enclosure-designer（外壳设计师）

Enclosure Designer

Creates 3D-printable enclosures for electronics projects.

Resources

This skill includes bundled tools and templates:

• scripts/generate_enclosure.py - Parametric OpenSCAD generator with PCB database
• assets/basic-template.scad - Customizable OpenSCAD template

Quick Start

Generate for specific PCB:

uv run --no-project scripts/generate_enclosure.py --pcb "Arduino Uno" --output uno_case.scad
uv run --no-project scripts/generate_enclosure.py --pcb "ESP32 DevKit" --output esp32_case.scad

Custom dimensions:

uv run --no-project scripts/generate_enclosure.py --width 100 --depth 60 --height 30 --output custom.scad

Interactive mode:

uv run --no-project scripts/generate_enclosure.py --interactive

List supported PCBs:

uv run --no-project scripts/generate_enclosure.py --list

When to Use

• "I need a case for my project"
• "How do I make an enclosure?"
• "Design a box for my Arduino"
• User has working circuit, needs housing
• Preparing for deployment/presentation

Design Workflow

Step 1: Gather Measurements

Ask user for:

1. Main board dimensions (L × W × H in mm)
2. Component clearances (tallest component height)
3. Connectors/ports that need access (USB, power jack, etc.)
4. Mounting holes (positions, diameters)
5. Any displays, buttons, LEDs that need cutouts
6. Environment (indoor/outdoor, waterproof?)

Step 2: Design Parameters

Enclosure Type: [Box/Clamshell/Snap-fit/Screw-mount]
Material: [PLA/PETG/ABS]
Wall Thickness: [2-3mm typical]
Mounting Style: [Standoffs/Clips/Rails]
Ventilation: [None/Slots/Holes]
Access: [Top-remove/Front-panel/Side-openings]

Step 3: Generate Design

Choose approach:

1. Parametric OpenSCAD - Full customization
2. Pre-made generator - Quick results
3. Manual Fusion360/TinkerCAD - Visual design

Parametric OpenSCAD Template

Basic Project Box

// === PARAMETRIC PROJECT BOX ===
// Customize these values for your project

// Internal dimensions (mm)
inner_length = 70;    // X axis
inner_width = 50;     // Y axis
inner_height = 30;    // Z axis (internal depth)

// Wall and tolerances
wall = 2.5;           // Wall thickness
lid_tolerance = 0.4;  // Gap for lid fit
corner_radius = 3;    // Rounded corners

// Mounting standoffs
standoff_height = 5;  // PCB clearance from bottom
standoff_dia = 6;     // Standoff outer diameter
screw_hole_dia = 2.5; // M2.5 screw hole

// PCB mounting hole positions (from corner)
// Measure from your board!
pcb_holes = [
    [5, 5],           // Bottom-left
    [65, 5],          // Bottom-right
    [5, 45],          // Top-left
    [65, 45]          // Top-right
];

// Lid attachment
lid_screw_dia = 3;    // M3 screws
lid_screw_positions = [
    [5, 5],
    [inner_length-5, 5],
    [5, inner_width-5],
    [inner_length-5, inner_width-5]
];

// Cutouts (add as needed)
usb_cutout = true;
usb_x = 35;           // Center position
usb_width = 12;
usb_height = 8;

// === MODULES ===

module rounded_box(l, w, h, r) {
    hull() {
        for (x = [r, l-r])
            for (y = [r, w-r])
                translate([x, y, 0])
                    cylinder(h=h, r=r, $fn=32);
    }
}

module standoff(h, outer_d, inner_d) {
    difference() {
        cylinder(h=h, d=outer_d, $fn=24);
        cylinder(h=h+1, d=inner_d, $fn=24);
    }
}

module box_base() {
    outer_l = inner_length + 2*wall;
    outer_w = inner_width + 2*wall;
    outer_h = inner_height + wall;  // Bottom wall

    difference() {
        // Outer shell
        rounded_box(outer_l, outer_w, outer_h, corner_radius);

        // Inner cavity
        translate([wall, wall, wall])
            rounded_box(inner_length, inner_width, inner_height+1, corner_radius-wall);

        // USB cutout
        if (usb_cutout) {
            translate([wall + usb_x - usb_width/2, -1, wall + standoff_height])
                cube([usb_width, wall+2, usb_height]);
        }
    }

    // Add standoffs
    for (pos = pcb_holes) {
        translate([wall + pos[0], wall + pos[1], wall])
            standoff(standoff_height, standoff_dia, screw_hole_dia);
    }
}

module box_lid() {
    lid_wall = wall - lid_tolerance;
    outer_l = inner_length + 2*wall;
    outer_w = inner_width + 2*wall;
    lip_h = 5;  // How deep lid inserts

    // Lid top
    rounded_box(outer_l, outer_w, wall, corner_radius);

    // Lid lip (inserts into box)
    translate([wall + lid_tolerance, wall + lid_tolerance, -lip_h])
        difference() {
            rounded_box(inner_length - 2*lid_tolerance,
                       inner_width - 2*lid_tolerance,
                       lip_h, corner_radius - wall);
        }
}

// === RENDER ===

// Uncomment one at a time for printing:
box_base();
// translate([0, inner_width + 20, 0]) box_lid();

Adding Cutouts

// === CUTOUT LIBRARY ===

// Round hole (for buttons, LEDs)
module round_cutout(x, y, z, diameter, depth) {
    translate([x, y, z])
        rotate([90, 0, 0])
            cylinder(h=depth, d=diameter, $fn=32);
}

