How to print high-resolution 3D objects instantly
In the annals of 3D printing, there is one name that rises above all. Adrian Bowyer is the person singularly responsible for the current crop of 3D printers sitting on desktops and workbenches around the world.
In 2005, he founded the RepRap project, a 3D printer with the capability to reproduce some of its own parts. In 2008, the RepRap Darwin, the first Open Source 3D printer, printed most of it’s own parts, creating what was in effect a ‘child’ machine. With that, a 3D printer could make another 3D printer, and so began a revolution in desktop manufacturing.
But as with any machine tool that could be made in someone’s backyard, there were problems. The software wasn’t quite ready yet. The printer was slow, and had relatively low resolution. The filament for this printer was literally weed wacker line, purchased at a hardware store.
Direct-drive extruders had yet to be invented, and everything was pretty much terrible. Give it a decade and a half to spin up, and the RepRap project has evolved into the basis for the foundation of nearly every filament-based 3D printer available today.
But there are still problems with 3D printers. They’re still slow, and printing an object the size of a print bed is a 24-hour job. If you’re using a resin-based printer, it’ll take at least twice as long to print as a filament-based printer. With so much success, there’s still a way to go and again Adrian Bowyer has a printer unlike anything you’ve ever seen.
The Electric 3D Printer
The base research for Bowyer’s new printer comes from three separate ideas that haven’t yet been combined into something new. The first is an Open Source electric 3D scanning technique called Spectra. This is a biomedical 3D scanning device similar to a CAT scan or MRI that uses electricity instead of x-rays or magnetism.
In effect, it’s a bunch of contacts wrapped around a cylinder. Run AC current through a pair of contacts, and you get a measurement of resistance. Do this for multiple pairs of contacts, and you can reconstruct the 3-dimensional volume of whatever is in the chamber. It’s tomography, and in terms of computer graphics isn’t too dissimilar from ray tracing.
The second idea behind the electric 3D printer is a project from Berkeley that prints a 3D object using light, but does it in a fraction of the time of a traditional resin printer.
With the Berkeley project, a DLP projector directs light onto a volume of photocurable resin. Rotate that resin, and what you end up with is basically the reverse of a CT scanner.
The third idea behind the electric 3D printer is electropolimarization. Simply put, you can cure a resin with electricity instead of light.
Put all of these ideas together, and it’s easy to come up with the idea of surrounding a vat of liquid with a series of electrodes. Run AC current through those electrodes just right, and you’ll be able to print a 3D object almost instantly.
The net effect is of a simple machine that will produce an object in seconds. The printer has no moving parts, and all the tools to construct this printer exist today. The only problem? Nobody has done it, so this is completely uncharted territory.
The Electric 3D printer is still in its very early stages of development, but this is a viable idea. At least as much as a ‘CNC hot glue gun’ can become the basis for a desktop manufacturing machine.
Current work is focused on experimenting with ray-tracing (or “reverse tomography”) virtually, with future work that will obviously focus on controlling hundreds or thousands of electrodes around the perimeter of a tank of resin.
Everything available so far is on a GitHub repo, and if you’ve ever wanted to see the growth of a new technology, this is something to watch.