Amalgam
A 2026 RepRap Reference Specification
"A Tractor with the Brain of a Racecar"
A scavenger-friendly 3D printer built from two donor printers and open-source intelligence.
Documentation
Build Guides
Print settings, frame assembly, Klipper configuration, calibration, and maintenance. Guides that reference configuration values use the reference spec defaults (220mm bed, Scaffold path, Triple-Z).
Architecture Decision Records
30+ ADRs documenting every major engineering decision — frame paths, motion systems, electronics, extruder, hotend, bed size, and more. Start with ADR-000: Engineering Philosophy.
Reference
- Donor Printer Guide — which printers to scavenge and how they map to frame paths
- Master Parts List — complete BOM for all frame paths
- Parts Sourcing Guide — where to buy what you can’t scavenge
Engineering
- Engineering Analysis — rod sag, acceleration limits, Z-height trade-offs, motion system comparison
- Deep Dives — historical design explorations that informed the ADRs
Articles
Long-form essays on 3D printing philosophy, market dynamics, and open-source heritage.
Frame Paths
Amalgam supports three frame/motion configurations based on your donor printers:
| Path | Frame | Motion | Best Donors | Total Cost |
|---|---|---|---|---|
| Scaffold | M10 Threaded Rod + MDF | Smooth Rods + LM8UU | Anet A8, Wanhao, Prusa clones | ~$190-230 |
| Mill | Aluminum Extrusion + MDF | V-Slots + POM Wheels | Ender 3, CR-10, Voxelab Aquila | ~$160-185 |
| Lathe | Aluminum Extrusion + MDF | Smooth Rods + IGUS | Mixed donors, Ender + bought rods | ~$235-280 |
All paths share an MDF base, Triple-Z leveling, Pitan extruder + E3D V6 hotend, and Klipper firmware.
The Philosophy
Amalgam is not designed to compete with consumer printers. It’s designed to teach you everything about 3D printers by building one from salvaged parts.
Key Principles:
- Scavenge First — Donor printers provide motors, beds, and boards
- Print Your Printer — Most structural parts are 3D printed
- Understand Everything — No black boxes, no magic firmware
- Quality Over Speed — 70-120mm/s with Klipper Input Shaping produces excellent prints
Got one donor? Just add Klipper to it. Amalgam requires two donors minimum.
Want to buy new? Just buy a Bambu A1 Mini. This project is for scavengers.
Getting Started
- Read the Engineering Philosophy to understand the design principles
- Check the Donor Printer Guide to see what your donors provide
- Read ADR-025: Multi-Frame Architecture to understand the frame paths
- Browse the Build Guides for assembly and configuration instructions
For a personalized build with your specific configuration:
python scripts/wizard.py # generate config.py
python scripts/export_config.py > docs/_variables.yml # export for docs
python scripts/analyze.py --quick # engineering analysisGNU GPL v3 — Standing on the shoulders of RepRap Darwin (2007).