The EM Drive Might Not Work, But We Get Helicarriers If It Does

August 19, 2015 by Brian Benchoff 226 Comments

There is a device under test out there that promises to take humans to another star in a single lifetime. It means vacations on the moon, retiring at Saturn, and hovercars. If it turns out to be real, it’s the greatest invention of the 21st century. If not, it will be relegated to the history of terrible science right underneath the cold fusion fiasco. It is the EM drive, the electromagnetic drive, a reactionless thruster that operates only on RF energy. It supposedly violates the laws of conservation of momentum, but multiple independent lab tests have shown that it produces thrust. What’s the real story? That’s a little more complicated.

The EM Drive is a device that turns RF energy — radio waves — directly into thrust. This has obvious applications for spacecraft, enabling vacations on Mars, manned explorations of Saturn, and serious consideration of human colonization of other solar systems. The EM drive, if proven successful, would be one of the greatest inventions of all time. Despite the amazing amount of innovation the EM drive would enable, it’s actually a fairly simple device, and something that can be built out of a few copper sheets.

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Hackaday Prize Entry: Project Dekoboko 凸凹 Maps Bumpy Roads On A Bike

August 17, 2015 by Richard Baguley 13 Comments

If you live in New England (like me) you know that the roads take a pounding in the winter. Combine this with haphazard maintenance and you get a recipe for biking disaster: bumpy, potholed roads that can send you flying over the handlebars. Project Dekoboko 凸凹 aims to help a little with this, by helping you map and avoid the bumpiest roads and could be a godsend in this area.

The 2015 Hackaday Prize entry from [Benjamin Shih], [Daniel Rojas], and [Maxim Lapis] is a device that clips onto your bike and maps how bumpy the ride is as you pedal around. It does this by measuring the vibration of the bike frame with an accelerometer. Combine this with a GPS log and you get a map of the quality of the roads that helps you plan a smooth ride, or which could help the city figure out which roads need fixing the most.

The project is currently on its third version, built around an Arduino, Adafruit Ultimate GPS Logger shield, and a protoboard that holds the accelerometer (an Analog ADXL345). The team has also set up a first version of their web site, which contains live data from a few trips around Berlin. This does show one of the issues they will need to figure out, though: the GPS data has them widely veering off the road, which means that the data was slightly off, or they were cycling through buildings on the Prinzenstrasse, including a house music club. I’ll assume that it was the GPS being inaccurate and not them stopping for a rave, but they will need to figure out ways to tie this data down to a specific street before they can start really analyzing it. Google Maps does offer a way to do this, but it is not always accurate, especially on city streets. Still, the project has made good progress and could be useful for those who are looking for a smooth ride around town.

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Dutch Student Team Aims To Launch Rocket To 50KM

August 14, 2015 by Richard Baguley 15 Comments

Space. The final frontier. These are the voyages of DARE, the [Delft Aerospace Rocket Engineering] team, who are looking to launch a rocket to 50 kilometers (about 31 miles) to break the European amateur rocketry record later this year.

This brave crew of students from the Delft Technical University is boldly going where no European amateur has gone before with a rocket of their own design called Stratos II, a single stage hybrid rocket which is driven by a DHX-200 Aurora engine. This self-built engine uses a combination of solid Sorbitol and candlewax fuel, with liquid Nitrous Oxide as the oxidizer. The rather unlikely sounding combination should produce an impressive 12,000 Newtons of maximum thrust, and a total of 180,000 Ns of impulse. It’s difficult to make a proper comparison, but the largest model rocket motor sold in the US without a special license (a class G) has up to 160 Ns of impulse and the largest engine ever built by amateurs had 411,145 Ns of impulse.

The team did try a launch last year, but the launch failed due to a frozen fuel valve. Like any good engineering team, they haven’t let failure get them down, and have been busy redesigning their rocket for another launch attempt in the middle of October, Their launch window begins on October 13th at a military base in southern Spain, and we will be watching their attempt closely. Godspeed, DARE!

In commercial space news, yesterday NASA tested the RS-25 engine that will be used in the Space Launch System — the rocket it’s developing to take astronauts to the moon and mars. Also, the NTSB report on the tragic crash of SpaceShipTwo was released a few weeks ago. The report found that the feather mechanism was unlocked by the copilot at the wrong time, leading to the crash. Future system improvements will be put in place to ensure this doesn’t happen again.

