Most of us have printed a few benchies to test our 3D printers. The intrepid little boat has a variety of features that tax different parts of the printing process. However, the guys at [FliteTest] had a different idea. They set out in a competition to build a giant flying benchie. They aren’t quite done, but they did make some interesting progress, as you can see in the video below.
In all fairness, the benchies are not, themselves, 3D printed. Foamboard, however, is a bit more practical. Inevitably, you can’t help but think of a flying boat when you see the results.
LEONARDO, a somewhat tortured name derived from “LEgs ONboARD drOne,” is actually just what it appears to be: a quadcopter with a set of legs. It comes to us from Caltech’s Center for Autonomous Systems and Technologies, and the video below makes it easy to see what kind of advantages a kinematic mash-up like this would offer. LEO combines walking and flying to achieve a kind of locomotion that looks completely alien, kind of a bouncy, tip-toeing step that really looks like someone just learning how to walk in high heels. The upper drone aspect of LEO provides a lot of the stabilization needed for walking; the thrust from the rotors is where that bouncy compliance comes from. But the rotors can also instantly ramp up the thrust so LEO can fly over obstacles, like stairs. It’s also pretty good at slacklining and skateboarding, too.
It’s easy to see how LEO’s multimodal locomotion system solves — or more accurately, avoids — a number of the problems real-world bipedal robots are going to experience. For now, LEO is pretty small — only about 30″ (76 cm) tall. And it’s rather lightly constructed, as one would expect for something that needs to fly occasionally. But it’s easy to see how something like this could be scaled up, at least to a point. And LEO’s stabilization system might be just what its drunk-walking cousin needs.
It is unlikely that as a young lad [Richard Jenkins] would had have visions of sailing into the eye of a Category-4 hurricane. Yet that’s exactly what he’s done with the Explorer 1045, an uncrewed sailing vehicle built by his company, Saildrone. If that weren’t enough, footage from the vessel enduring greater than 120 MPH (almost 200 km/h) winds and 50 foot (15 M) waves was posted online the very next day, and you can see it below the break. We’re going to take a quick look at just two of the technologies that made this possible: Advanced sails and satellite communication. Both are visible on Explorer 1045’s sibling 1048 as seen below:
Saildrone Explorer 1048, a sibling of Explorer 1045, each one of five vessels equipped with a “hurricane wing”
The most prominent feature of course is the lack of a traditional sail. You see, from 1999-2009, [Richard Jenkins] was focused on setting the land world speed record for a wind powered vehicle. He set that record at 126.1 mph by maturing existing sail wing technology. [Richard] did away with conventional rigging and added a boom with a control surface on it, much like the fuselage and empennage of a sailplane.
Instead of adjusting rigging, the control surface could be utilized to fly the wing into its optimal position while using very little energy. [Richard] has been able to apply this technology at his company, Saildrone. The 23 foot Explorer vessel and its big brothers are the result.
How is it that the world was treated to the view from inside the eye of a hurricane only a day after the video was recorded? If you look at the stern of the vessel, you can see a domed white cylinder. It is a satellite communication base station called the Thales VesseLINK. Thales is one of the partner companies that built the satellites for the Iridium NEXT fleet, which has 66 operational satellites in Low Earth Orbit. The Iridium Certus service uses its L-Band (1.6 GHz) signal to provide up to 352 kbps of upload speed and 704 kbps down. While not blazing fast, the service is available anywhere in the world and is reliable because it is not prone to rain fade and other weather based interference.
With just these two recent innovations, the Explorer 1045 was able to sail to the eye of a hurricane, record footage and gather data, and then ship it home just hours later. And we’re hardly exploring the tip of the iceberg. More than just sailboat based cameras, these scientific instruments are designed to survive some of the harshest environments on the planet for over a year at a time. They are a marvel of applied engineering, and we’re positive that there are some brilliant hacks hiding under that bright orange exterior.
For a long time fixed wing VTOL drones were tricky to work with, but with the availability of open source flight control and autopilot software this has changed. To make experimentation even easier, [Stephen Carlson] and other researchers from the RoboWork Lab at the University of Nevada created the MiniHawk, a 3D printed VTOL aircraft for use a test bed for various research projects.
Some of these project include creating a longer wingspan aircraft by combining multiple MiniHawks in mid-flight with magnetic wing-tip mounts, or “migratory behaviors“. The latter is a rather interesting idea, which involves letting the craft land in any suitable location, and recharging using wing mounted solar panels before continuing with the next leg of the mission. With this technique, the MiniHawk could operate on mission almost indefinitely without human intervention. This is a departure from some other solar planes we’ve seen, which attempt to recharge while flying, or even ditch batteries completely, which limits operation to sunny weather conditions.
The design is open source, with all the relevant information and files available on GitHub. This looks like a fun craft even if you don’t plan on doing research with it, and [Stephen] also created an FPV specific canopy cover.
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.
[rctestflight] has built several autonomous boats, and with missions becoming longer and more challenging, he bought an inflatable kayak to serve as a dedicated rescue vessel. Instead of relying on outdated manual paddling, he built an autonomous solar-powered tugboat.
♪ “Rum, treasure, ArduRover, Pixhawk 4 and so much solar, break of dawn till the day is over, the ship will surely go…” ♪
The tugboat uses a pair of molded fiberglass hulls in a catamaran configuration. The wide platform allows a pair of 100W solar panels to be mounted on top. It was [rctestflight]’s first time molding anything out of fiberglass, so there was quite a bit of trial and error going on. The mold was 3D printed in sections, aligned with dowel pins, and glued together. After the epoxy had cured, the mold halves could be split apart for easier removal of the hull.
As with most of [rctestflights] autonomous vehicles, control is handled by a Pixhawk 4 running ArduPilot/ArduRover. A pair of 76 mm brass propellers powered by brushless motors provide propulsion and differential steering. The motors get power from six LiFePO4 batteries, which charge from the solar panels via MPPT charge controllers. The hulls are covered with plywood decks with removable hatches and inspection windows. After a bit of tuning, he took the boat for a few test runs, the longest being 5.1 km with himself in tow in the kayak. At less than 5 km/h (3 mph) it’s no speedboat, but certainly looks like a relaxing ride. Many of [rctestflight]’s previous vessels were airboats to avoid getting underwater propellers tangled in weeds. It was less of an issue this time since he could just haul the tugboat close to the kayak and clear the propellers.
[rctestflights] are always entertaining and educational to watch, and this one certainly sets the standard for sea-shanty soundtracks at 13:32 in part two.
One of the major perks of all the affordable flight controllers and motors available from the hobby market is that you can really experiment with some crazy aircraft designs. [amazingdiyprojects] is experimenting with a coaxial helicopter design, with the goal off possibly using for a manned version in the future. (Video link, embedded below.)
The aircraft uses a pair of coaxial counter-rotating motors with large propellers, with several redundant control surfaces below the propellers. One of the theoretical advantages of this arrangement, compared to the more conventional quadcopter type designs, is redundancy. While a quadcopter will start tumbling when a single motor fails, this design will still be able to descend safely with just one motor.
It is also not dependent on the main motors for yaw, pitch and roll control. In multirotors, the motors need to keep a significant amount of the motor’s available power in reserve to increase torque at a moment’s notice for attitude control. This craft can use all the available thrust from the motors for lift, since control is provided by the control surfaces. There are five sets of redundant control surfaces below the propellers, each set connected to a separate flight controller.
Another advantage of this design is efficient for a given footprint, since one large propeller will always be more efficient than multiple smaller propellers. One of the goals for [amazingdiyprojects] is to fit the full size craft in a shipping container or on a trailer for transport without dissasembly.
