SCABBARD

FI-111 :: board-fitted enclosure generator

A sheath fitted to a blade. Point SCABBARD at a board and it generates a printable 3D enclosure sized to that board, with mounting bosses, auto-placed connector cutouts, a choice of lid, cooling, and text. One HTML file, runs from disk, no server.

License: GPL-3.0

SCABBARD is the STL-out, 3D-printed sibling of COOPER (FI-093, laser-cut finger-joint boxes). COOPER cuts flat sheet into a box. SCABBARD prints a solid case wrapped around a named board.

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Run it

Double-click index.html. That is the whole install. It works offline straight from file://, no build step, no localhost, no dependencies. Everything (geometry, STL export, the isometric preview) is hand-rolled in the one file.

What it makes

• Base: a shelled box sized from the board's footprint and stack height, with mounting bosses on the real hole coordinates, chamfered bottom, recessed feet for stick-on bumpers, and connector cutouts on the walls.
• Lid: snap-fit tongue, friction tongue, or screw-down corners. Screw-down adds matching corner posts in the base with self-tap pilot bores. Optional raised or embossed lid text, an LED window, and a lid-mounted fan (opening plus mounting holes at the standard pitch for the fan size).
• Wall text: a raised legend on the outside of any wall.
• Case mounting: flange tabs on two opposite walls with a plain hole or a keyhole (hang it on two screws), a printed DIN-rail cradle (TS35) that clips on with a slight flex or a sprung thin-lipped latch, and a VESA backplate with a 75mm or 100mm bolt pattern.
• Cable entry: round holes sized for standard cable glands (PG7/PG9/PG11/PG13.5, M12/M16/M20), each with an optional zip-tie strain-relief saddle just inside the wall.
• Display / lid window: a rectangular or round cutout in the lid for an OLED, an LCD, or an LED matrix, positioned from the lid centre.
• Lid recess pocket: a blind rectangular recess milled into the lid top with the boolean CSG engine, for an inset label plaque or a flush display bezel. Drop raised text into it for an engraved-plaque look.
• Gasket groove and bead: an optional O-ring channel recessed into the base rim, with a matching bead on the lid underside that seats into it. Needs a thicker wall so solid lips remain either side of the channel.

Under the hood there is a hand-rolled boolean CSG engine (subtract / union / intersect, with a T-junction healing pass so results are watertight and manifold), used where it produces clean geometry.

• Fit-test coupon: a small clearance ladder and a self-tap boss so you can dial in your printer's real tolerance before committing to the full case.

Export each part as a binary STL, or export the base and lid together as a 3MF where each is a separate object the slicer can arrange. Save the whole configuration as a .case project file and re-open it later.

Boards

Arduino Uno R4 (Minima / WiFi), Arduino Uno Q, the Arduino MKR line, Arduino Giga R1 WiFi, Arduino Giga R1 with the Display Shield, Raspberry Pi 4, Raspberry Pi 5, ESP32 DevKit (30-pin), Raspberry Pi Zero 2 W, Adafruit Feather, Arduino Nano, Raspberry Pi Pico / Pico 2 (W), Teensy 4.1, ST Nucleo-64, and a fully parametric generic project box.

The Giga Display Shield option carries a taller interior for the stacked shield and a display-window preset; use the Board preset button under Lid window, then size the window to your panel.

Measure your own board. Pick the generic box, type in your board's width, depth, PCB thickness, and standoff, then add your own mounting holes and port cutouts. The whole custom board is saved in the .case project so you can reuse it.

Board dimensions and connector positions are typical starting points. Verify against the official mechanical drawing before your first real print. The connector panel lets you toggle each port and edit its offset along the wall, height above the PCB, and cutout size, so you can measure your own board and dial each cutout in exactly; the values save with the project. If a cutout does not fit the wall, or two cutouts overlap, SCABBARD drops the offending one and tells you in the warnings strip rather than emitting broken geometry. This is COOPER's lesson carried over: block, do not corrupt.

Height and fit

The interior height is sized from the board's standoff, PCB, and header stack, and is raised automatically to clear the tallest connector so a stacked USB or Ethernet jack is never guillotined by the rim. Use Headroom for a shield, HAT, or a tall cooler, and Extra stack for anything the board data does not already know about.

