Custom enclosures and parametric design

A custom enclosure is designed from the parts outward — the same inside-out rule from BWF1, now with real numbers. The parts define the space; the shell follows.

What sets the dimensions:

• the PCB footprint — length and width of the board,
• the tallest component — sets the internal height,
• the battery — often the biggest single item to house,
• the connector positions — where the USB, buttons, and screen must break the surface.

Each zone of the enclosure is sized from the biggest thing it has to clear — so the case is never guessed, it's derived.

The best way to feed Forge those numbers is to hand it the real parts:

• Upload a PCB file (.kicad_pcb or .step) and it places connector cutouts exactly where your board's connectors sit (STEP even carries real component heights).
• Upload a datasheet for a specific part and it reads the measured body and mounting holes, then mounts it on proper standoffs.

Give it the parts, and the geometry stops being approximate.

Once the size is right, a handful of details decide whether the case actually works:

• Wall thickness — thick enough to be strong (around 2 mm is a common floor), thicker for parts that take stress.
• Clearance — a small, deliberate gap around every part and at every joint. Real parts and prints aren't exact; zero clearance won't assemble.
• Mounting — standoffs/bosses to hold the board so it doesn't float or rattle.
• Openings — cutouts aligned precisely to the connectors, buttons, and screen (this is why the PCB upload matters).
• A way in — two shells joined by screws or snap clips, so the product can be opened and serviced.

Forge handles the geometry, but you set the intent: tell it what must poke out, what must be reachable, and how it should come apart. The clearer the parts and the openings you describe, the closer the first model is to something you could print and close up.

Design a fitted case for a specific set of parts and see the inside-out method at work.

Send the prompt — a case for an ESP32 board with an OLED on the lid, a side USB-C opening, and an internal LiPo. Generate it, then check the preview against those parts: the case is sized around the board, battery, and connector, not guessed.

If a cutout looks off, don't worry — the next lesson is exactly how you fix it, by refining. (Have a real board? Upload its PCB file in the workspace for exact cutouts.)