A compact protective case for the Hohner Special 20 diatonic harmonica, designed for durability, portability, and easy printing.

This case consists of two 3D-printable parts (body and lid) that assemble without screws. The hinge uses a simple 50 mm piece of standard 1.75 mm filament as the pin, making assembly quick and tool-free.

The lid closes securely using embedded neodymium magnets, keeping the harmonica protected while allowing fast one-hand opening.

The model is optimized to print without supports and works well on most FDM printers.

Features:

• Designed specifically for Hohner Special 20 harmonicas

• Magnetic closure for secure transport

• Support-free printing

• Tool-free hinge assembly using filament

• Compact and pocket-friendly

• Includes a STEP file for customization

• Variants Included

Two body versions are provided:

• Standard body – clean minimalist design

• Keychain version – includes a 3 mm channel to attach a cord, keyring, or wrist strap

Hardware Required

• 10 × Neodymium magnets

Diameter: 5 mm

Height: 1 mm

• 1 × Filament hinge pin

Length: 50 mm

Diameter: 1.75 mm

Printing Notes:

• Prints without supports

• Recommended layer height: 0.2 mm

• 4 walls recommended for strength

• PLA, PETG or ABS all work well

Files Included:

• Magnetic case body (standard)

• Magnetic case body with keychain channel

• Magnetic case lid

• STEP source file for customization

Compatibility:

Designed for Hohner Special 20 diatonic harmonica

(Other 10-hole harmonicas may fit, depending on dimensions.)

Hope you find it useful!

If you print it, please share a make!

Hohner Special 20 Magnetic Case

0.2mm layer, 4 walls, 15% infill, no supports

0.2mm layer, 2 walls, 15% infill