OpenCAL brings – OpenCAL expands computed axial lithographic 3D printing with full documentation and a GitHub repository, making it far easier for people to build and run a projector-based CAL setup that uses a spinning vat and FormLabs-assisted resin mixing.
The most eye-catching part of the OpenCAL project is the moment the object appears—because this isn’t a slow. layer-by-layer build on a desktop. It’s computed axial lithographic printing: a machine spins a vat of photopolymer resin while a projector exposes the material. and the printed part shows up fast enough to feel like science fiction.
OpenCAL is pushing that fantasy closer to reality by opening the project up with documentation complete enough to replicate the system. The team has put everything on GitHub, including build guidance, along with instructions for mixing the special resin used in the process.
This effort traces back to the same Berkeley research that came up last year. Back then, the invitation was essentially a Discord server—something that left many people unimpressed with the “open” label. Now. the project keeps the community element. too: there’s still a corporate-hosted chat server named for a malignant goddess. and you’re still invited. But the shift is clear—there is now actual, searchable documentation, not just a place to talk.
For the hardware. OpenCAL stays true to CAL fundamentals: a spinning vat of specially viscous photopolymer resin and light delivered by a NexiGo Nova Mini projector. Unlike some resin-based approaches, the setup doesn’t involve FEP to worry about. The process is described as continuous—no stops and starts—because the vat keeps spinning. the projector keeps exposing. and a part appears with speed and spatial resolution compared to an older SLA.
The assembly instructions focus on getting the projector-based printer together, and they include guidance for mixing the special resin. The project also places heavy emphasis on safety. with a “Don’t Try This At Home” banner calling out the risks involved. That matters because the team is also spelling out a practical workaround: FormLabs is going to mix the resin for people who can’t do it themselves. The idea is to help limit exposure to toxic ooze. and the project notes that a fume hood is what you’d use for safety.
In one respect. OpenCAL doesn’t reinvent CAL at all—it leans on the same core ingredients: a spinning vat. a projector-based exposure step. and specially prepared resin. What it changes is access. Instead of asking builders to take the leap based on conversation alone. it hands over instructions in a way people can actually follow and search through—while still warning. plainly. that the “cool tech” comes with real-world hazards.
OpenCAL computed axial lithographic CAL 3D printing GitHub NexiGo Nova Mini FormLabs resin mixing photopolymer resin 3D printing documentation SLA comparison
So it’s like a Star Trek printer that just spits out parts? Ok but where do I buy the resin.
I saw something about resin mixing and honestly that’s where it loses me. If they’re saying don’t try at home, then how is this “open” for normal people? Sounds more like a project for people with lab setups.
The article says no FEP to worry about which is good right? But then it’s still a toxic spinning vat situation so… pick a lane lol. Also FormLabs mixing it for you sounds like just pay somebody else.
This is “projector-based” so I’m guessing it’s basically just curing stuff with light, like a fancy aquarium light thing. And the mention of a malignant goddess chat server is weird, like why is that even relevant to printing? I don’t trust anything that starts with a Discord invite.