NC 3D Print

Version 1.61.0 · Nextcloud 28–34 · PHP 8.1+ · License AGPL-3.0-or-later

A standalone Nextcloud app for the full prepare → slice → print workflow. It ships and owns its own headless slicing engine (an OrcaSlicer fork, run as the nc-print-slicer sidecar container) and pairs it with Moonraker/Klipper for a Mainsail/Fluidd-class monitoring and control experience — without leaving your Nextcloud, and with no external slicer service and no NC-GCS dependency.

What it does

Prepare

• Three.js model viewport (STL / OBJ / 3MF) with a Z-up bed grid and bounding-box overlay
• Operator-speed model prep — one-click "Ready to print" (auto-orient → center → drop), arrow-key nudging (1 / 10 / 0.1 mm), Ctrl+D duplicate, gizmo snap presets, and bed exclusion zones with pre-slice overlap warnings
• Interactive transform gizmos (move / rotate / scale) plus lay-flat, auto-orient, place-on-face, mirror, and plane-cut tools — the mesh you see is the mesh that slices (WYSIWYG, no "blind" slices)
• Printer / filament / process profile pickers with quick-edit override settings
• Target printer picker on Prepare — select or scan the Moonraker machine you will send to (distinct from the slicer printer profile); gates Prepare → Slice
• Mesh health check (triangles, open edges, watertight)

Slice (self-contained — no external slicer)

• Real headless slicing in the owned nc-print-slicer sidecar, streamed to the browser over SSE with live progress
• Override settings (layer height, line width, perimeters, infill, speeds, temps, retraction, supports, brim/raft/skirt) that actually take effect
• 3D toolpath preview — inspect the printed paths after slicing with per-feature colours, a layer slider, and toggleable travel moves
• Multi-object plates — add several models and auto-arrange them on one plate, each with optional per-object settings (walls, layer height, infill %, pattern, supports) that override the global slice settings for that model only
• Smart ETA (learned) — after each print the app learns this printer's slicer-vs-actual delta (an EWMA multiplier per printer/material/nozzle) and shows a corrected "predicted" time alongside the slicer estimate on the slice result, with a confidence figure
• Calibration suite — one-click flow-rate models, a parametric temperature tower, plus seven procedural generator prints (temp/retract/flow/ pressure-advance towers, a PA pattern, first-layer patch, and single-line max-flow test) that emit tuning G-code directly with no slice needed
• Pause / filament change at height — insert M600 (filament change) or M601 (pause) at chosen Z heights, for multi-colour prints, embedding hardware, or inspection
• Multi-colour purge optimizer — enter the plate's filament colours and get the load order that minimises total purge, using OrcaSlicer's flush model (asymmetric — switching to a lighter colour wastes more); shows grams saved vs loading as listed
• Material breakdown + cost — model vs support filament (g) and estimated cost, computed per feature from the sliced G-code
• Filament material reference — a built-in database of 15 common materials (PLA/PETG/ABS/ASA/TPU/PA/PC/composites/supports) with recommended nozzle/bed/ chamber temps, drying, plate compatibility, properties, tips and warnings; a "use these temps" action seeds the slice overrides
• Surface-quality overrides — ironing, fuzzy skin, seam position, and adaptive layer height, applied on top of the process profile
• Infill & surface patterns — pick the infill pattern (gyroid, honeycomb, cubic, concentric, …) and the top/bottom solid-surface pattern
• Per-feature speeds — separate infill and solid-infill speed overrides
• Support interface tuning — top gap, interface layers and spacing for supports that peel off cleanly; plus a first-layer-height override
• Per-feature weight/cost breakdown — model vs support vs brim/skirt grams (and cost when a filament price is set) on the slice result
• Prime / wipe tower — multi-material purge tower (width, brim, prime volume, rotation, extra spacing); the controls appear only when >1 filament is selected
• G-code checks — the sliced G-code is linted automatically (13 rules: homing, temp bounds, cold extrusion, Z-hop, retraction, firmware mismatch, …); errors/warnings show on the slice result before you send to the printer
• STL printability — the mesh-health panel reports overhang, a bridge count and a best-orientation tip ("rotate 90° about X → overhang 12%")
• Printer model specs — the profile picker shows build volume / nozzle count / heated-chamber for known printer models
• G-code reference lookup — look up any M/G-code in the console to see its description, parameters and firmware notes
• Save G-code beside the model in Nextcloud Files

