Computed Axial Lithography (CAL) is a lighting-fast form of volumetric 3D printing that holds incredible promise for the future, and [The Action Lab] filmed it in action at a Berkeley team’s booth at the “Open Sauce” convention.
The basic principle works like this: an extra-viscous photopolymer resin sits inside a rotating, transparent cylinder. As the cylinder rotates, UV light is projected into the resin in patterns carefully calculated to reproduce the object being printed. There are no layers, no FEP, and no stop-and-start; it’s just one long exposure from what is effectively an object-generating video, and it does not take long at all. You can probably guess that the photo above shows a Benchy being created, though unfortunately, we’re not told how long it took to produce.
Don’t expect to grab a bottle of SLA resin to get started: not only do you need higher viscosity, but also higher UV transmission than you get from an SLA resin to make this trick work. Like regular resin prints, the resolution can be astounding, and this technique even allows you to embed objects into the print.
It’s not a new idea. Not only have we covered CAL before, we even covered it being tested in zero-G. Floating in viscous resin means the part couldn’t care less about the local gravity field. What’s interesting here is that this hardware is at tabletop scale, and looks very much like something an enterprising hacker might put together.
Indeed, the team at Berkeley have announced their intention to open-source this machine, and are seeking to collaborate with the community on their Discord server. Hopefully we’ll see something more formally “open” in the future, as it’s something we’d love to dig deeper into — and maybe even build for ourselves.
Thanks to [Beowulf Shaeffer] for the tip. If you are doing something interesting with photopolymer ooze (or anything else) don’t hesitate to let us know!
Urgh – this is wiiiiiild. Tomography and the maths associated with it is brain-hurty. The resulting parts still look pretty beta but so did early 3d prints. Can’t wait for this to trickle down.
“Like a record, baby, right round, round round!”
Is it just me or is hackaday like a week or two behind what happening? Learned about this from the action lab already.
Hackaday aggregates links from other sources, so it’s never bleeding-edge.
Very cool
Does this mean resin printing can now work without supports?
yeah if youre only printing teeny little things with highly specialized resin. Teeny is good though since in most cases so far you cannot reuse the remainder of the resin after your part is extracted.
The question is: what is the resulting material like and what are its properties.
Because obviously you have way less choice in the material, and you have to deal with limitations I’m sure but are those limitations a deal killer? If for instance it’s brittle and weak or rubbery or flammable or or..
Good question!
This particular setup isn’t bragging, but other sources talking about closed-source CAL projects make it sound like the resin can be adapted to have different mechanical properties just like with traditional SLA. That makes sense to me. It’s a bit thicker and more transparent to UV, but ultimately the goop in this machine is still UV-cure resin, with all the pros and cons that come with that.