Easy G-Code Plot

Desktop G-code editor, analyzer, backplotter and trace exporter for FANUC-style turning and milling, with native SINUMERIK 840D milling support.

Project site: English · Русский See docs/PUBLISHING.md for local preview and GitHub Pages setup.

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What it is

Easy G-Code Plot models supported CNC program semantics and toolpath geometry. It is not a complete physical CNC-machine simulator.

The GUI, playback, statistics, stock-removal tools, CLI analysis and exporters all consume the same authoritative execution result produced by the shared CNC kernel:

G-code source
    |
    `--> Parser / controller frontend
           |- native Cython parser
           `- per-block Python fallback where required
                |
                v
             Program / AST
                |
                v
          Program tool setup
          (AST operation hints, library lookup, manual overrides)
                |- source comments / dimensions: Cython scanner
                `- Python scanner fallback
                |
                v
          CNC execution kernel
          (flow, cycles, compensation, geometry)
                |
                v
           ExecutionResult
                |
                +--> GUI rendering / playback
                +--> statistics
                +--> batch / CLI trace
                +--> EXPANDED postprocessor
                `--> DXF geometry

G-code source + execution map
                |
                `--> FULL source normalizer

The frontend constructs Program/AST once per shared execution. Tool setup consumes that same object before motion execution; the Cython/Python source scanner supplies literal tool candidates, comments and dimensions. Library lookup and manual overrides resolve the tool geometry, and the kernel owns execution semantics. FULL uses the exact source together with the authoritative execution map; EXPANDED and DXF consume resolved execution geometry/state. None of these paths implements a second CNC interpreter. Python fallback is supported in source checkouts, including individual complex blocks. Packaged releases require all three native extensions; missing extensions are explicit runtime errors.

Unsupported or ambiguous controller behavior is reported explicitly instead of being converted into guessed geometry.

Highlights

FANUC-style turning

Macro B expressions, conditions and loops, with bitwise AND/OR/XOR and LN/EXP.
G65 custom-macro calls and M98/M99 subprograms.
Turning cycles G70–G76.
G32, G33 and G92 threading.
Tool-nose compensation.
Direct A/C/corner-R programming.
Cutter-aware Stock Removal, including thread profiles.
Stock Removal follows executed motions and physical cutter geometry independently of the OD/ID/Face UI filters.
Thread-insert previews use a fixed contour with three 60-degree teeth, scaled only by diameter; P8 external tools point down and P6 internal tools point up. The thread-removal profile is calculated separately.

FANUC-style milling

Canned cycles and helical arcs.
G15/G16 polar-coordinate programming.
Cutter-radius compensation.
G10, G50, G51, G52, G54.1, G68 and G69 coordinate operations.
Indexed 3+2 milling with G68.2/G53.1.
Continuous five-axis TCP motion with G43.4 on supported angled AC/BC table profiles.
Indexed A/B milling and planar X/C contour mapping with selected rotary profiles.
Fixture coverage for 4ax_table_a, 4ax_table_b and 4ax_table_c.
Tapered ball-mill preview (TAPER_BALL_MILL).

SINUMERIK 840D

Native three-axis milling for .mpf / .spf.
Native G0/G1/G2/G3, CR=, work offsets, compensation and common tool/spindle/coolant commands.
G290/G291 native / ISO Dialect M switching.
Modal MCALL CYCLE81/82/83/84.
Native R parameters for the supported numeric subset.
GUI/CLI/kernel TRAORI/TRAFOOF TCP on the angled AC/BC table profiles, including G2/G3 with rotary interpolation.
Native CYCLE800 static frames and TRAORI/TRAFOOF TCP on angled AC/BC tables. Numeric A/B/C, direct R references and incremental IC values are supported for configured axes; DC selects the shortest absolute rotary approach; ambiguous half turns remain rejected.
TURN= multi-revolution arc handling.
EXPANDED serialization of resolved three-axis geometry between supported FANUC, SINUMERIK ISO-M and SINUMERIK native targets.

See SINUMERIK 840D for the exact supported subset and current limitations.

