kidsbox/enclosure/README.md

Kidsbox — 3D-printable enclosure

A parametric, fully 3D-printable reimagining of the original wooden Kidsbox. The design keeps the look of the hand-built box — a rectangular cabinet with two front-firing speakers and a removable top where the NFC tag rests — but makes the speaker mount swappable so you can print an adapter to fit whatever drivers you have on hand.

Modelled in OpenSCAD. Everything is driven by params.scad — change a few numbers, re-export, and print.

---

What's in the box

Part	Qty	File	Notes
Body / cabinet	1	stl/body.stl	Shell with all internal mounts
Lid	1	stl/lid.stl	Buttons + NFC reader mount underneath
Speaker adapter	2	stl/speaker_adapter.stl	Swappable — print to fit your driver
Speaker grill	2	stl/grill.stl	Snaps into the sound opening

The body carries mounts for everything else:

• 2× 18650 battery holder — open-top cradle with retaining lips (batt_* params)
• ESP32-LyraT v4.3 — four floor standoffs (lyrat_* params)
• RC522 NFC reader — pocket on the lid underside, so a tag placed on top reads through the thin (lid_t = 2.4 mm) PLA window
• 3 buttons (vol−, play/pause, vol+) — 12 mm holes in a row near the lid's front edge
• Speaker interface — a fixed bolt pattern the swappable adapters mount to
• Side ports — USB/charging cutout and a power-switch hole
• Vents on the back wall

Body	Lid (underside)

---

Printing

Setting	Recommendation
Material	PLA or PETG (PLA is fine; keep metal away from the NFC window)
Layer height	0.2 mm
Walls / perimeters	3+
Infill	15–20 %
Supports	Body: none (print open-side up). Lid: none. Adapter/Grill: none.
Orientation	Body open-top up; lid top-face down; adapter & grill flat

The body is ~190 × 115 × 110 mm, so it fits a 220 × 220 bed (Ender-3 class) and larger.

---

Assembly

1. Speakers → bolt each driver to a speaker_adapter using the adapter's inner screw holes, then bolt the adapter to the four bosses inside the front wall (M3).
2. Grills → press a grill into each sound opening from the front.
3. Electronics → screw the ESP32-LyraT onto the floor standoffs; drop the 18650 holder into the cradle; route the USB/charge lead to the side cutout.
4. NFC reader → screw the RC522 to the four posts under the lid.
5. Buttons → fit the three 12 mm momentary switches into the lid holes.
6. Close up → lower the lid (the lip locates it) and drive four M3 screws into the corner bosses.

---

Swapping speakers (the whole point)

The front wall never changes — it has a fixed interface: a spk_sound_d opening and four bosses on a spk_bolt_d circle. Every speaker bolts to the box through an adapter that you print to match your driver. To make a new adapter, edit the adapter block in params.scad:

// ---- swappable speaker ADAPTER (edit for YOUR speaker) ----
spk_frame_d      = 66;   // your speaker's outer frame diameter
spk_cutout_d     = 58;   // cone clearance (a bit less than the cone surround)
spk_screw_count  = 4;    // your speaker's mounting-hole count
spk_screw_bolt_d = 60;   // your speaker's mounting-hole bolt circle

Then re-export just that part:

openscad -D 'part="speaker_adapter"' -o stl/speaker_adapter.stl kidsbox.scad

Leave the spk_sound_d / spk_bolt_d (panel) values alone and your new adapter will drop straight onto the same box.

Speaker adapter (swappable)	Grill

---

Regenerating everything

make stl     # export all STLs into stl/
make img     # render preview PNGs (needs a display, or xvfb on a server)
make all

Or one part at a time:

openscad -D 'part="body"'            -o stl/body.stl            kidsbox.scad
openscad -D 'part="lid"'             -o stl/lid.stl             kidsbox.scad
openscad -D 'part="speaker_adapter"' -o stl/speaker_adapter.stl kidsbox.scad
openscad -D 'part="grill"'           -o stl/grill.stl           kidsbox.scad

---

⚠️ Verify before mass-printing

These dimensions are sensible defaults derived from the reference photos and common parts, not from calipers on your exact hardware. Before printing the whole set, print a quick test of the fit-critical features and confirm against your parts:

• ESP32-LyraT mounting-hole rectangle (lyrat_hole_dx, lyrat_hole_dy)
• RC522 mounting-hole rectangle (bx, by in the rc522_mount() module)
• Your 18650 holder footprint (batt_holder_*)
• Speaker frame/cone/bolt-circle (spk_frame_d, spk_cutout_d, spk_screw_bolt_d)

A cheap way to validate the speaker fit is to print one speaker_adapter first.

---

Files

enclosure/
├── kidsbox.scad        master model + part dispatcher
├── params.scad         all tunable dimensions  ← edit here
├── lib.scad            helper modules
├── Makefile            export/render targets
├── stl/                exported STLs
└── img/                rendered previews