/scripts/gcode_postprocess.py

Use the absolute path to gcode_postprocess.py. PrusaSlicer passes the exported G-code file path as the first argument on every slice.

Environment variables

Variable	Required	Description
E5S1_EXPORT_DIR	No	Extra folder to scan for recent post-processed exports (default: ~/Downloads, ~/Documents, ~/Documentos)

Machine tuning for the Ender-5 S1 / 0.8 mm setup is in scripts/profile.py (retraction, fan curves, PA, skirt, seam). Slicer-exported values override defaults when present in the G-code tail block. Other printers or nozzle sizes require editing those constants.

Commands

Post-process one or more files manually (verbose output):

python3 -c "
import sys
from pathlib import Path
sys.path.insert(0, 'scripts')
from gcode_pipeline import run_postprocess
sys.exit(run_postprocess([Path('model.gcode')], quiet=False))
"

PrusaSlicer entry point (quiet, used automatically after each export):

python3 scripts/gcode_postprocess.py /path/to/model.gcode

Logs and last-run state are written to logs/ (gitignored).

Architecture

gcode_postprocess.py     PrusaSlicer entry — forwards to pipeline
        │
gcode_pipeline.py        File I/O, skip-if-processed, validation, logging
        │
        ├── gcode_checks.py      Analysis (layers, support, overhangs) + validation
        ├── gcode_export.py      Recent export discovery for state hints
        └── gcode_transform.py   Main line-by-line transform loop
                │
                ├── profile.py           E5S1 defaults + prusaslicer_config merge
                ├── gcode_tune.py          Fan / seam / speed / retraction tuning
                ├── gcode_repair.py        Startup fix, skirt injection, PA (M900)
                ├── gcode_features.py      ;TYPE feature classification
                ├── gcode_emit.py          Injected G-code line builders
                ├── gcode_patterns.py      Shared regex + strip helpers
                └── config.py              Markers, TYPE tags, scan limits

Flow: read G-code → parse optional ; prusaslicer_config tail → build runtime profile → transform (fan ramp, flow, caps, seams, bridges) → repair startup/skirt/PA → validate → write in place.

Idempotency: files containing ; --- E5S1 postprocess --- are skipped unless re-run with force=True in the pipeline API.

Hardware profile (defaults)

Calibrated for Ender-5 S1 + 0.8 mm nozzle. Values below are the built-in baseline in profile.py:

Parameter	Value
Printer	Creality Ender-5 S1
Nozzle	0.8 mm (high-flow / Spider)
First layer height	0.24 mm
Fan off layers	2
Full fan layer	5
Pressure advance (pa_k)	0.08
Skirt	3 loops, 40 mm side, origin (3, 3) mm

License

MIT — see LICENSE.