GUI and visualization

G-code editor with syntax highlighting, line numbers, search, replace and cleanup tools.
Interactive OpenGL toolpath.
Logical-motion playback with source-line synchronization.
Toolpath statistics: HTML summary, per-tool selector, metric/imperial display and Export HTML. Exported reports include a static SVG projection (XY milling, XZ turning) below the table. SVG uses Print page fitting and line styles, retaining every motion. CLI: python -m app analyze program.nc --html statistics.html.
HTML exports always use a light theme; the Statistics dialog follows the application theme. GUI report/program exports display their completion status. Playback highlights the current logical motion, including a whole arc, using the configured current-move color.
CNC editing assistants for hole patterns, pockets and reusable snippets.
ASCII and binary STL overlays with solid and feature-edge modes.
STL positioning, transforms, arrays, sections and statistics.
SQLite-backed turning and milling tool libraries.
Automatic saved-tool lookup by program T number, preserving manual program overrides. Operation-based fallbacks include native SINUMERIK CYCLE81–83 drills and CYCLE84 taps, classified from the controller AST.
English and Russian UI.
Light and Dark themes.
UTF-8 and Windows-1251 input.

Export and automation

Full Program export.
Expanded Execution export.
DXF export.
CLI parse, trace, analyze, batch, export and batch-export.
JSON and CSV batch reports.
Native Cython acceleration with compatible Python fallback.

Detailed controller behavior, limits, configuration and troubleshooting are documented in FAQ.md, also available through Help → FAQ.

The GUI sandbox runs one isolated four-program regression scenario or a paced visual demo, covering Options, Export, Stock Removal and STL Objects with an explicit final result.

Controller support overview

Area	FANUC-style	SINUMERIK 840D native
Turning	Yes	No
Three-axis milling	Yes	Yes
Macro / variable subset	Macro B	R parameters
Drilling / tapping cycles	Yes	`MCALL CYCLE81/82/83/84`
Indexed rotary milling	Yes	Angled AC/BC GUI/CLI/kernel numeric subset
Continuous TCP	`G43.4`, including rotary arcs	GUI/CLI/kernel `TRAORI` / `TRAFOOF`, angled AC/BC subset
Tilted working plane	`G68.2/G53.1`	`CYCLE800` axis-by-axis subset (GUI/CLI/kernel)
Native controller conversion	FANUC / ISO-M	Resolved native output
Batch analysis	Yes	Yes

CLEAN CLI status means that the supported execution model produced no diagnostics. It is not machine validation.

SINUMERIK 840D

Input modes

Every .mpf / .spf file is treated as a SINUMERIK container.

Native mode is the default.
Standalone G290 selects native Siemens syntax.
Standalone G291 selects ISO Dialect M.
CLI commands still use --lang fanuc_mill for the common milling geometry model.

MPF/SPF documents retain the selected rotary-kinematics profile. Settings and Options expose the enabled profiles; native CYCLE800/TRAORI require a supported angled AC/BC table. The kernel rejects incompatible axes, profiles and ISO-M rotary commands.

Native subset

Native support currently includes:

G0/G1/G2/G3
CR=
plane selection
absolute / incremental positioning
metric G710
work offsets
G40/G41/G42
D0..D12
tool, spindle and coolant commands
G0 SUPA, including configured A/B/C rotary axes (absolute even under G91); zero XYZ addresses use the application's configured G28/SUPA return position, shared with FANUC G53
MSG
WORKPIECE
G64
semicolon comments

MSG, WORKPIECE, G64 and comments do not generate phantom geometry.

CYCLE800 uses Siemens bit-coded axis order, not FANUC Euler ZXZ. Modes 57/54/39/27/30/45, ST200000 (new)/200001 (additive), DIR-1/0/1, quoted TISCH/empty data-set names and numeric/direct R arguments are supported on angled AC/BC tables. DIR selects the principal first-table-joint branch; 0 calculates the frame without indexing. Reset uses CYCLE800(), bare CYCLE800, or a zero frame with TC="0" (ST200000 or compatibility ST110000). FR0/1/2 are accepted as logical retract requests: OEM machine retract paths are not simulated. FR_I must be empty/zero; DMODE0/1 is supported. Other options and arbitrary OEM data sets reject.

