A University of California, Berkeley research team has released the build plans for a 3D printer that skips layers entirely, forming a complete resin object inside a spinning vial in roughly one minute. The machine, called OpenCAL, uses a technique known as computed axial lithography, and the team says anyone with a bill of materials running around $1,638 and five to six hours of free time can put one together at home.
How a Spinning Vial Replaces the Print Head
The process works by rotating a vial of liquid resin while a projector fires a fast-changing sequence of calculated light patterns through it, according to OpenCAL's own documentation. The resin hardens only where the projected light adds up inside the volume, meaning the whole object solidifies simultaneously, with no layers and no support structures needed. As 3D Printing Industry reported, an inch-scale part typically takes just one to two minutes to form, and the reference part used in the project's technical paper, a replica of Rodin's Thinker, formed in 90 seconds.
That technical paper, authored by Waddell and colleagues, is publicly posted on arXiv, where it describes OpenCAL as a low-cost platform built from commercial off-the-shelf components and standard rapid-prototyping tools. The paper was first submitted on September 2, 2025, and last revised on October 9, 2025. Taylor Waddell led the project, which according to a report from VoxelMatters took two years and drew more than 40 contributors, most of them Berkeley undergraduate and graduate students.
What It Costs and How Long It Takes to Build
Figures on the exact build cost vary slightly between outlets covering the project. 3D Printing Industry put the parts cost at around $1,600, while VoxelMatters cited a June 2026 bill of materials totaling about $1,638. Either way, once the parts are in hand, VoxelMatters reports that one person can assemble the OpenCAL V2 machine in five to six hours. The V2 design combines a consumer LED projector, a Raspberry Pi 5, a stepper-driven vial mount, an aluminum extrusion frame, and laser-cut acrylic panels, with the whole unit reportedly fitting inside a camera case.
Berkeley's underlying strategy, per the dossier of project materials, is to make computed axial lithography buildable outside research labs by pairing open hardware and software designs with commercial resin and distribution partners. The hardware is released under Prusa's Open Community License, OCL 1.1, giving builders the right to build, modify, repair, and share the design, while the software is licensed by the University of California for educational, research, and non-profit use, with commercial applications requiring a separate agreement through the UC Office of Technology Licensing, according to the project's GitHub repository. Berkeley's own project page similarly notes that OpenCAL materials are free for non-profit, research, and educational use under a GPL3 license, with commercial use handled case by case.
Resin, Software, and Where the Machines Are Already Running
Formlabs now manufactures the dedicated photopolymer resin for OpenCAL, a UDMA-based formulation developed and tested at Berkeley, producing it at production scale in one-liter bottles, VoxelMatters reports. Prusa Research sells that resin in the United States for $119.99 per bottle through its US online store, Printed Solid. On the software side, a free Windows application called Tomo converts an STL file into a print sequence without requiring any coding, built on an open-source Python library called VAMToolbox that handles the tomographic optimization CAL relies on.
The documentation covers wiring diagrams, assembly steps, and washing and curing procedures, and the project's materials page advises always wearing nitrile gloves when handling resin or uncured, wet parts. Per VoxelMatters, OpenCAL machines are now running or under construction at MIT, Purdue University, Lawrence Livermore National Laboratory, and the National Institute of Standards and Technology, along with universities across North America, Europe, and Asia. A primary deployment environment for the system is academic makerspaces, according to the arXiv paper, which frames OpenCAL as a platform for hands-on education in manufacturing technology, photopolymer science, and computational imaging.
A Cheaper Path Than Other DIY Hardware Projects
OpenCAL isn't the first attempt to put advanced fabrication hardware within reach of a hobbyist budget. Michigan Technological University previously published instructions for building a steel 3D printer for just over $1,000, with the bulk of that cost, about $830, going toward a commercial gas-metal arc welder, 3D Printing Industry has reported. Unlike OpenCAL's volumetric approach, that machine worked more like a traditional RepRap design, melting and depositing metal wire one bead at a time rather than forming a whole object at once.
Make: has reported that the OpenCAL team expects partnerships with Formlabs to eventually make the specialized resin available in one-liter quantities for around $100, and the outlet frames the project as a relatively direct path into a fabrication process that would otherwise remain locked inside academic labs. The same outlet notes that machines like OpenCAL can print much faster than traditional methods, with inch-scale objects forming in minutes rather than hours.