// Rectangle (for displays, SD cards)
module rect_cutout(x, y, z, width, height, depth) {
    translate([x - width/2, -0.1, z])
        cube([width, depth + 0.2, height]);
}

// Slot (for ventilation, cables)
module slot_cutout(x, y, z, width, height, depth) {
    translate([x, y, z])
        hull() {
            translate([0, 0, 0])
                cylinder(h=depth, d=height, $fn=24);
            translate([width-height, 0, 0])
                cylinder(h=depth, d=height, $fn=24);
        }
}

// OLED display cutout (128x64 module)
module oled_cutout() {
    // Visible area
    rect_cutout(inner_length/2, wall, inner_height - 15, 26, 14, wall+1);
    // Mounting holes (if needed)
}

// Common connector dimensions
usb_micro = [8, 3];      // USB Micro
usb_c = [9, 3.5];        // USB-C
barrel_jack = [12, 12];  // 5.5mm DC jack (round)
sd_card = [15, 3];       // SD card slot

Online Generators (No CAD Needed)

Ultimate Box Maker (Thingiverse)

https://www.thingiverse.com/thing:1264391

Parameters:

• Enter internal dimensions
• Choose wall thickness
• Select lid type (snap/screw/slide)
• Add ventilation slots
• Download STL

Parametric Box by Heartman

https://www.thingiverse.com/thing:1355018

Good for:

• Simple project boxes
• Snap-fit lids
• Basic customization

FreeCAD + Parametric Enclosure

1. Install FreeCAD
2. Use Spreadsheet workbench for parameters
3. Generate enclosure with formulas
4. Export STL

Common Board Dimensions

Arduino Family

ESP32 Family

Raspberry Pi Pico

Common Modules

Design Guidelines

Wall Thickness

Application              Thickness
─────────────────────────────────────
Desktop/indoor           2.0 mm
Portable/handheld        2.5 mm
Outdoor                  3.0 mm
Structural/load-bearing  4.0+ mm

Clearances

Component           Add clearance
─────────────────────────────────────
PCB to wall         1-2 mm
USB/connector       0.5 mm extra per side
Moving parts        2-3 mm
Lid fit             0.3-0.5 mm gap

Mounting Strategies

PCB Standoffs:

    [Standoff]──┐
        │       │
    [PCB]       │ standoff_height
        │       │
    ────────────┘
        ▲
     box_floor

Edge Rails:

    ┌────────────┐
    │    [PCB]   │
    │  ───────   │
    │ /       \  │  <-- Rails support PCB edges
    └───┘   └────┘

Snap-in Clips:

    ┌──╲   ╱──┐
    │   [PCB] │
    │  ───────│
    └─────────┘
        ▲
     Flexible clips

Ventilation

When needed:

• MCU draws >100mA continuously
• Motor drivers
• Power regulators
• Any component getting warm

Vent patterns:

// Slot pattern (easy to print, good flow)
for (i = [0:5]) {
    translate([10 + i*8, wall/2, 10])
        slot_cutout(20, 3, wall+1);
}

// Honeycomb (looks cool, harder to print)
// Use pre-made pattern from Thingiverse

Print Settings

Material Selection

Recommended Settings

PLA Enclosure:

Layer height: 0.2mm
Wall count: 3-4 (for 2-3mm wall)
Infill: 15-20%
Support: Usually not needed if designed right
Bed temp: 60°C
Nozzle temp: 200-210°C

PETG Enclosure:

Layer height: 0.2mm
Wall count: 3-4
Infill: 20-25%
Support: Often needed
Bed temp: 80°C
Nozzle temp: 230-245°C
Print slower than PLA

Orientation Tips

Print box BASE standing up (opening facing up)
- No supports needed
- Good surface finish inside
- Strong walls

Print LID flat (top surface down)
- Smooth exterior surface
- May need supports for cutouts

Waterproofing

IP Rating Guide

IP65 - Dust tight, water jets OK
IP67 - Dust tight, submersible briefly
IP68 - Dust tight, continuous submersion

Strategies

Rubber Gasket:

Add groove in lid for O-ring:
    ┌───╔═══════╗───┐
    │   ║O-ring ║   │
    │   ╚═══════╝   │
    │    [box]      │
    └───────────────┘

Cable Glands:

• Use PG7/PG9 cable glands for wires
• Drill precise holes, thread in glands
• Seal with silicone if needed

Conformal Coating:

• Spray PCB with conformal coat
• Protects electronics inside box

Example: ESP32 Weather Station Enclosure

// ESP32 Weather Station Enclosure
// Components: ESP32 DevKit, BME280, SSD1306 OLED, 18650 battery

// Internal dimensions (measured from components + clearance)
inner_length = 80;
inner_width = 55;
inner_height = 50;  // Room for battery under PCB

wall = 3;  // Outdoor = thicker walls

// ESP32 on standoffs
esp_standoff_h = 25;  // Above battery
esp_holes = [[5, 5], [5, 50], [52, 5], [52, 50]];

// OLED window position (top of enclosure)
oled_x = 40;
oled_y = 15;
oled_w = 28;
oled_h = 16;

// BME280 vent hole
bme_vent_x = 70;
bme_vent_y = 30;
bme_vent_dia = 8;

// USB access
usb_x = 30;
usb_y = inner_height - 15;

// Generate with above parameters...

Troubleshooting

Resources

• OpenSCAD: https://openscad.org
• Thingiverse Customizer: Parametric designs
• Printables: More enclosure designs
• McMaster-Carr: Reference for hardware dimensions