Today, we are releasing the full CAD files for the CORE One and CORE One L frames. You can download them right now, load them into your CAD software and use them to create mods and accessories, import them to Fusion or Blender to plan your workshop, and do whatever cool hack you can think of!

But if you look at the license, you will notice something different. We aren’t using the standard GNU GPL or Creative Commons license for these files. Instead, we are releasing them under the Open Community License (OCL).

What you can do with these files under OCL

✅ Download, inspect, and learn from the full STEP + Fusion assemblies

✅ Modify them and share your mods (under the same OCL)

✅ Use modified or unmodified designs in your own workshop, print farm, or production line

✅ Produce spare parts to keep your machines running (home or business)

❌ Sell complete machines or remixes based on these files, unless you have a separate agreement with us


Now let’s talk about what the OCL actually is, and why we’re introducing it.

TL;DR: What is the Open Community License

The Open Community License (OCL) is our answer to the gaps left by traditional software licenses when applied to physical hardware.

It is designed to be concise and human-readable (it fits on one page) and it even includes practical examples linked directly in the document so you know exactly what you can and cannot do.

For Makers & Hackers: You have complete freedom to use, modify, and share derivatives back to the community.

For Businesses: You can build and modify machines based on the source designs for your internal production (e.g., a custom print farm). Unlike vague “Non-Commercial” licenses, OCL explicitly allows you to make money using these designs to run your business; you just can’t make money selling the machines.

The Restriction: You cannot commercially exploit the design files (selling the product or remixes) without a separate agreement.

The Protection: It includes an explicit patent license grant, protection against AI data mining, and a codified Right-to-Repair.

Over the last few years, we’ve had to hold some source files because the old licenses simply didn’t protect the work or the people who built on it. OCL is our way to start opening things up again without pretending those problems don’t exist.

Important: OCL applies to intellectual property, not physical products. If you bought a CORE One, it’s yours. Sell it, modify it, do whatever you want. OCL covers the CAD files, designs, and source code you download. The terms above apply to what you create from that IP, not to hardware you already own.

The Open Community License – A Shield for Your Creations

We designed the Open Community License to be a template that any business or creator in the community can use.

We have seen it happen too many times: A talented community member designs a brilliant extruder or hotend mod. A commercial entity sees it, mass-produces it, and sells it without giving a cent (or sometimes even credit) back to the creator.

To make this protection accessible to everyone, we are adding the Open Community License directly to Printables.

You can also download it as plain text and use it on any other platform. The Open Community License has its own organization on GitHub. We expect to iterate and improve the license based on the feedback, and even form an organization around it.

What a License Can and Cannot Do

I read the comments. I know some of you are thinking, “A new license won’t stop a bad actor in a jurisdiction that ignores IP law.”

You are right.

A text file in a GitHub repository or Printables model page is not a force field. It won’t stop bad faith actors who are determined to ignore the rules. But the reality is that prior art is not a shield either. There is a myth that simply publishing something “Open Source” prevents others from patenting it. It surely should but in practice it doesn’t. Proving prior art against spam of foreign patents costs thousands of dollars per case and takes months or years. We know this first hand.

A Real-World Warning: The Case of Lucky 13

This isn’t hypothetical. I wrote a full article about the current landscape of open hardware in desktop 3D printing, including the example of our MMU1 multiplexer (from 2016!) being patented as an exact copy.

It is also happening right now to one of the most popular creators on Printables.

You probably know Soozafone, the creator of the Lucky 13 and Dummy 13 printable figures. These designs are legendary in the community, winning the Printables Awards by a landslide in 2024. Soozafone released his designs under a Creative Commons license.

A foreign entity took the design and filed for a US Design Patent (D1055176) on it. Because the patent office didn’t find the specific prior art during the patent examination, the patent was granted. Now, armed with this illegitimate patent, they are aggressively issuing takedown notices and demanding licensing fees of over $10,000 a year from sellers. Even targeting the original upload on Printables!!! So the original creator now faces legal threats for sharing his own design.