Self-test

The Self-test button in the header runs the core geometry assertions on demand: every board, both lid styles, per-body manifold and watertightness, and an STL binary round-trip. Green means the meshes are closed, consistently wound, and positive volume. The same assertions run headless in the Node harnesses (test.js, test-model.js).

Themes and access

Night (default), Light, and High Contrast, all aiming at WCAG AA for body text. Fully keyboard operable with visible focus outlines, ~44px touch targets, and reduced-motion honored. The preview rotates by drag and zooms by wheel.

Conventions

Single file, no build step, disk-runnable. Version marker after the DOCTYPE. In-app About panel with license, credits, and feedback. Debug log behind an in-app toggle. Each release saved as its own file. GPL-3.0.

Known Limitations

• Board data is nominal. Dimensions and connector positions are typical values, not measured from every revision. Print the fit-test coupon and check a dry fit before a full run. Verify against the mechanical drawing.
• Text is single-stroke. The legend uses a simple vector stroke font sized for legibility at FDM resolution, not a full outline typeface. Keep strings short.
• Wall text is raised only. A raised legend sits proud of the wall as its own body. Recessed wall text needs a true pocket, and the CSG engine does not yet cut overlapping glyph strokes cleanly (see below), so wall text stays raised.
• The CSG engine has a robustness boundary. SCABBARD carries a hand-rolled boolean engine, healed to be watertight and manifold, but hand-rolled BSP CSG is only reliable for a single subtraction of a simple, non-self-intersecting cutter. That covers the lid recess pocket cleanly. It does NOT reliably cut text: glyph strokes overlap, and unioning them either leaves non-manifold seams or blows up. So true per-glyph engraved text is not shipped; use a recess pocket with raised text for an engraved-plaque look. Every boolean result is validated and the feature falls back rather than emitting a bad mesh. Round recess pockets are not offered yet for the same reason (curved-cutter T-junctions); use a round lid window for a through-hole.
• DIN and sprung latch are printed clips, not sprung metal. The sprung latch uses thin flexing lips with a snap lead-in. Print in PETG or ABS for give and tune with the coupon.
• Gasket needs wall to spare. The channel and its lid bead are built by construction and need solid lips either side. On a thin wall they are skipped with a warning.
• Vent auto-layout routes around the exit slot, not every connector. Vents will move to the clear side of a GPIO exit slot on the same wall, and the count shrinks to fit. A vent that still lands on a connector cutout is dropped with a warning rather than merged. Full connector-aware nesting is future work.
• STL and 3MF, no STEP. 3MF carries units and separate objects; STL does not, so if you export STL confirm your slicer imports in millimetres.
• Fan fit is enforced. A wall fan that will not fit a short wall, or a lid fan whose mounting pattern would fall off the lid, is left off with a warning. Put a big fan on a bigger case.
• DIN cradle is a fixed clip, not a sprung one. It grips the rail by a slight flex of the printed hooks, so print it in PETG or ABS for give and tune the fit with the coupon. A true spring latch is future work.
• Cable glands are plain sized holes. The hole matches the gland's thread diameter; it does not model threads. The gland's own nut clamps it. The strain-relief saddle is a fixed printed arch you thread a zip tie through, not a sprung clamp.
• VESA plate extends the footprint. If the box is smaller than the bolt pattern, the backplate grows to fit the pattern plus a margin, so it will stick out past the walls.
• Lid window is rectangular or round. One window per lid, no rounded-rectangle or arbitrary display bezel yet. Position and size are yours to set.
• Custom board entry is by prompt. Measure-your-own uses simple prompts for each port and hole. It is functional and saves into the project, but there is no drag-on-canvas placement yet.
• Not a slicer. Wall thickness, bosses, and clearances are print-aware, but supports, infill, orientation, and material are your slicer's job.
• PWA layer deferred. Disk-first only. A service worker cannot register from file://, so offline caching is a later, additive concern, never load-bearing.

Files

• index.html : the instrument. This is the release.
• engine.js : the geometry engine, embedded into index.html at build. Kept separate for the Node test harnesses.
• test.js, test-model.js, test-v11.js, test-v12.js, test-v13.js, test-v2.js : Node assertion harnesses. Run each with node <file>. test-v2.js covers the CSG engine, the lid recess pocket, the gasket bead, and the sprung DIN latch.

Make. Hack. Learn. Share. Repeat.