R parameters

The supported native subset accepts numeric assignments such as:

R1=500
R2=6000

and references in supported addresses and cycles, including:

F=R1
S=R2
X=R1
CR=R1
TURN=R1

R state is separate from FANUC # variables and resets for each execution.

Undefined references, arithmetic/control flow, arrays and Siemens system variables are outside the current subset.

MCALL cycles

Modal MCALL CYCLE81/82/83/84 expands supported numeric parameters into resolved motions. Bare MCALL cancels the active cycle.

CYCLE84 implements the supported CAM-oriented single-pass metric right-hand tapping subset. It models trajectory and logical spindle signals, not spindle-angle simulation.

See FAQ.md and FAQ_RU.md for exact parameter constraints.

TURN=

TURN=n supports integer values from 0 to 999 for supported G2/G3 arcs using IJK or CR=.

The kernel keeps a single resolved arc with the complete sweep. Rendering, playback and statistics preserve all revolutions. DXF uses sampled polylines when required.

Current kinematic limit

Native XYZ geometry and modal cycles are supported; the GUI/CLI/kernel also accepts the bounded TCP subset below.

GUI/CLI/kernel TRAORI/TRAFOOF supports TCP on the angled AC/BC table profiles, including Cartesian G2/G3 arcs with rotary interpolation. Numeric A/B/C assignments and direct R references are supported only for configured axes. CYCLE800 supports the bounded static-frame subset described above. IC(numeric/direct R) is incremental independently of G90/G91; CUT3DC and FL[] remain explicitly unsupported. GUI profile selection reaches the same kernel and plotting path.

D0 cancels edge selection; D1 through D12 select an edge while retaining nominal tool geometry. Edges above D1 report UNVERIFIED_SINUMERIK_EDGE_OFFSETS because controller offset tables are unavailable. CYCLE800 ST220000/220001 compute a new/additive frame without indexing. The DMG frame-only data-set name is accepted on 5ax_table_bc_angled with FR0; OEM indexing remains unsupported.

Native acceleration

Contiguous literal position blocks can use the Cython execution path. The Python capability gate runs before state changes.

Native declarations, G290/G291 switches and controller operations break an accelerated run; later eligible blocks can resume acceleration. Blocks under active native cycles stay on the Python reference path until the cycle is cancelled.

Export model

The GUI and CLI expose three export families: FULL, EXPANDED and DXF.

FULL is a source-preserving NC normalizer. It keeps ordinary source blocks, comments, controller dialect, modal commands and supported cycles. Constructs whose meaning depends on labels or execution flow are unfolded from the authoritative execution map before sequence numbers can be changed: FANUC Macro B / evaluated variables, IF/GOTO/WHILE flow, G65 and M98/M99 calls, and FANUC turning G70–G76. FULL is not a controller-conversion mode.

EXPANDED is one universal serializer of the resolved execution. Target CNC selects the target syntax and post profile; the bundled profiles are fanuc_mill, fanuc_mill_multiaxis, fanuc_lathe_a, fanuc_lathe_b, sinumerik_iso, sinumerik_840d and sinumerik_840d_multiaxis, and a JSON path can be supplied with --post-profile. Auto (source controller) selects the profile matching the source controller and dialect. Profiles define syntax, mandatory frames, capabilities and defaults, but they do not disable user output options: coordinates, sequence numbers, delimiter, leading zero, modal feed, decimal precision, force decimal, plus sign, arc output and start/end program text remain available and are honored for FANUC→FANUC, FANUC→SINUMERIK ISO, FANUC→SINUMERIK native and SINUMERIK→FANUC. A profile default is used only when the user did not choose a value.

Expanded arcs can be emitted as relative IJK, absolute IJK, radius or linearized motion. The profile defines the controller spelling: native SINUMERIK uses I=AC(...) / J=AC(...) / K=AC(...) for absolute centers and CR= for radius output, while FANUC/ISO profiles use their configured IJK/R forms. Source comments are preserved through the post's comment template. Native SINUMERIK emits its G290/G291 language mode as the physically first program line, and user start text is emitted after it.

