Before little two stroke motors became affordable, and long before electric motors and batteries were remotely possible, there weren’t a lot of options for powering your model aircraft. One technology that really took off was that of rubber band power. By winding a rubber band, it could store enough energy to turn a propeller for a short duration. With a 10 foot model taking the current world record, as you can see in the video below the break [ProjectAir] decided to see if he could beat it.
Starting with a successful free flight aircraft made of foam board, [ProjectAir] simply scaled it up to an eleven foot wing- one foot larger than the ten foot world record holder. Since there were now eight rubber band motors, a mechanism was created to release the propellers in sync, but this was problematic. Eventually a slightly heavy but solid solution was found.
[ProjectAir] did more testing, more problem solving, and through rapid iterations, he eventually was able to have a successful flight under radio control. His personal goal of a 12 second flight was exceeded, and then Guinness called! They’re interested in certifying his attempt as long as his plane can fly for at least 30 seconds- almost double his current ability. What will he do? Check the video, too, for [ProjectAir]’s challenge to the community to join him in trying to beat the world record. Sounds like fun!
Thrift stores, antique shops, knick-knack stores- Whatever you might call them in your locale, they’re usually full of “another man’s treasure”. More often than not, we leave empty-handed, hoping another shop has something we just can’t live without. But on rare occasions, when the bits all flip in our favor, we find real gems that although we have no idea what we’re going to do with them, just have to come home with us.
We’re not going to spoil the goodies, but be sure to read [Charles]’ blog post to see how he hacked a modern 2.4 GHz 7 channel radio into the vintage Futaba 4 channel AM radio case. We appreciated his analytical approach to meshing the older gimbals and potentiometers with the new radio guts. Not to mention what it took to get the Omnibot back into service using parts from his battle bots bin. You’ll love the attention to detail on the new battery, too!
Originally a mere vacuum cleaner, Henry was given movement through two motors and gearboxes sourced from a children’s ride on vehicle. A tank was created out of copper pipe to store the flammable gas (which appears to be butane, as used in cigarette lighters), and discharge is controlled with a solenoid valve. Ignition is then handled by a pair of electric ignitors fired by relay. It’s all controlled over a standard hobby radio controller, so you can stand at a safe distance while flambeeing your rug.
The Flite Test crew is well known for putting some crazy flying contraptions together. They’ve outdone themselves this time with a flying IKEA chair. This build began with [Josh] issuing a challenge to [Stefan]. Take a standard IKEA ladderback chair and make it fly– in less than six hours. With such a tight schedule, measuring twice and cutting once was right out the window. This was a hackathon-style “throw it together and hope it works” build.
The chair was plenty sturdy, so it became the core of the fuselage. [Stefan] grabbed the wing from a previous plane and placed it on the seat of the chair. Two carbon fiber rods drilled into the seat frame formed a tail boom. The tailfeathers were built from Flite Test foam – paper coated foam-core board.
With the structure complete, [Stefan] and his team added servos for control, a beefy motor for power, and some big LiPo batteries. The batteries hung from the bottom of the chair to keep the center of gravity reasonable.
When the time came for the maiden flight, everyone was expecting a spectacular failure. The chair defied logic and leaped into the air. It flew stable enough for [Josh] to take his fingers off the sticks. The pure excitement of seeing a crazy build that works is on full display as the entire Flite Test crew literally jumps for joy. [Alex] even throws in a cartwheel. This is the kind of story we love to cover here at Hackaday – watching a completely nutty build come together and perform better than anyone expected.
RC hovercrafts offer all sorts of design options which make them interesting projects to explore. There are dual-motor ones where one motor provides lift while the other does the thrust. For steering, the thrust motor can swivel or you can place a rudder behind it. And there are single-motor ones where one motor does all the work. In that case, the airflow from the motor blades has to be redirected to under the hovercraft somehow, while also being vectored out the back and steered.
[Tom Stanton] decided to make a single-motor hovercraft using only a single 3D printed piece for the main structure. His goals were to keep it as simple as possible, lightweight, and inexpensive. Some of the air from the blades is directed via ducting printed into the structure to the underside while the remainder flows backward past a steering rudder. He even managed to share a bolt between the rudder’s servo and the motor mount. Another goal was to need no support structure for the printing, though he did get some stringing which he cleaned up easily by blasting them with a heat gun.
From initial testing, he found that it didn’t steer well. He suspected the rudder wasn’t redirecting the air to enough of a sideways angle. The solution he came up with was pretty ingenious, switching to a wedge-shaped rudder. In the video below he gives a the side-by-side comparison of the two rudders which shows a huge difference in the angle at which the air should be redirected, and further testing proved that it now steered great.
Another issue he attacks in the video below was a tendency for the hovercraft to dip to one side. He solves this with some iterative changes to the skirt, but we’ll leave it to you to watch the video for the details. The ease of assembly and the figure-eight drift course he demonstrates at the end shows that he succeeded wonderfully with his design goals.
Instructables user [John_Hagy] and some classmates built an RC hovercraft as their final project in the Robotics Education Lab at NC State University. It’s a foam slab with a Hovership H2204X 2300Kv brushless motor inflating a skirt made out of ripstop nylon. Nylon is great here because it has a low friction coefficient and is nonporous to keep the air in. A second motor propels the craft, with a servo turning the whole motor assembly to steer. The team designed and 3D-printed fan holders which also help channel the air to where it’s supposed to go. Control is via a typical radio-control transmitter and receiver combo.
The project writeup includes a lot of fun detail like previous versions of the hovercraft as well as the research they undertook to learn how to configure the craft — clearly it’s their final paper put on the internet, and well done guys.
[Vimal] tells us that his creation is made up of over 140 unmodified LEGO parts, and is controlled over Bluetooth which connects to an app on his phone. While we would like to see some more detail on the reciprocating module he came up with to drive the boat’s paddles, we have to admit that the images he provided in his flickr album for the project are impeccable overall. If the toy boat game doesn’t work out for [Vimal], we think he definitely has what it takes to get into the advertising department for a car manufacturer.
[Vimal] was even kind enough to provide a LEGO Digital Designer file for the project, which in the world of little rainbow colored blocks is akin to releasing the source code, so you can build up your own fleet before next summer.