AC/DC Socket Plug — EU Child-Safety Blanker

A child-safety blanking disc for EU **Schuko** / **CEE 7/3**

(grounded) and **CEE 7/4** wall sockets. Drops into the round

recess and blocks both phase pin holes — kids can't push hairpins,

forks, or fingers into the live contacts.

## Design

- **Ø 38 mm round disc** with a domed back face: 14 mm tall at the

  rim, rising to 19 mm at the centre. The dome is the visible side

  once seated.

- **Two large spherical finger pockets** carved into the dome and

  pushed out toward the rim — Ø ~18 mm bowls that bite ~3 mm into

  the cylinder side wall for thumb-and-finger grip leverage. Pulling

  the plug back out one-handed is easy.

- **U-shaped earth-pin slot** opens through one edge of the disc rim

  so the plug seats fully even on **grounded (CEE 7/3 / Schuko)**

  sockets where the earth pin sticks up from the recess wall.

- **Lightning-bolt logo** recessed into the dome surface as a 2-colour

  AMS inlay. Pure decoration — the plug works the same single-colour.

## What you print

Two-colour print via a coordinate-locked combined STL:

- `socket_plug_acdc.stl` — ASCII multi-solid (body + logo) for Bambu

  Studio's *Split to Parts*. **Recommended.**

- `body.stl` — filament A (dark dome) — single-colour fallback if

  you don't have AMS, the bolt becomes a recess rather than a colour

  inlay (still visible, just monochrome).

- `logo.stl` — filament B (yellow bolt) — drop into the body's

  recess if printing parts separately.

## Bambu AMS workflow (recommended)

1. **Import** `socket_plug_acdc.stl` into Bambu Studio.

2. **Right-click** the imported object → *Split to Parts*.

3. Two sub-parts named `body` and `logo` appear, locked at exact

   coordinates.

4. Assign **filament A (dark / structural)** to `body` — black, dark

   grey, or anthracite contrast best with the yellow bolt.

5. Assign **filament B (accent)** to `logo` — bright yellow, gold,

   or copper. The pictured pair is white body + yellow bolt.

6. Slice. Print **front face DOWN on the bed** (= dome up). Finger

   pockets become concave bowls opening upward, no supports anywhere.

## Print settings

- Bambu Lab P2S (or any 0.4 mm FDM)

- 0.2 mm layer height, 3 walls, 15 % infill

- PLA Basic

- **No supports**

- Print **front face DOWN** (dome up)

- ~12 g per plug, ~30 min print time

## Fitment

Designed for the European **Schuko** family (the round 38–40 mm

recess with two phase-pin holes and a vertical earth-pin slot at the

top of the recess wall). Confirmed fit: Czech / German / Austrian /

Dutch / Belgian wall sockets.

**Won't fit**: UK BS 1363 (rectangular pin pattern), Swiss SEV 1011

(triangular), Italian CEI 23-50 (linear three-pin), or any North

American socket. Different geometry entirely.

## Source

Full parametric `.scad` is included. Variables at the top of the file

control:

- Plug diameter, rim height, dome apex height

- Finger pocket Ø, position, depth

- Earth-pin slot width / inner-end position

- Lightning-bolt size, position, recess depth

If your socket recess is slightly tighter or looser, bump `plug_d`

by a few tenths of a mm and re-render.

## Safety note

This is a **passive blanker** — it doesn't replace certified

child-safety shutters or RCDs, and it has no electrical insulation

rating. PLA is non-conductive but a 3D-printed part is not a

certified electrical safety device. Use it as one layer of

defence against curious toddler fingers, alongside socket shutters

and proper supervision.