Print monitor (Moonraker)

• Automatic printer discovery + recents — a "Scan for printers" button in the target-printer picker finds Moonraker printers on the LAN; the picker groups them as Recent (the printers you actually use, floated to the top), Configured, and Found on network (one-click add for the session)
• Live capability detection — selecting a printer queries Klipper/Moonraker for its real build volume, extruder count, model and OS, shown as a chip (e.g. "308×308×315 · 1 extruder")
• Live telemetry with camera, multi-series temperature graph + PID tuning
• Bed-mesh heatmap + calibrate (idle-only), print/job queue, mid-print exclude-object
• Filament management (Spoolman + runout sensors, load/unload/purge, plus manual extrude/retract in ±0.1/1/10 mm steps, idle-only)
• Power devices — turn a Moonraker-managed smart plug / PSU relay on/off (blocked while printing); shown when the [power] component is present
• Sensor readouts — chamber/other temperature sensors and filament switch/motion sensor state, shown when such sensors exist
• Cameras — lists the printer's configured webcams when more than one exists
• Update & announcement banners — a firmware/component update-available notice and Moonraker service announcements; admins can trigger an update (Klipper/Moonraker/client/system/all) from the app — heavily guarded (admin-only, refused while printing, explicit confirm, restarts services)
• Moonraker history/statistics with embedded thumbnails, timelapse playback
• Read-only G-code console log with an optional admin-gated command input

All Part B monitoring panels feature-detect from Moonraker /server/info and hide when the corresponding plugin is absent.

Native Nextcloud integration

• Notifications — print complete/failed ring the Nextcloud notification bell
• Activity stream — print started/completed/failed events (with filename, printer and duration) appear in the Activity app
• Dashboard widget — "3D printer status" tile shows the active printer's state, progress, ETA and temps at a glance, with a deep link into the app

Architecture

Browser (Vue 2 + Pinia + Three.js)
   │  same-origin
   ▼
Nextcloud app  (OCA\NcPrint, PHP)
   ├─ SlicerProxyController   ──▶ nc-print-slicer sidecar  :8080   (OWNED)
   ├─ MoonrakerProxyController──▶ Moonraker / Klipper  (read-only allowlist)
   └─ PrinterController        ──▶ Moonraker  (guarded writes)
                                        │
      nc-print-slicer (Ubuntu 24.04 container on nc-print-net):
        Xvfb + Mesa software GL → OrcaSlicer-fork CLI (headless)
        FastAPI adapter :8080 — slice (SSE), profiles, toolpath,
        mesh-analyze, arrange, calibration

The Nextcloud container and the sidecar share the nc-print-net Docker network; PHP reaches the engine by container DNS (http://nc-print-slicer:8080). See docs/ARCHITECTURE.md.

Requirements

Component	Requirement
Nextcloud	28 – 34
PHP	8.1+ (matches your Nextcloud)
Docker	for the nc-print-slicer sidecar (Ubuntu 24.04 base — the engine needs glibc ≥ 2.38)
Slicing engine	3DPrintForge Slicer (OrcaSlicer fork) — staged at build time, not committed to git
Moonraker	Reachable Klipper API (configure in Admin settings, e.g. http://printer.local:7125)
Node.js	18+ (frontend build only)

Quick start

# 1. Stage the engine binary + resources into slicer/ (kept out of git)
make slicer-fetch            # set ENGINE_SRC to your local Orca-fork tree if needed

# 2. Build + run the owned slicing engine sidecar, join cloud_app to its network
make slicer-up

# 3. Build the frontend and deploy the app into the running cloud_app container
make deploy                  # sass + webpack, docker cp, occ upgrade (also ensures the sidecar is up)

# 4. Enable + verify
docker exec -u www-data cloud_app php /var/www/html/occ app:enable nc_print
make gate-preflight          # preflight + phpunit + vitest + build + API gates

See docs/INSTALL.md for a from-scratch install and docs/VERIFY.md for the gate/acceptance matrix.

