There are subtle differences between 3D printing types that seem at first to be the same.<p>Stereolithography is horizontal, one layer at a time, and uses photopolymerization (that's Formlabs). (Also Digital Light Processing is close but distinct: <a href="https://formlabs.com/blog/3d-printing-technology-comparison-sla-dlp/" rel="nofollow">https://formlabs.com/blog/3d-printing-technology-comparison-...</a>)<p>Continuous Liquid Interface Production (CLIP) also uses photopolymerization, but pulls the object from a liquid bath and uses a buffer zone. Still horizontal slices. The upshot is it's much faster. (Carbon 3D is the company behind this.)<p>The method in the article uses photopolymerization to solidify the object as a set of slices, but the slices are not horizontal.<p>The big drawback to photopolymerization is it only works on certain resins which can often have undesirable mechanical properties (high elasticity or brittlness, for e.g.) Potentially this method could be a way forward in that respect, because you might be able to put structural materials in the resin solution and end up with a composite. It seems easier to do this way than with CLIP or SLA/DLP, but I'm purely speculating.
If I understand this correctly, there's nothing to stop them from...<p>* rotating the projector instead of the tube to reduce distortion from resin movement (like in a CT scanner)<p>* speeding this up, using higher energies to compensate<p>* using multiple projectors at e.g. 90degree angles, to reduce time (and thus probably distortions through movement in the resin)<p>* using other wavelengths with e.g. more energy, or just better absorption properties for the resin<p>or are there any obvious problems with that?
steriolithography[1] is neat, and i think older than deposition style printers.<p>This is kinda wacky. Rather than a conceptually simple layer by layer approach, this has this funky convolution. they're getting it for free with the simple rotation. You can kinda see how bulbous that airplane model is, because some finer details get 'overexposed'. i bet, if they could rotate 10x around 1 axis and 1x around another axis, that tumble would sharpen up some of those edges, since you wouldn't be baking the same adjacent space so much.<p>Think about a 6 sided pencil. if you just rotate around the main axis, it's probably going to look pretty round without the crisp hexagon sides. but if you can also rotate around a minor axis, you could also project just the hexagon shape for a while and still preserve the cone of the tip of the pencil since most of the solidification came from the sides.<p>There's an opportunity for deep optimization there. Seems tricky. but pretty cool.<p>it's almost like pca. what projection (or series of projections) maximize hitting the target, and minimize the overbaking, all while taking into account the characteristics of the resin. maybe you can let it cool for a bit, and have more freedom to expose without hardening.<p>also, not a replicator. this is just one _fabulously special_ super material you mess with, not metal and plastic and cloth and fur and chitin and whatever.<p>[1] <a href="https://en.wikipedia.org/wiki/Stereolithography" rel="nofollow">https://en.wikipedia.org/wiki/Stereolithography</a>
Uh, that's a standard resin printer. Except horizontal plus rotation instead of vertical. Trades angular resolution for vertical.<p>Yes, they can be fast.<p>They should fix their headlines.
These resin printers have been around for a decade. Multiple kickstarters, several commercial models on sale right now.<p>To classify as a ‘replicator’ it needs to be able to mix different materials (metal, plastic) seamlessly in one print as to be able to replicate itself. Not there yet...
>> The device, described on 31 January in Science1, works like a computed tomography (CT) scan in reverse, explains Hayden Taylor, an electrical engineer at the University of California, Berkeley.<p>I have been wondering if something like that was possible. I've also wondered if something more akin to holography could be used to create a 3D interference pattern in a liquid to create an object. Both seem like they'd be interesting and have limitations.<p>From the comments here I think some folks don't realize the mathematical details involved in this - they are not projecting a "picture" of the object from each angle going around. Yes, it's an image, but not it's not what you'd expect. It's more akin to an x-ray of the object, and probably with some extra processing beyond that.<p>EDIT: Looks like I'm wrong. It says the create an image of what the object would look like from each angle. I believe that means their quality is lower than it could be had they actually used more sophisticated methods to create the images.
> <i>The team realized that the process could be reversed: given a computer model of a 3D object, the researchers calculated what it would look like from many different angles, and then fed the resulting 2D images into a ordinary slide projector.</i><p>I'm pretty sure the researchers were using a normal computer projector and not a slide projector. But in my imagination, they printed a bunch of slides, fed them into a carousel projector, and pointed them at an old Smuckers jelly jar full of resin.
While you end up with an acrylic model, this should be suitable for lost-wax style casting. Being able to create an unpixilated identical or scaled copy of a model will be fantastic for fine art sculpture (or destroy the industry, if copies become too easy to make). Just take your acrylic model, attach casting channels, cover in ceramic, dry, pour in your bronze, cool, crack, trim, patina, ship. Avoid all of the fiddly mold making and wax finishing completely.
This is very similar to a patent I have filed on extremely fast 3D printing.<p>I have mentioned this method of 3D printing here previously. Transmitting data to a volume at high speed can be done in many different ways, at any scale, and with a variety of materials.<p>I hope to someday demonstrate the printing of a 2 story concrete house in an hour using my technique.
This is new to me and looks really cool despite the sensational style of journalism. I imagine in the near future we will have a variety of widely available methods for making physical objects from digital models, each with advantages and disadvantages for different usecases.
Something similar was proposed back when 3d printing as we know it today was getting started in the 1980s. Two lasers were shined through a photocurable resin so that the resin would cure at the interesection[0](see figure 9). In practice it never worked and the resin cured before intersecting leading to nasty blobs rather than parts. It seems that now that we understand the kinetics of photocuring better and that we have massive amounts of computer that we're able to use these approaches. Processes that cure resin have a lot of potential because resolution can potentially be on the order of that of the wavelength of light.
[0]<a href="https://pdfs.semanticscholar.org/4716/c69f0b90a158589e54248a524a57ad78f4a3.pdf" rel="nofollow">https://pdfs.semanticscholar.org/4716/c69f0b90a158589e54248a...</a>
The speed is amazing but the amount of waste seems rather large as they most likely can't (re)use resin that has already absorbed (an unknown amount of) light before.
Sorry am I missing something? 15 years ago we had one of these in our engineering lab. 3d Printing wasn't a rage term yet, it was called "rapid prototyping resin machine".
There is a more volumetric 3d printing method which prints all at once, no rotation required: <a href="https://www.llnl.gov/news/volumetric-3d-printing-builds-need-speed" rel="nofollow">https://www.llnl.gov/news/volumetric-3d-printing-builds-need...</a>
I don't fully understand the process of creating 3D video from 2D slices. Is that some sort of holographic procedure?<p>Presumably such a video could also easily be computed from CAD models, right?