Update – The Stratos II is a single-stage rocket, not a two-stage, as an earlier version of this article described. 8/16/15

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Segway Build You Can Do Yourself

August 11, 2015 by James Hobson 8 Comments

We’ve seen lots of Segway variants on Hackaday, but they don’t always have detailed instructions on how they made it… Well lucky for us, [Bob] from [Making Stuff] just finished his extensive Segway project with tons of videos of the build!

Inspired by other self-balancing scooter projects he had seen online, [Bob] wanted to try his hand at building one. So he took bits and pieces from designs he liked, and came up with his own solid looking Segway clone design. Using Google Sketchup he drew up the frame, and from there it was all hands on deck. A bit of TIG welding later and it was time for the components.

Some small slight mechanical hiccups aside, the longest part of the project was the electronics and software — getting it to work like a real Segway. After writing his own code he ran into a few roadblocks, but luckily he was able to get some help from someone at his local Maker meetup which saved a lot of troubleshooting on his end.

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The French Built The Superconducting Hoverboard 4 Years Before Lexus

August 10, 2015 by James Hobson 27 Comments

The internet only just got over Lexus’ real working hover board, but as it turns out, a team of researchers from the University of Paris Diderot already built one, over 4 years ago (machine translation)!

Using the same principles as the hover board Lexus build, the researchers built a very expensive neodymium magnet track to test the board on. Only difference here is that they didn’t hide the magnets. The hover board itself was machined out of wood, and houses a large sealed metal tray which contains the superconducting bricks.

Pour in some liquid nitrogen through the funnel, and you’re ready to witness some of the quantum properties of superconductors! The board floats a few centimeters above the magnetic rails, and in their tests was able to lift people over 100 kg in weight (hint for most Americans… there are 2.2 pounds to one kilogram).

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The Self-Balancing Sideways Segway

August 1, 2015 by James Hobson 13 Comments

[Jason Dorie] has been hard at work on his two-wheeled, self-balancing skateboard. He calls it the Sideway.

Similar to the Segway, it relies on the user shifting their weight to control the speed at which it will run. A Wii Nunchuk controller is used to steer, which varies each wheels output, which allows for some tight maneuvering!

Under the deck is a pair of 24V 280W (about 1/3HP each) scooter motors which are driven by two 32A Sabertooth speed controllers. They’re run off a pair of 3 cell 5Ah LiPos which get him about 40 minutes of use — not too shabby! To handle the control algorithm for the IMU, he’s using a Parallax Propeller with custom software.

To demonstrate, he takes us of a tour of one of his favorite stores — Michael’s.

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Trying To Set Things On Fire, You Know…for Science.

July 25, 2015 by George Graves 26 Comments

This video from [Just Think] caught our attention for open-flame testing of 6 different commonly used liquid fuels: Jet-A, diesel, heating oil, kerosene, avgas (100LL), and gasoline (or petrol, for our international readers). We love his low-tech approach to testing – just some mason jars and a back yard. The results are quite interesting.

He starts with testing Jet-A fuel. Yep, the same stuff you’d fill up your Boeing 737 with. We flinched for a second as he drops a match into it – then nothing happened. It’s a common misconception that jet fuel will sustain a flame by its self. It needs to be atomized to burn, as he shows in the video. He moves on to test both diesel and heating oil – making note that both are exactly same, except for color. Heating oil has a red dye added to it, to mark it “not for sale” for cars and trucks, as it’s not taxed. Neither would keep a flame.

Next up is kerosene, and it would just barely keep a flame. kerosene is commonly used as a replacement for diesel in extremely cold climates, were diesel fuel would gel and clog fuel systems. Finally, he tests avgas and gasoline. Both would sustain a flame quite well.

We think this small experiment is interesting, in that the results are kind of counter-intuitive. All these different fuels are used in different applications because of their different properties, and of course there is some really interesting science behind that, if you want to learn more.

We don’t need to tell you to be safe when working with fuels. Even though something like Jet-A fuel won’t carry a flame in a container on its own, doesn’t mean that it won’t burn aggressively when combined with other things (like clothing) and in other situations. So we’re filing this one under “don’t try this at home” – instead, sit back and enjoy the YouTube video after the break.

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