We are funding the legal battle to invalidate these patents. Our in-house patent attorneys have filed a request for reexamination with the USPTO to prove that Soozafone’s design was public long before the patent was filed.

Would OCL have stopped the patent from being granted? The short answer is:  No.

If Soozafone had uploaded Lucky 13 under OCL, the patent examiner likely still would have missed it, and the patent likely still would have been granted. A license file doesn’t magically appear on a patent clerk’s desk in Virginia.

However, the long answer is: It changes the war that comes after. It removes the excuse: A troll cannot claim they “didn’t know” the mechanism was open, because the license explicitly grants patent rights to the user. It also creates even more serious contract violation. By downloading the files, the bad faith actor agrees to the OCL terms. If they then patent the design, they are violating the license agreement, giving creators a second legal weapon:  breach of contract, which is often faster and cheaper to prove than prior art.

We are happy to help Soozafone, but we cannot fight every single case individually. The community needs a stronger shield. By adopting the OCL, we establish a standardized legal framework that asserts your rights from day one.

“Dealing with patent trolls targeting Dummy 13 has been a real headache, but I hope that my story doesn’t discourage my fellow creators from sharing your designs online. Instead, it should remind you that your work is worth something. You should never feel shame about protecting your creative work, because these companies certainly won’t feel any shame about stealing it.

These days, I often feel like Dummy 13 no longer belongs to me. Sometimes this is a good thing: it feels like it belongs to our community of printers and remixers, who have taken it far beyond what I could have created as a solo designer. Other times it’s a very bad thing: like when a company actively harms our community of makers by greedily staking an unfair claim.

OCL will not solve this overnight; I often tell people “a license isn’t a magic spell.” But OCL is one more tool that creators can use to protect ourselves, and one more step towards a future where we can share our work on our own terms, in the community we build together.

I am extremely grateful to Josef and his team, not just for supporting me in my specific fight, but for standing up for all creators who deserve fair credit and compensation for their work.”

– Soozafone, creator of Dummy 13

The Right License for the Right Job

The standard OSI licenses, some established over 30 years ago, remain the gold standard for collaboration. We continue to use them exactly where they make the most sense.

For example, the market for smart spools was a mess of proprietary, vendor-locked RFID tags. That is bad for everyone. So we created OpenPrintTag and released it under the MIT License. Do whatever the hell you want with it. We want competitors to adopt it, because a universal standard is better for the user.

PrusaSlicer stays fully open-source, licensed under GPL. It powers the entire 3D printing industry, and we are proud of that. The firmware for our printers is also licensed under GPL. In both cases, we’ve rewritten so much of the original projects we forked that it wouldn’t be hard to rewrite the rest and close it down. But that would be against everything we stand for.

But we are missing a simple (and I cannot stress this enough) license that would be fully open for non-commercial and still open for internal commercial use. Basically we had to either choose a fully open or copyleft license which removes all control or a non-commercial licence which restricts all business use.

Furthermore, most licenses were source code focused and hardly usable for data (graphical or technical) let alone hardware itself. Based on that we had to mix and match licenses that can sort of live together in one product each for different part. OCL should remove these restrictions. Keep things open, if needed all under the same license, and still keep control to exclude people who don’t play fair.

I like to use the quote “Insanity is doing the same thing over and over again and expecting different results.” The maker community has been stuck with the same impossible choice: share openly and watch your work get exploited, or lock it down and lose what made it valuable in the first place. We’ve been there. We held back files we wanted to share because the old tools failed us. OCL is how we break that cycle, for ourselves and for anyone else who’s been stuck in it.

Why not just use GPL, BSL, CC or patents?

