Making The Case For Nuclear Aircraft

At any given moment, several of the US Navy’s Nimitz class aircraft carriers are sailing the world’s oceans. Weighing in at 90 thousand tons, these massive vessels need a lot of power to get moving. One would think this power requires a lot of fuel which would limit their range, but this is not the case. Their range is virtually unlimited, and they only need refueling every 25 years. What kind of technology allows for this? The answer is miniaturized nuclear power plants. Nimitz class carriers have two of them, and they are pretty much identical to the much larger power plants that make electricity. If we can make them small enough for ships, can we make them small enough for other things, like airplanes?

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Lithium-Air Might Be The Better Battery

Researchers at Cambridge University demonstrated their latest version of what is being called the Lithium-Air battery. It can be more accurately referred to as a Lithium-Oxygen but Air sounds cooler.

The early estimates look pretty impressive with the energy density being 93% efficient which could be up to 10 times the energy density of Lithium-Ion and claims to be rechargeable up to 2,000 times.  Recent improvements toward Lithium-Air batteries include a graphene contact and using lithium hydroxide in place of lithium peroxide which increased both stability and efficiency.

Here’s the rub: Lithium-Air batteries are still years away from being ready for commercial use. There are still problems with the battery’s ability to charge and discharge (kind of a deal breaker if the battery won’t charge or discharge right?) There are still issues with safety, performance, efficiency, and the all too apparent need for pure oxygen.

Do batteries get you all charged up? Check out our coverage of MIT’s solid state battery research, or have a look at the Nissan Leaf and/or Tesla battery packs.

Thanks to [Jimmy] for the tip.

Magnetic Levitation With Arduino

Getting a magnetic field to balance on another magnetic field is about as easy as balancing a bowling ball on the tip of an ink pen. With a little help from an Arduino mega, however, [EmmaSong] was able to balance a high density neodymium magnet in midair. He pulled off this tricky project using a set of four coils he got off of Taobao (the Chinese version of eBay), a hall effect sensor, and a handful of current regulation ICs.

The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is straightforward. It appears he uses a potentiometer for a rough regulation of the current going to the coils, doing the fine tuning in the code which can be found here (.RAR direct download).

We’ve seen magnetic levitation here before, and this project adds to the list of successful techniques to accomplish this difficult project.

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Are You Telling Me You Built A Lexus…Out Of Cardboard?

So, you want a new Lexus? Well then download yourself a free car, and cut it out on a laser. Add some glue, and bingo, you have yourself a fancy new ride. We’ll, not really.

Sure, this promo video is just a publicity stunt from Toyota (News flash: Your fancy Lexus is actually a Toyota) but we have to hand it to them, it worked. It’s basically 1700 individually shaped, laser cut cardboard cross-sections that are painstakingly stacked and glued together. What we like about this is the technique – that is making a 3D object from 2D.

Using 2D parts to create 3D shapes is nothing new. Most people’s first experience with this technique is with building model airplanes. Instead of cardboard, balsa wood sheets are cut into profiles and connected with stringers to form the shape of a plane. It turns out to be a very efficient way of making 3D structures when you only have 2D materials to work with. And with 3D software now in the hands of the masses, it’s never been a better time to try your hand at building in 3D. For a great example, see this carbon-fiber guitar made using Autodesks free 123D Make software. And don’t limit yourself to parallel layers, you can generate all sorts of shapes including furniture with the free and open source Sketch-Chair software. Which will come in handy, because you’ll most likely need a place to sit while you’re waiting for your new cardboard car to finish printing.

[via CNN]

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Hair Enthusiasts Rejoice! Synthetic Follicles Are Now 3D-Printable

If you’ve been performing painstaking hair-plug procedures on your 3D-printed troll dolls, then prepare to have your world rocked! [Chris Harrison, Gierad Laput, and Xiang “Anthony” Chen] at Carnegie Mellon University have just released a paper outlining a technique they’ve developed for 3D printing fur and hair. Will the figurine section of Thingiverse ever be the same?

The technique takes advantage of a 3D printing effect that most hobbyists actively try to avoid: stringing. Stringing is what happens when the hot end of a 3D printer moves from one point to another quickly while leaking a small amount of molten filament. This results in a thin strand of plastic between the two points, and is generally perceived as a bad thing, because it negatively affects the surface quality of the print.

brush_highresTo avoid this particular phenomenon, 3D printing slicers generally have options like retraction and wiping. But, instead of trying to stop the stringing, [Chris Harrison, Gierad Laput, and Xiang “Anthony” Chen] decided to embrace it. Through extensive experimentation, they figured out how to introduce stringing in a controlled manner. Instead of random strings here and there, they’re able to create strings exactly where they want them, and at specific lengths and thicknesses.

Examples of what this can be used for are shown in their video below, and include adding hair to figurines or bristles to brushes. Of course, once this technique becomes readily available to the masses, the 3D printing community is bound to find unexpected uses for it. 

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Hackaday Links: November 1, 2015

It seems almost compulsory that we start off with a dose of Star Wars. Here’s an epic AT-ST build that motorizes the iconic walker.

That two-legger isn’t going to be lonely. It bigger-slower brother, the AT-AT got a bit of motorized love as well.

What? You were expecting a BB8 build? We have one of those too. [DrYerzinia] has begun a design that hides a quadcopter inside of the BB8. The four 17″ DJI propellers fold up when not in use, extending through hatches in the outer shell when it’s time to take flight. This retains the rolling design you’ve already come to love in the BB8 and we’re going to keep our eyes on it!

Do you have a Teensy and some extra WS2812 strips hanging out on your bench? [etix] put his to use with an ambilight clone. This works really well: simple hardware which connects via USB to communicate with VLC. We applaud [etix’s] choice of Kung Fury as a demo video… a truly bizarre and entertaining short movie. +1000 for its use of VHS tape artifacts.

We just missed Halloween, but this set of wings is far too great of a build to be reserved for that one day. Alas, there is only the demo video but seeing the huge feathered structures fold and unfold is really impressive!

[Truebass] added an artistic accent to one of the walls in his home. He had several cellphone chargers from old phones in his junk bin. These were used to regulate power for some white LEDs. The finished sconces are made from chip-board covered in cherry veneer, all leftover from previous projects.

Want to drink your beer out of beer-byproducts? How about your coffee out of coffee-byproducts. It sounds strange, but 3DOM is marketing it that way, encouraging you to print your beer stein with this beer-byproduct-based 3D printer filament. They also offer coffee filament and have plans for future oddball building materials. Printer inception?

We ran a post about the secret computer of the New York subway system. There wasn’t a ton of information there, but that could change. The New York Historical Society is running a Kickstarter to expand their Computing History made in NY.

The Flying Man

No, that’s not a typo for Burning Man. What do you get when you take a hundred feet of plastic sheet, weld up a big ramp, modify a car into your own personal high speed winch, and put it all near a lake? You get some serious air time.

A group of French water sports enthusiasts decided to build this fantastically ill-advised super slip and slide. They built a giant ramp alongside an old farm house heading towards the lake. At the bottom is a large ramp they welded together out of steel. Now you can just slide down this slip and slide.

But they weren’t content with just that.

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