The Moxon antenna is named for the late [Les Moxon, G6XN] who first described it in “Two-Element Driven Arrays”, a QST magazine article published in July of 1952. [Bill] built his Moxon loosely based on [Jim/AE6AC's] excellent instructions. The design is incredibly simple – a two element directional antenna using crappie fishing poles as spreaders. That’s crappie as in the fish, not the quality of the pole. Crappie poles are typically made up of telescoping sections of graphite or fiberglass in common lengths of 14, 16, and 20 feet. The poles can be bought for under $20 at sporting goods stores. [Bill] used 16 foot poles purchased from Amazon.
The antenna is created by connecting all four poles at their bases in an X shape. The wire elements are stretched across the ends of the poles. The entire antenna bends up as the stiff poles hold the driven and reflector elements in tension. [Bill] used some scrap wood and U-bolts to attach the fishing poles, and bungee cord ends at the tips. Since the antenna is directional, [Bill] added a TV antenna rotor to spin the beam around. The antenna is so light that one could get by with a couple of cords and the “Armstrong method” of antenna rotation.
Once up on the roof, [Bill] found his antenna really performed. He was easily able to cross the Atlantic from his Northern Virginia home to France, Belgium, and Latvia. The mostly horizontal antenna makes it a bit more unobtrusive than other directional designs. [Bill] mentions that his neighbors haven’t revolted yet, so he’s continuing to enjoy the fruits of his antenna labors.
This year’s Red Bull Creation theme “Reinvent the Wheel” was pretty broad, but the Maker Twins managed to incorporate it quite closely with their winning project which was completed in under 72 hours. They took the idea of urban farming and figured out one way to make farmer’s markets more feasible by helping to eliminate waste and spruce up the presentation of the produce.
The project amounts to a Ferris wheel. Instead of passenger compartments there are modular crates which are built with one wooden pallet each. The wheel itself is chain-driven and allows the system to track where each crate is in the rotation. This data is leveraged for a couple of different uses. One lets the customer select their produce on a tablet app and the crate will rotate into position so they may pick the individual items they want. The machine will also take care of automated watering to ensure the produce on display doesn’t get dried out. The icing on the cake is a separate station for washing and cutting the purchased veggies.
Thank you to Maker Twins for contributing some demonstration “b-roll” for use in this video.
This 3D printed scent distributor was put together by eight people from three states during the 2014 NYC NASA Space Apps Challenge. The team went on to take 1st place in the competition.
The project is called Senti8 and uses a FLORA Arduino micro-controller and a Neopixel LED strip purchased from Adafruit. A smartphone mobile app then remotely connects to the device allowing the user to choose which scent they would like to send to their friend, who is also wearing one of the wristbands.
They came up with the idea by simply asking an American astronaut named [Doug Wheelock] what he missed the most while travelling through the boundless reaches of outer space. To their surprise, he said that the thing he missed the most was his sense of smell.
Originally, the project was envisioned to be a wearable technology for space tourism. But over time, the project morphed into a wristband that would allow people to remember places or planets visited. Even memories unique to those places through scent could be experimented with.
One of the team members, [Brooks], was spotted wearing the Senti8 at the Wearable Tech LA conference in Pasadena, CA on July 17, 2014. The LED lights lining the outside could be seen all the way across the large auditorium as she chatted up with local Crashspace members as they prepared to present their design-oriented hacks to the public.
She gave an interview demoing the wristband which can be seen in the video posted below:
How long have you been making do with a hacked together power supply?
Be sure you vote and you could kiss those days goodbye with this BK Precision 1760A bench supply. It has three channels; 0-30V 0-2A on the first two and 4-6.5V 0-5A on the third. We’re also throwing in some leads so that you can be up and running as soon as it arrives.
We’ll draw a random number on Friday morning. If you have voted at least one time in this current round (your participation in previous rounds doesn’t matter) and your hacker number is drawn you will win! But if your number is drawn and you haven’t voted… no bench supply for you.
Let’s be honest. Paying electricity bills sucks. The amount paid is always too much, and the temperatures in the building are rarely set at a comfortable level. But now, with the help of this DIY Climate Control system, power-users can finally rejoice knowing that the heating and cooling process of their home (or commercial space) can be easily controlled through the utilization of an XBee Remote Kit and a process called zoning.
The team behind the project is [Doug], [Benjamin] and [Lucas]. They hope to solve the inconsistent temperature problems, which are caused by a moving sun, by open-sourcing their work into the community.
Their XBee system runs on a mesh network making it a perfect tool for sensing and communicating which areas in the house are too hot or too cold. Once the data is collected, XBee modules route the information wirelessly to each other until it reaches a central Arduino gatekeeper; which then decides if it wants to heat, ventilate, or air condition the room.
Not to mention all the added benefits posted below:
About a month ago, the FAA – the governing body for nearly everything that flies in US airspace – proposed an interpretation of their rules governing model aircraft. The world hasn’t ended quite yet, but if the proposed rules go into effect, an entire hobby will be destroyed in the United States. While congress has given the FAA authority over nearly everything that flies, there are specific laws saying what the FAA has no jurisdiction over – model aircraft being one of the major exceptions.
Congress, however, is working on a definition of model aircraft that is at least 10 years out of date and doesn’t have any leeway for the huge advances in technology that have happened since then. Specifically, all FPV flight with video goggles would be banned under the proposed FAA rules. Also, because model aircraft are defined as being for, ‘hobby or recreational purposes,’ anyone who flies a model aircraft for money – a manufacturer conducting flight tests on a new piece of equipment, or even anyone who records a video of their flight, uploads it to YouTube, and hits the ‘monetize’ button – would be breaking the law.
The proposed FAA rules for model aircraft are not in effect yet, and you can still make a public comment on the proposal until 11:59 PM EDT Friday. If you leave a comment, please make a well-reasoned statement on why the FAA’s interpretation of the rules governing model aircraft are overly broad, do not take into account technological advances made since the drafting of Congress’ working definition of ‘model aircraft,’ and the effects of a complete ban flying model aircraft for any type of compensation.
Of course, if the proposed rules for model aircraft go through, the only option will be to turn to the courts. Historically, the FAA simply does not lose court cases. Recently, cases involving drones have come up with successful defenses and judges deciding in favor of drone operators. The legal services for the eventual court case challenging the proposed FAA rules will most likely be funded by the Academy of Model Aeronautics, who just so happen to be offering membership at 50% off.
Below is a video of some RC people we really respect – [Josh] from Flite Test and [Trappy] of Team BlackSheep – talking about what the proposed rule change would do to the hobby. There’s also a great podcast featuring the first lawyer to successfully defend drone use in federal court that’s worth a listen.
Conductive ink or paint is lots of fun. It opens up tons of possibilities for flexible and unique circuits — unfortunately, it’s pretty expensive. [Brian McEvoy] shows us how to make your own for cheap, and it works great!
He started trying to formulate his own recipe after playing with other Instructable guides and commercially available paint, and what he found is it’s really not that complex! Graphite powder, acrylic paint, and a jar with an airtight seal — seriously, it’s that simple! But, like any engineer worth their salt (he calls himself the 24 Hour Engineer), he had to do some tests to compare his formula.
In a detailed experiment he compares his formula to the commercially available Wire Glue, and two other recipes using Elmer’s Glue-All and graphite, and Titebond III with graphite. The results? Acrylic paint and graphite produce the most conductive material — and the cheapest!