The basic idea
Open source hardware means a physical product whose design is published so that other people can study it, change it, make it and often sell it. The design might be a circuit board, a 3D-printable part, a woodworking plan or an entire machine. “Open” refers to the design information, not to whether the product is cheap or easy to build.
The idea comes from open source software, where the source code is shared under terms that let others use and change it. In hardware, the thing that corresponds to source code is the set of files and documents needed to reproduce the product.
This is general information, not legal advice. Rules on copyright, patents and trademarks vary by place.
What an open design usually includes
For a design to be useful to others, the shared material typically includes:
- Design files in an editable format, not only a picture or a locked export. For electronics, that means schematics and board layouts; for printed parts, editable CAD modeling files as well as the model exports; for woodwork, dimensioned drawings.
- A parts list with enough detail to source the components.
- Assembly and testing notes, in the spirit of good build documentation.
- Any code or firmware the product needs, shared under a suitable software license.
- A license statement saying what others may do.
If a project shows only photos and says “open”, or shares only the finished model file with no way to edit it, it is open in name more than in practice.
How hardware differs from software
Copies cost real money and materials. Software can be copied for almost nothing. Hardware has to be built, which takes parts, tools, time and sometimes factory runs. Someone has to pay for that, so “free” in hardware seldom means free to make.
Copyright covers less. Copyright generally protects creative expression such as drawings, text and code. It often protects a useful object less directly. This is why some licenses are written with hardware in mind, and why the choice of design licenses deserves attention.
Patents and trademarks matter. An open license does not usually cancel anyone’s patent rights, and a product’s name and logo are often protected separately. Many open projects allow you to copy and sell the design but not to use the original project’s name as if your copy were the original. If this matters to you, read the intellectual property basics and the project’s own policy.
Physical products carry safety duties. Software failures are usually inconvenient. A badly built charger, heater or toy can start fires or injure people. If you sell a product based on an open design, you may take on responsibility for it, including product safety and labeling rules that differ by place. Never assume the original authors’ design has been tested to the standards that apply where you live.
Components are not always open. A board may be open while its key chips are proprietary parts with their own datasheets and terms. Open does not mean every part inside can be freely reproduced.
Reproducing it takes skill. A design that a skilled person can build may be hard for a beginner. Quality documentation, and teaching it in places like a beginner workshop, makes a design genuinely open in practice.
The usual freedoms
Different groups describe open hardware in slightly different words, but the common thread is that anyone should be able to:
- Study how the product works from its files.
- Make copies.
- Modify the design.
- Distribute the original or modified versions.
- Use the product for any purpose, including selling it.
Some licenses add conditions, such as crediting the original authors or sharing changes under the same terms. A design that forbids commercial use is shared, but many people would not call it open in the strict sense, because that restriction limits the freedoms above.
Why people share designs openly
People publish open designs for several reasons: to help others learn, to get improvements and bug reports, to build a community around a tool, or to encourage repair and reuse. An open design can make repairable design easier, because owners have the information they need to fix the product. It can also allow people to adapt a tool to a need that no manufacturer would address, as in some accessible design projects.
There are trade-offs. Openness makes copying easy, so someone else may sell a cheaper version. Supporting users takes time. Some creators are comfortable with this; others choose different terms. Neither is wrong, as long as the terms are clear.
Checking an open design before you build
Before you make or sell something based on an open design:
- Read the license text and note any conditions on credit, name use and sharing changes.
- Check that the files are complete and editable, and look for notes from people who have built it.
- Confirm which parts of the project are covered by which license, because code, documentation and hardware files may differ.
- Treat safety claims cautiously. If the design involves mains power, batteries, heat or anything that could hurt someone, have it reviewed by a qualified professional before you rely on it.
- If you plan to sell it, look into liability, labeling and any certification rules that apply where you are.
If you want to open your own design
Document as you build, pick a license before you publish, and say clearly what you have and have not tested. Publishing editable files rather than only exports is the step that most improves how useful your design is to others.