A year ago [Ramy RC] set out on a momentous challenge: to build a 1:21 scale Airbus A380-800 RC model with functional engines, landing gear and all other details. Recently he finished the project and published a video with a summary of the whole build process (also linked below). The full video series can be found on the Ramy RC channel. The final RC airplane came out at a massive wingspan of 3.9 meters (12.7′), a length of 3.6 meters (11.8′) and a weight of 25 kg. This weight is carried by the full landing gear of multiple bogeys that can retract much like on the real airplane.
A range of materials were used for the body, including carbon fiber and wood, with each part carefully modeled with CAD software and 3D-printed or cut on a CNC cutter. Four ducted fans provide the propulsive power that lift this enormous model airplane into the skies, which is the only part where the noise profile doesn’t quite match that of the real A380. Even so, seeing the airplane taxing, taking off and flying through the skies makes you look twice to realize that it is in fact a scale model and not a real Emirates A380-800, also courtesy of the excruciating amount of detail to the model’s final look, down from the logos to the silver-grey lines.
We’re also quite convinced that the maiden flight of such an exquisite model has to be one of the most terrifying experiences imaginable.
For eons, hacker minded people have looked at various items their pile of stuff, came up with an outlandish idea and thought “I wonder if it would work?” Some of us stop there, convincing ourselves that it’s a bad idea that could never work. Others of us such as [Peter Sripol] are well known for not just having those thoughts, but for having the grit to explore them to their impractical limit, such as is shown in the video below the break.
Peter begins by adapting a model airplane propeller to his 9500 RPM battery powered grinder, and then checks thrust with different propellers to see which seemed most efficient. Then [Peter] did what any aerospace engineer out of their right mind would do: He had his brother design the resulting aircraft, which was inspired by an obscure German WWII asymmetric aircraft design.
Did it fly? It did, and you can see a couple of iterations of it tooling around in the video. But what happened next was equally interesting: First, a grinder powered single bladed helicopter and its subsequent hilarious failure, and its slightly more successful successor.
We’ve of course covered many angle grinder hacks, such as this fixture for perfect cuts (something notoriously difficult to do with a handheld grinder), but this is the first time we’ve seen an angle grinder fly out of more than frustration. Do you have your own angle grinder hack to spin our way? Be sure to let the Tip Line know!
What do you do when you have a whole warehouse sized facility and an industrial sized CNC foam cutter? Clearly, the only choice is to build giant RC aircraft, and that’s exactly what the folks at [FliteTest] teamed up with the illustrious [Peter Sripol] to accomplish. Did it work? Yes. Did it work well? We’ll let you be the judge after taking a gander at the video below the break.
[Peter Sripol], known for building manned ultralight electric aircraft from foam, was roped in as the designer of the aircraft. A very light EPS foam is used to cut out the flying surfaces, while a denser green foam board is sourced from the local home building store to construct the fuselage.
The build is anything but ordinary, and kids are involved in the construction, although the video doesn’t elaborate on it very much. You can see evidence of their excitement in the graffiti on the wings and fuselage- surely a huge success on that front! As for flying? Four large motors provide locomotion, and it’s barely enough to keep the beast flying. A mishap with the Center of Gravity demands a last minute design change which renders the rudder almost useless. But, it does fly, and it is a great step toward the next iteration. Just like every good hack!
For a long time radial aircraft engines, with their distinctive cylinder housings arranged in a circle, were a common sight on aircraft. As an experiment, [KendinYap], wanted to see if he could combine 3 small DC motors into a usable RC aircraft motor, effectively creating an electric radial engine.
The assembly consists of three “180” type brushed DC motors, mounted radially in a 3D printed casing. A 3D printed conical gear is attached to each motor shaft, which drives a single output gear and shaft mounted in the center with two bearings. The gear ratio is 3:1. A variety of propellers can be mounted using 3D printed adaptors. As a baseline, [KendinYap] tested a single motor on a scale with a 4.25-inch propeller on a scale, which produced 170 g of thrust at 21500 RPM. Once integrated into the engine housing, the three motors produced 490 g of thrust at 5700 RPM, with a larger propeller. Three independent motors and propellers should theoretically provide 510 g of thrust, so there are some mechanical losses when combining 3 of them in a single assembly. However, it should still be capable of powering a small RC plane. It’s also not impossible that a different propeller could yield better results.
While there is no doubt that it’s no match for a brushless RC motor, testing random ideas just to see if it’s possible is usually fun and an excellent learning experience. We’ve seen some crazy flyable RC power plants, including a cordless drill, a squirrel-cage blower, and a leaf blower.
