YAMMU

YAMMU is an open, Voron-inspired multi-material unit for FFF printers. It combines eight filament paths, enclosed heated storage, BLDC-driven loading, filament sensing, custom electronics, and Klipper-based control in one machine.

Important

YAMMU is a work in progress. The current goal is reliable loading and unloading before or at the start of a print. Multi-color and multi-material printing are planned, but are not the present focus.

See the machine

Complete enclosure	Twin spool carrier	Heated chamber	Custom electronics bay

One system, four jobs

• Store — eight spools live in two enclosed drawers built around 2020 extrusion.
• Dry — the sealed filament chamber is heated for dry storage while printing.
• Move — two BLDC-driven feeders load filament through short inlet paths and toward the extruder.
• Verify — switches at the splitter and toolhead let the control system confirm filament progress.

Built as open hardware

The repository contains the mechanical, electrical, firmware, and assembly material needed to follow the project—not just product renders.

Area	What is included	Start here
Mechanical	STEP assembly, printable STLs, and panel DXFs	CAD · STLs · DXFs
Electronics	Main, connector, and sensor-board source and manufacturing files	PCB files - new version soon!
Firmware	RP2040 build notes and YAMMU configuration for Klipper / Happy Hare	Firmware guide - new version soon!
Assembly	Illustrated assembly manual	Open the PDF

Start exploring

1. Inspect the STEP assembly or browse the ready-to-print STLs.
2. Read the assembly manual to understand the current mechanical build.
3. (unfinished) Review the PCB feature set and manufacturing files.
4. (unfinished) Follow the firmware guide for the current RP2040, Klipper, and Happy Hare setup.

Current roadmap

View v1.0 progress View v1.1 progress

Help build YAMMU

The project especially needs help with prototype testing, CAD, electronics, firmware, and documentation. If you can test the current iteration or improve one part of the system, open an issue or pull request—or join the YAMMU Discord.

Credits and related projects

YAMMU builds on ideas and parts from the wider open-source 3D-printing community, including Voron Trident, ERCF v2, and several community designs documented in the repository history. Review source licenses before redistributing derived parts.

Third-party parts and original licenses

• Voron Trident parts — GNU GPL v3
• ERCF v2 parts — GNU GPL v3
• Stronger Compact Spool Auto-Rewinder by rans_1668459 — GNU GPL v2
• Voron 2.4 front panel handle, hinge, and magnet latch by Jason_116929 — CC BY-SA
• Removable panel/door kit for Voron V2/Trident by Victor Mateus Oliveira — GNU GPL v3
• WAGO 221-415 extrusion mount by Artxime — GNU GPL v3
• LRS-200 DIN rail mount by CrazyIvan359 — Creative Commons 4.0

Other MMU projects worth exploring include ERCF v2, 8-Track, Primitive Infinite Spool System, TradRack, and Prusa MMU3.

License

Repository content is provided under the GNU General Public License v3.0. Third-party parts retain their original licenses.