DIY Combination Safe – Fully 3D Printable, No Screws

DIY Combination Safe – Fully 3D Printable, No Screws

Build your own mini combination safe with a fully 3D-printable mechanical locking mechanism!

This design features a 3-wheel combination lock that opens only when the correct code is entered. All components are printed in 3D, with no screws, springs, electronics, or additional hardware required.

Features

3-digit mechanical combination lock

Fully 3D-printable design

No screws or external components required

Customizable combination code

Designed for PETG filament

Compact dimensions: 120 × 80 × 60 mm

STL files pre-oriented for easy printing without supports

Reusable mechanical design with a functional locking mechanism

How It Works

Each combination wheel consists of two printed parts: a numbered ring and an internal core. When the correct code is entered, the three internal flats align, allowing the lid's locking teeth to pass through and the safe to open.

The initial combination is 000. You can change the code by disassembling the wheels and reassembling them with your preferred numbers.

Included STL Files

Caja_Cuerpo.stl – Main body

Tapa.stl – Lid with integrated locking teeth

Rueda_Anillo_x3.stl – Three numbered wheel rings

Rueda_Nucleo_x3.stl – Three internal wheel cores

Eje.stl – Wheel axle

Prueba_Tolerancias_*.stl – Tolerance test pieces

Printing Recommendations

Material: PETG recommended

Supports: Not required with the provided orientations

Assembly: Required

Additional hardware: None

Print the tolerance test first to check that the moving parts fit correctly with your printer and material. Adjustments may be necessary depending on your printer's calibration and filament settings.

Important Notes

This is a mechanical 3D-printing project intended for experimentation, organization, and storing small personal items. It is not a certified security safe and should not be relied upon to protect valuable items.

Digital STL files only. No physical product will be shipped.

Print it, assemble it, set your own combination, and enjoy your DIY mechanical safe!