3 model

Free

USB Buck Converter Case - Power OctoPi from your Printer Power Supply - Ender 3 - 4040

Thingiverse

Free

LM2596 / LM2596S Buck Converter Case with 2020 Mount and Power Switch

Thingiverse

Free

Anet A8 Electronics Enclosure (Octopi, Relay, Mosfets, and Power Converter Module)

Thingiverse