EXPANDED output is modal by default: Modal Feed controls whether F is restated (Yes only when the feed value or feed mode changes, No on every cutting motion). Safety Line emits the profile-declared program.safety block after the user start text. Word order and mandatory output are controlled by the post profile's format.words: each token (motion, X, Y, Z, A, B, C, I, J, K, R) has an order and a required flag. required forces an address to be emitted even when unchanged or zero (for example Y0); motion.required=false makes the motion code modal. Per-word decimals/sign live in the same object, and an axis entry is only valid when the axis is declared in supports.axes. F is intentionally not part of format.words because feed is managed by Modal Feed. Other profile sections (format.turnsWord/radiusSplitAngle/arcSplitAngle/fullCircle, and supports declaring axes/inverseTime/multiTurnArcs/absoluteArcCenters) keep working and make unsupported requests fail closed as UNSUPPORTED instead of writing partial NC. Multi-axis geometry (rotary A/B/C, G68.2/G53.1, G43.4, CYCLE800, TRAORI/TCP) remains unsupported by the three-axis postprocessor and is reported as a limitation, not an error.

Cycles, variables and subprogram flow are already executed before EXPANDED serialization. Physical XYZ is emitted in one zero-offset G54 frame. Actual rotary/TWP/TCP geometry is rejected by the three-axis postprocessor; merely having a kinematics profile selected does not make an otherwise XYZ-only program rotary. Reference returns are emitted through the target profile (G28/G53 or native SUPA) and unresolved position gaps fail closed.

DXF writes the available resolved motion geometry without NC formatting or controller postprocessing. Rapid and cutting moves use separate layers. Planar arcs/circles are written analytically where representable; helices and multi-revolution geometry are sampled as polylines when required. Turning uses the plot-aligned Z/X view.

Examples from a source checkout:

.\easy_gcode_plot_cli.exe export source.nc --lang fanuc_mill --mode full --sequence-numbers -o normalized.nc
.\easy_gcode_plot_cli.exe export source.nc --lang fanuc_mill --mode expanded --post-profile app\gcode\export\posts\sinumerik_840d.json -o posted.mpf
.\easy_gcode_plot_cli.exe export source.nc --lang fanuc_mill --format dxf -o toolpath.dxf

The GUI exposes the same FULL / EXPANDED / DXF split in the Export Data dialog. Target-controller selection belongs to EXPANDED (including Auto (source controller)); FULL keeps the source controller/dialect. The GUI, single-file export and batch-export all use the same export contract and conversion code, so CLI and batch output matches the GUI for the same settings.

Quick start

Windows release

Download the GUI executable and easy_gcode_plot_cli.exe from GitHub Releases.

Python and Visual Studio are not required for packaged applications.

.\easy_gcode_plot_cli.exe --help
.\easy_gcode_plot_cli.exe analyze program.nc --lang fanuc_turn
.\easy_gcode_plot_cli.exe batch C:\Programs --lang fanuc_mill -o C:\Reports

Linux release

Download the Linux x64 archive and matching .sha256 file.

sha256sum -c Easy-G-Code-Plot-*-Linux-x64.tar.gz.sha256
tar -xzf Easy-G-Code-Plot-*-Linux-x64.tar.gz

./easy_gcode_plot
./easy_gcode_plot_cli --help

Run from source

Requirements:

Python 3.13+
uv
C compiler:
- Visual Studio Build Tools with Desktop development with C++ on Windows
- platform compiler and Python development headers on Linux

git clone https://github.com/MaestroFusion360/easy_gcode_plot.git
cd easy_gcode_plot

uv sync --no-dev
uv run --no-dev python main.py

uv sync builds the tracked Cython .pyx sources. Generated .c, .pyd and .so files are not stored in Git.

If native extensions cannot be loaded, the application remains functional through the slower Python fallback.

GUI workflow

Open or drag a .nc, .cnc, .ptp, .mpf, .spf or .txt program into the application.
Enable Lathe Mode for turning, or leave it disabled for milling.
Configure WCS, machine home and tools when required.
For indexed FANUC milling, select the matching Settings → Rotary kinematics profile.
Refresh and inspect the resolved toolpath.
Use playback, Tokens/Macro Variables and Statistics to inspect execution.
Optionally import an STL reference model.
Export the required program or trajectory representation.

