GNUchair - open-source, repairable chair

The project is still WIP

📖 The Story & Philosophy

The GNUchair is not just a piece of furniture; it is a manifesto on the Right to Repair and the Democratization of Design.

In a market flooded with cheap, unrepairable plastic chairs or overpriced, complex ergonomic machines, the GNUchair offers a third path. It is a workshop chair designed to be built, understood, modified, and repaired by its user. By combining the industrial rigidity of 3060 Aluminum Extrusions with the accessibility of 3D Printing and Plywood, we have created a seating platform that eliminates the need for industrial factories.

If a part breaks, you don't throw the chair away—you print a new one. If you need a different backrest angle, you modify the CAD file. You are not a consumer; you are a maintainer.

✨ Key Features

• 🏭 Industrial Core: Built around standard 3060 T-Slot aluminum profiles, serving as both the structural spine and the linear guide rail.

• 🔧 Zero-CNC Woodworking: All plywood components feature orthogonal, straight-cut geometry. You do not need a CNC router—a simple jigsaw, circular saw, or table saw is enough.

• ⚙ Unique Sliding Mechanism: The height adjustment relies on a custom-designed, 3D-printed friction clamping mechanism that slides directly in the aluminum groove. No gas pistons to fail, no complex hydraulics.

• ♻ 100% Repairable: No glue, no hidden snaps, no proprietary screws. Every connection is bolted and reversible.

• 🧱 Modular Ecosystem: The T-slot profile allows you to easily mount accessories (tool holders, cup holders, camera mounts) directly to your chair.

🛠 Bill of Materials (BOM)

WIP

🖨 Printing Settings

This chair is a functional load-bearing object. Do not use standard PLA.

• Material: PETG or PLA is fine

• Nozzle: 0.4mm or 0.6mm (0.6mm recommended for faster, stronger prints).

• Perimeters (Walls): Minimum 4-5 perimeters. Wall strength is more important than infill.

• Infill: 40% Gyroid (or 3D Honeycomb). Do not use Grid or Rectilinear.

• Layer Height: 0.2mm - 0.3mm.

• Supports: none.

🪚 Fabrication & Assembly Guide

Step 1: The Aluminum Frame

Cut your 3060 profiles to length. Ensure the cuts are square (90°) for the best stability. If you don't have a metal saw, most aluminum suppliers offer cutting services.

Step 2: The Plywood (WIP)

Download the .PDF or .DXF template from the files section.

1. Trace the shapes onto your plywood.

2. Cut using a jigsaw or handsaw.

3. Sand the edges (especially the seat front) for comfort.

4. Drill the mounting holes as indicated in the template.

Step 3: Printing

Print all STLs. Ensure your printer is calibrated for dimensional accuracy, as the parts must fit tightly onto the aluminum profile.

Step 4: Assembly

1. Slide the printed Base Hub onto the bottom profile and secure with T-nuts.

2. Assemble the Slider Mechanism on the vertical profile. Test the lever—it should lock firmly when pushed down and slide freely when pulled up.

3. Bolt the plywood Seat and Backrest to their respective printed mounts.

4. Sit down and adjust the tension if necessary.

🤝 Contribute & Remix

This project is Open Source Hardware.

• Source Files: STEP and Fusion360 files are included.

• Feedback: If you find a weak point, please comment or upload a Remix with a fix.

Disclaimer: This is a DIY project. The creator is not responsible for any injuries caused by assembly errors or material failures. Test your print strength before full use.