A liquid-fuel rocket engine is just about the hardest thing anyone could ever build. There are considerations for thermodynamics, machining, electronics, material science, and software just to have something that won’t blow up on the test rig. The data to build a liquid engine isn’t easy to find, either: a lot of helpful info is classified or locked up in one of [Elon]’s file cabinets.
[Graham] over at Fubar Labs in New Jersey is working to change this. He’s developing an open source, 3D printed, liquid fuel rocket engine. Right now, it’s not going to fly, but that’s not the point: the first step towards developing a successful rocket is to develop a successful engine, and [Graham] is hard at work making this a reality.
This engine, powered by gaseous oxygen and ethanol, is designed for 3D printing. It’s actually a great use of the technology; SpaceX and NASA have produced 3D printed engine parts using DMLS printers, but [Graham] is using the much cheaper (and available at Shapeways) metal SLS printers to produce his engine. Rocket engines are extremely hard to manufacture with traditional methods, making 3D printing the perfect process for building a rocket engine.
So far, [Graham] has printed the engine, injector, and igniter, all for the purpose of shoving oxygen and ethanol into the combustion chamber, lighting it, and marveling at the Mach cones. You can see a video of that below, but there’s also a few incredible resources on GitHub, the Fubar Labs wiki, and a bunch of pictures and test results here.
Continue reading “Open Source, 3D Printed Rocket Engines”
Building a MAME machine around a Raspberry Pi has been the standard build for years now, and tiny versions of full-sized arcade machines have gone from curiosity to commonplace. [
The entire enclosure is 3D printed, and most of the electronics are exactly what you would expect: A Raspberry Pi, 2.5″ LCD, and a battery-powered speaker takes up most of the BOM. Where this build gets interesting is the buttons and joystick: after what we’re sure was a crazy amount of googling, [diygizmo] found something that looks like a normal arcade joystick, only smaller. Unable to find a suitable replacement for arcade buttons, [diygizmo] just printed their own, tucked a tact switch behind the plastic, and wired everything up.
Add in some decals, paint, and the same techniques used to create plastic model miniatures, and you have a perfect representation of a miniature arcade machine.
It seems [Andrew] is an up and coming historian for the world of 3D printing. We’ve seen him interview the creator of Slic3r, but this time around he’s headed over to Eindhoven, Netherlands to interview the community manager for Shapeways, [Bart Veldhuizen].
Unlike the RepRaps, Ultimkers, and Makerbots, Shapeways is an entirely different ecosystem of 3D printing. Instead of building a machine that requires many hours of tinkering, you can just upload a model and have a physical representation delivered to your door in a week. You can also upload objects for others to buy. Despite these competing philosophies, [Bart] doesn’t see Shapeways as encroaching on the homebrew 3D printers out there; they serve different markets, and competition is always good.
Unfortunately, [Andrew] wasn’t allowed to film on the Shapeways factory floor. Proprietary stuff and whatnot, as well as a few certain ‘key words’ that will speed your customer support request up to the top of the queue.
As for how Shapeways actually produces hundreds of objects a day, [Andrew] learned that individual orders are made in batches, with several customer’s parts made in a single run. While most of the parts made by Shapeways are manufactured in-house, they do outsource silver casting after making the preliminary positive mold.
As for the future, a lot of customers are asking about mixed media, with plastic/nylon combined with metal being at the top of the list. It’s difficult to say what the future of 3D printing will be, but [Bart] makes an allusion to cell phones from 10 years ago. In 2003, nobody had smartphones, and now we have an always-on wireless Internet connection in our pockets. Given the same rate of technological progress, we can’t wait to see what 3D printing will be like in 10 years, either.
Normally, 29 men walking around in an endless circle would be the stuff of an [M.C. Escher] engraving. [Tobias] turned this into a reality with a little help from some LEDs and a 3D printer.
Like his earlier project, [Tobias] built himself a nice little strobing zoetrope that maintains the illusion of movement by flashing LEDs at precise intervals. Instead of a flat 2D image, [Tobias] went for a walking 3D figure that marches to the beat of a timer circuit. The figures themselves were printed via Shapeways.
The electronics were improved for this iteration. Formerly, [Tobias] used a 555 and a whole bunch of auxiliary components. The circuit was improved for this version to uses Schmitt triggers and an optical encoder. The easy-to-build-on-perfboard schematics and layouts are available, so feel free to build one for yourself.
[Tobias]’ zoetrope isn’t much different from the gigantic Charon sculpture seen at last year’s Burning Man. Sure, it’s not 40 feet tall but it’s still a nice piece of work.
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It’s always interesting to see what happens when hacking meets clothing – check out this pair of bikinis, for instance.
This first item, called the N12 bikini (mildly NSFW), comes from Continuum Fashion and is composed entirely from Nylon 12, hence the name. Shapeways uses 3D Selective Laser Sintering (SLS) to create the tiny circles that make up this piece of swimwear. The suit is held together by tiny stretchy strings made of the same nylon, and the bikini can be printed to order. It seems like an interesting idea, but we wonder how it would hold up against some big waves or a game of beach volleyball.
The second item is a bit more functional. Designer [Andrew Schneider] has put together a bikini that can solve all of your energy needs while sitting by the pool. His solar bikini is covered with hand-sewn flexible solar cells that work together to produce up to 5v, available via a USB connection. He claims that you are free to go swimming in the suit, so long as you dry out the USB port before using it again. For all the guys out there crying foul, don’t worry – he’s got a suit for you too. He’ll be putting together a men’s suit in the near future that powers a 1.5 amp Peltier cooler to keep your beer cold – we just don’t want to know where the hot side of the Peltier goes…
A landmark in home 3d printing was set when [Dr. Ulrich Schwanitz] sent a DMCA takedown notice to Thingiverse.com on users [artur83] and [chylld’s] takes on his Penrose triangle model. ([chylld’s] take is pictured above) While the takedown itself is highly debatable, we do think it’s cool that home 3d printing has come far enough to begin infringing on the copyrights of objects themselves. Right now media pirating has the front stage, but it’s not hard to look a little further into the crazy sci-fi universe that is our future and see a battle being fought over the rights to physical objects.
[via Thingiverse Blog]