File → Print (Ctrl+P) produces a page-fitted vector drawing in the current camera orientation.

CNC editing assistants

The CNC Functions menu and toolbar provide:

Hole Calculator — circular or serpentine rectangular hole patterns with live XY preview.
Pocket Calculator — circular or rectangular milling fragments with multiple depths, stock, conventional/spiral clearing, helical entry and optional finish pass.
Snippets — reusable persistent G-code fragments stored in the per-user SQLite database.

Hole and Pocket calculators are milling-only assistants.

The calculators insert code into the editor; they do not execute or export it automatically. Refresh the toolpath after reviewing the generated block.

STL overlays

ASCII and binary STL models can be used as visual references.

The Settings → STL Objects panel supports:

independent undo/redo
base-point and bounding-box picking
positioning and transforms
circular and rectangular arrays
3D sections
copyable statistics
millimetre / inch display

Solid STL mode can hide toolpath segments that are behind the model surface.

Tool Library

Settings → Tool Library manages separate milling and turning tool sets.

Current Program contains temporary T-slot assignments discovered or configured for the open program.
Saved Library contains persistent tools stored in the per-user tools.db.

Literal T selections, comments and operation context can infer tool descriptions and geometry. Program discovery never modifies the saved library automatically.

The turning library supports:

Diamond 80
Diamond 35
Square
Round
Triangle
Groove
Thread
Drill
Tap

OD, ID and Face are separate application flags.

JSON and CSV export write the complete working library for the active machine type.

CLI

The CLI uses the same CNC kernel as the GUI.

Common commands

.\easy_gcode_plot_cli.exe parse program.nc --lang fanuc_turn

.\easy_gcode_plot_cli.exe trace program.nc --lang fanuc_turn -o trace.json

.\easy_gcode_plot_cli.exe analyze program.nc --lang fanuc_turn

.\easy_gcode_plot_cli.exe batch .\programs --lang fanuc_mill -o batch-report

.\easy_gcode_plot_cli.exe export program.nc --lang fanuc_turn -o expanded.nc

.\easy_gcode_plot_cli.exe batch-export .\programs --lang fanuc_mill --mode expanded -o normalized

Indexed example:

.\easy_gcode_plot_cli.exe analyze indexed.nc --lang fanuc_mill --kinematics 4ax_table_b

SINUMERIK examples:

.\easy_gcode_plot_cli.exe analyze part.mpf --lang fanuc_mill

.\easy_gcode_plot_cli.exe export part.mpf --lang fanuc_mill --mode expanded --post-profile app\gcode\export\posts\fanuc_mill.json -o part.nc

.\easy_gcode_plot_cli.exe export fanuc_part.nc --lang fanuc_mill --mode expanded --post-profile app\gcode\export\posts\sinumerik_840d.json -o part.mpf

Batch analysis

batch scans recursively by default.

Without --lang, each .mpf/.spf file selects milling SINUMERIK; other files keep the turning default. An explicit --lang applies to all files.

Use the shared single-file statistics/HTML API for every program:

.\easy_gcode_plot_cli.exe batch .\programs --html .\reports\html -o .\reports

This writes one HTML report with a tool selector and XY/XZ SVG per input, alongside the JSON/CSV summary. Relative directories and complete input names are preserved (sub/part.mpf → html/sub/part.mpf.html). Add --inches for imperial display. Each source is executed once; failed/partial execution still produces its statistics report. An unreadable input has diagnostics in JSON/CSV. HTML write errors are reported per file without stopping the batch.

Default recognized extensions:

.nc .cnc .ptp .mpf .spf .tap .txt

FANUC programs without a conventional NC extension can also be discovered from their first blocks when default discovery is used.

Reports:

batch_report.json
batch_report.csv

Per-file status:

CLEAN
WARNINGS
ERRORS

An empty scan produces NO_FILES.

Reports include diagnostics, motion/executed-block counts and unknown or unsupported G/M codes.

Use:

--extensions .nc,.mpf

to restrict file types, or:

--top-level-only

to disable recursive scanning.

Batch export

batch-export writes a mirrored output tree plus:

batch_export_report.json
batch_export_report.csv

Source files are never modified.