Conventional airfoil wings have come out on top for getting flying machines airborne over the last century, but there were a few other interesting designs that have come and gone. One of these is the Magnus effect plane, which makes use of the lift produced by a spinning cylinder. [James Whomsley] from [Project Air] decided to build one as a side project, but it ended up being a lot more challenging than what he initially suspected. (Video, embedded below.)
The Magnus effect achieved a bit of viral fame a few years when [How Ridiculous] dropped a basketball down a dam wall with some backspin. [James] T-shaped Magnus effect plane has a pair of spinning cylinders at the top to create lift, driven by a brushless motor using a belt. A second brushless motor with a propeller is on the center carbon fiber tube provides forward thrust, and a rudder provides yaw control. The battery is attached to the bottom of the tub for stability.
The very first flight looked very promising, but [James] quickly ran into a series of problems related to center of gravity, power, pitch control, and drag. After iterations of the build-crash-rebuild cycle, he ended up with larger motors and rudder, shorter “wings”, and a higher thrust motor position. This resulted in a craft still only marginally controllable, but stayed in the air for quite a while. Since the intention was never to turn it into a long-term project, James] called it a success to avoid more yak shaving, and continue work on his airboat and rocketplane.
If you are interested in building one of your own, he put all the findings of his experimentation in a short report. For more inspiration, check out the other Magnus effect plane we covered that used KFC buckets for the wings.
Yaw wag usually occurs on flying wings that use a pair of small winglets instead of a large vertical stabilizer on the centerline. Split rudders, also known as differential spoilers, can be used for active yaw control by increasing drag on either wing independently. However, this requires very rapid corrections that are very difficult to do manually, so this is where ArduPilot comes in. [Think Flight] used its yaw dampening feature in combination with differential spoilers to completely eliminate vertical stabilizers and yaw wag. This is the same technique used on the B-2 stealth bomber to avoid radar reflecting vertical stabilizers. [Think Flight] also used these clamshells spoilers as elevons.
Using XFLR5 airfoil analysis software, [Think Flight] designed built a pair of flying wings to use these features. The first was successful in eliminating yaw wag, but exhibited some instability on the roll axis. After taking a closer look at the design with XFLR5, he found air it predicted that airflow would separate from the bottom surface of the wing at low angles of attack. After fixing this issue, he built a V2 to closely match the looks of the B2 bomber. Both aircraft were cut from EPP foam with an interesting-looking CNC hot wire cutter and laminated with Kevlar for strength. Continue reading “Eliminate Vertical Stabiliser With ArduPlane”→
Electric RC aircraft are not known for long flight times, with multirotors usually doing 20-45 minutes, while most fixed wings will struggle to get past two hours. [Matthew Heiskell] blew these numbers out of the water with a 10 hour 45 minute flight with an RC plane on battery power. Condensed video after the break.
The secret? An efficient aircraft, a well tuned autopilot and a massive battery. [Matthew] built a custom 4S 50 Ah li-ion battery pack from LG 21700 cells, with a weight of 2.85 kg (6.3 lbs). The airframe is a Phoenix 2400 motor glider, with a 2.4 m wingspan, powered by a 600 Kv brushless motor turning a 12 x 12 propeller. The 30 A ESC’s low voltage cutoff was disabled to ensure every bit of juice from the battery was available.
To improve efficiency and eliminate the need to maintain manual control for the marathon flight, a GPS and Matek 405 Wing flight controller running ArduPilot was added. ArduPilot is far from plug and play, so [Matthew] would have had to spend a lot of timing tuning and testing parameters for maximum flight efficiency. We are really curious to see if it’s possible to push the flight time even further by improving aerodynamics around the protruding battery, adding a pitot tube sensor to hold the perfect airspeed speed on the lift-drag curve, and possibly making use of thermals with ArduPilot’s new soaring feature.
A few of you are probably thinking, “Solar panels!”, and so did Matthew. He has another set of wings covered in them that he used to do a seven-hour flight. While it should theoretically increase flight time, he found that there were a number of significant disadvantages. Besides the added weight, electrical complexity and weather dependence, the solar cells are difficult to integrate into the wings without reducing aerodynamic efficiency. Taking into account what we’ve already seen of [rcflightest]’s various experiments/struggles with solar planes, we are starting to wonder if it’s really worth the trouble. Continue reading “Electric RC Plane Flies For Almost 11 Hours”→