Configuration

Configure in Settings → NC 3D Print (admin):

Setting	Purpose
Slicer internal URL	Owned sidecar (default http://nc-print-slicer:8080); can point at an external engine for back-compat
Moonraker internal URL	Klipper/Moonraker API
Camera snapshot URL	Live camera for PiP / Print monitor
Printer display name	UI label
Allowed groups	Comma-separated Nextcloud groups gate
Multi-printer config	JSON array for multiple printers (with a Discover printers button that scans the LAN for Moonraker instances)
Slicer / Moonraker enabled	Independent feature toggles

The G-code console send input is off by default and, for safety, is not exposed in the admin UI — it is enabled deliberately via occ only (see Security). Docker networking, the sidecar, and its tuning knobs are documented in docs/ADMIN.md.

Security model

NC 3D Print is designed so that no browser can push arbitrary G-code at your printer, and the slicing engine — which parses untrusted uploaded meshes — runs sandboxed:

• The Moonraker proxy is a strict read-only allowlist; raw printer/gcode/script passthrough is blocked. Every write (temperature, tuning, bed-mesh calibrate, filament load/unload/purge, exclude-object, PID) goes through guarded PrinterController actions with parameter validation and idle/motion guards (motion refused while printing).
• The G-code console command input is disabled by default and can only be enabled via occ (console_enabled), not the admin UI; commands are length/charset validated and motion is refused during a print. The response log is read-only.
• The slicing sidecar is internal-only (no host port published; reachable only from cloud_app on nc-print-net), runs with cap_drop: ALL, no-new-privileges, a read-only root filesystem + tmpfs scratch, and memory/PID caps. Uploads over MAX_MESH_TRIANGLES are rejected, slices are concurrency-limited, and job scratch is garbage-collected.
• Slicer/Moonraker URLs are admin-configured only — user paths cannot retarget upstream hosts. App access is gated to the configured Nextcloud groups.

More detail in SECURITY.md.

Development & testing

npm ci
npm run dev            # webpack watch
npm run test           # vitest (frontend unit tests)
make run-phpunit       # PHPUnit (host PHP, or php:8.2-cli container)
make slicer-test       # sidecar adapter unit tests (STL→3MF, overrides, toolpath, calibration)
make gate-preflight    # full gate: preflight + phpunit + vitest + build + API gates

# sidecar end-to-end smoke test (STL → gcode through the adapter)
docker exec nc-print-slicer python3 /opt/adapter/smoke_test.py

CI/acceptance gates are enforced by tools/print-api-gates.php. Changelog: CHANGELOG.md.

Licensing note (AGPL)

The slicing engine is a fork of OrcaSlicer (AGPL-3.0); this app is AGPL-3.0-or-later, so the licences are compatible. The engine binary + resources (~380 MB) are staged at build time and kept out of this repository; the image bakes the engine's LICENSE.txt. If you distribute the built image you must also offer the corresponding source of the engine fork.

Documentation

Doc	Contents
docs/INSTALL.md	Install, sidecar setup & enable
docs/ADMIN.md	Admin config, Docker networking, sidecar tuning, console toggle
docs/ARCHITECTURE.md	Component & sidecar overview
docs/STACK_MAP.md	Lab paths, Forge vs NC Print, health commands
docs/VERIFY.md	Gate & acceptance matrix
docs/LIMITATIONS.md	Known limitations
docs/TROUBLESHOOTING.md	Common issues
slicer/README.md	The owned slicing engine sidecar

License

AGPL-3.0-or-later.