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.