The same single-file export contract backs export, batch-export and the GUI, so the same settings produce the same output. The four preset conversion scripts below are covered by a semantic regression gate (tests/export/test_batch_export_semantics.py) that re-executes successfully exported programs and compares their trajectory signature with the source.

Files with invalid or incomplete execution are skipped while the remaining inputs continue.

For mixed indexed batches, --kinematics-map can assign a profile per relative input path.

Preset conversion scripts

The development tree contains four EXPANDED batch-export checks. They use the built CLI and explicit JSON post profiles, writing below tmp/test_export.

Windows:

.\scripts\ps1\batch\fanuc_mill_to_sinumerik_native.ps1
.\scripts\ps1\batch\fanuc_mill_to_sinumerik_iso.ps1
.\scripts\ps1\batch\fanuc_lathe_a_to_b.ps1
.\scripts\ps1\batch\sinumerik_native_to_fanuc_mill.ps1

Linux:

bash scripts/sh/batch/fanuc_mill_to_sinumerik_native.sh
bash scripts/sh/batch/fanuc_mill_to_sinumerik_iso.sh
bash scripts/sh/batch/fanuc_lathe_a_to_b.sh
bash scripts/sh/batch/sinumerik_native_to_fanuc_mill.sh

Run:

.\easy_gcode_plot_cli.exe --help

or:

.\easy_gcode_plot_cli.exe batch --help

for the complete command-line reference.

Settings

The main execution settings are under Settings → Options.

General

Language
Theme
Auto Update
Auto update max segments
Maximum generated motions
Toolbar icon size

CNC / Execution

Autodetect Arc Type
Ignore Block Skip
G41/G42 correction
Arc tolerance
Arc sampling preset
Maximum / minimum circular radius
Minimum chord length

Sampling controls affect GUI trace representation without changing the resolved CNC execution geometry.

Explicit Refresh operations are cancellable.

Development

Install development dependencies and run the standard checks:

uv sync --group dev

uv run pytest
uv run ruff check .
uv run ruff format --check .

Build helpers are available for both platforms:

Task	Windows PowerShell	Linux shell
Tests	`.\scripts\ps1\test.ps1`	`bash scripts/sh/test.sh`
Lint	`.\scripts\ps1\lint.ps1`	`bash scripts/sh/lint.sh`
Native extensions	`.\scripts\ps1\build-native.ps1`	`bash scripts/sh/build-native.sh`
PyInstaller package	`.\scripts\ps1\build.ps1`	`bash scripts/sh/build.sh`

Linux CLI build:

bash scripts/sh/build.sh --console --skip-tests
./dist/easy_gcode_plot_cli --help

Native and release builds use the separate .venv-build environment and rebuild when tracked Cython sources change.

The CNC kernel lives under:

app/gcode/kernel/

Exporters consume the kernel's authoritative execution result instead of interpreting G-code again.

New CNC semantics belong in the kernel and should be covered by deterministic regression tests.

See FAQ.md for package structure, Qt generation, detailed settings and release notes.

License

MIT License — see LICENSE.md.

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
.vscode		.vscode
app		app
docs		docs
scripts		scripts
stl		stl
tests		tests
translations		translations
.gitattributes		.gitattributes
.gitignore		.gitignore
.python-version		.python-version
CHANGELOG.md		CHANGELOG.md
FAQ.md		FAQ.md
FAQ_RU.md		FAQ_RU.md
LICENSE.md		LICENSE.md
README.md		README.md
cli_main.py		cli_main.py
logo.ico		logo.ico
main.py		main.py
pyproject.toml		pyproject.toml
uv.lock		uv.lock

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Easy G-Code Plot

What it is

Highlights

FANUC-style turning

FANUC-style milling

SINUMERIK 840D

GUI and visualization

Export and automation

Controller support overview

SINUMERIK 840D

Input modes

Native subset

R parameters

MCALL cycles

TURN=

Current kinematic limit

Native acceleration

Export model

Quick start

Windows release

Linux release

Run from source

GUI workflow

CNC editing assistants

STL overlays

Tool Library

CLI

Common commands

Batch analysis

Batch export

Preset conversion scripts

Settings

General

CNC / Execution

Development

License

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