  1. Why not the GPL? The GPL is legendary in software history. But applying its 6,000 words of complex definitions to hardware creates massive confusion. Worse, it forces you to allow commercial exploitation. Imagine spending months perfecting a mechanism and sharing it with the community. A corporation can take it, mass-produce it, and “comply” with the license simply by dumping a messy, undocumented zip file on their website (if they even do that). The letter of the law is satisfied. The spirit of sharing is dead.
  2. Why not the BSL? Some tech companies are switching to the Business Source License (BSL). While BSL allows you to see the files, it usually puts your right to actually use them on a timer. We want you to be able to hack, modify, and share your remixes even for your production purposes today, not in 2029.
  3. Why not CC BY-NC? It is the closest existing standard to what we need. However, CC licenses were designed for photos, text, and music, not for functional designs, manufacturing, and patent law, not to mention how vast it is to read. CC explicitly excludes patent rights, meaning you could technically have the copyright to the file but be sued for the mechanism inside it.

OCL includes an explicit Patent License Grant, creating a safe harbor for everyone using the files legitimately. CC is also legally vague; lawyers can argue that simply using the licensed thing in a business context violates “Non-Commercial” terms. OCL explicitly allows Internal Commercial Use. You can make money using these designs to run your business; you just can’t make money selling the licensed designs.

And then there’s the Right-to-Repair. Under strict interpretations of ‘Non-Commercial’ licenses, even a business producing a spare part to fix their own production machine could be seen as gaining a commercial advantage. OCL explicitly protects your internal Right-to-Repair. Whether you are a hobbyist at home or a business owner, you have the codified right to produce spare parts to keep your machines running, without legal ambiguity.

To ensure we can keep developing machines like this and releasing files under the OCL, we must protect the engineering that makes them possible. We are now actively filing for both utility patents to cover our technical inventions and design patents to protect our unique aesthetics.

We are not interested in filing spam patents. We focus on protecting real, novel engineering, small or large, that pushes the industry forward. For example, we patented a unique cooling system for our HT90. The heavy cooling fan is moved off the printhead and onto the frame, with the air being pushed via a lightweight tube. However, at the end, it uses a servo-driven damper to reroute or close the airflow instantly. So it’s basically a CPAP machine, but with zero latency. Giving you the speed of a lightweight print head with massive cooling power that can start or stop in milliseconds.

We have developed and patented a unique SLA Equalizer system. It uses a camera sensor to map the light intensity of every single pixel of the print LCD, then runs an iterative calibration. It digitally dims the pixels that are too bright and boosts the power for the dark ones. The result is a perfectly homogenized light field across the entire build plate, without hot spots and dim corners. It guarantees that a model printed in the corner cures exactly the same way as one printed in the center.

We are also protecting smaller but crucial quality-of-life improvements, like our new 3-stage nozzle cleaning system we’re currently testing on the AFS.

Building a Coalition

We want to share these technologies with like-minded companies. We are building an alliance where legitimate innovators can cross-license and protect each other, while blocking those who simply extract value without contributing back.

We are happy to license our patents to others who respect the rules of the game. If you contribute to the ecosystem, we will find a way to work together.

The OCL includes an explicit patent license grant, so makers can still mod, hack, and build as they wish. These patents exist to stop industrial clones, not your garage workshop.

Which brings me back to the release of the CORE One CAD files.

Finding a way to release CORE One / L under OCL is our proof that we can protect our work and still share real source without shooting ourselves in the foot. We want to be here in another 10 years, still releasing files and still supporting the community.

An Early Christmas Gift – Go Wild!

I know that for many of you, the upcoming break isn’t about sitting still. It’s the one time of year where you’ll finally have enough free hours to tackle that big project, upgrade your workshop, or design that crazy mod you’ve been thinking about.

So, consider this like an early Christmas present to you. Both the STEP files and a Fusion assembly of the CORE One(+) and CORE One L are live on Printables right now.

Download the files. Read the license. Let us know what you think. And if you believe in what we’re building, use the OCL for your own creations.