Two robots enter, one robot leaves! Combat robotics are a fantastic showcase of design and skill, but the mechanical contenders don’t have to be big, heavy, and expensive. There is an Antweight division for combat robots in which most contenders weigh a mere 150 grams, and [Harry Makes Things] shows off four participants for Antweight World Series (AWS) 64.
Clockwise: ReLoader, Shakma, Sad Ken, and HobGoblet antweight combat robots.
Each of them have very different designs, and there are plenty of photos as well as insightful details about what was done and how well it worked. That’s exactly the kind of detail we love to read about, so huge thanks to [Harry] for sharing!
In combat robotics, contenders generally maneuver their remote-controlled machines to pin or immobilize their opponent. This can happen as a result of damaging them to the point that they stop functioning, but it can also happen by rending them helpless by working some kind of mechanical advantage. Continue reading “Small Combat Robots Pack A Punch In Antweight Division”→
Aviation consists of two major groups. Airplane enthusiasts, and helicopter enthusiasts. The two groups rarely get along, each extolling the virtues of their chosen craft. Somewhere in between are autogyro folks. People who like vehicles that blend the best (or worst) of both airplanes and helicopters. Aviation master [Peter Sripol] has dipped his toes into the autogyro world, but not without some trouble.
Autogyros are propelled by a propeller, like a plane. They also have a tail section that works similar to a fixed-wing aircraft. That’s where the similarities end though. Lift for autogyros comes in the form of a rotating set of blades, much like a helicopter. Autogyro rotors aren’t powered during flight. They utilize autorotation. The blades freewheel, spun by the air as the craft moves forward.
[Peter] recently got his hands on a full-scale autogyro. So it made sense to build a model to help learn to fly. This isn’t [Peter’s] first attempt with autogyro models. He’s built a few in the past, with limited success. This time he started from scratch and ran into even more problems!
While wheels might seem like a foundational technology, they do have one major flaw: they typically need maintained roads in order to work. Anyone who has experience driving a Jeep or truck off-road likely knows this first-hand. For those with extreme off-road needs the track is often employed. [Let’s Print] is working on perfecting his RC tracked vehicle to take advantage of these perks using little more than 3D printed parts and aluminum stock.
This vehicle doesn’t just include the 3D printed tracks, but an entire 3D printed gearbox and drivetrain to drive them. Each track is driven by its own DC motor coupled to a planetary gearbox to give each plenty of torque to operate in snow or mud. The gearbox is mated to a differential which currently shares a shaft, which means that steering is currently not possible. The original plan was to have each motor drive the tracks independently but a small mistake in the build meant that the shaft needed to be tied together. [Let’s Print] has several options to eventually include steering, including an articulating body or redesigning the drivetrain to be able to separate the shaft.
While this vehicle currently has no wheels in order to improve traction, [Let’s Print] does point out that a pair of wheels could complement this vehicle when he finished the back half of it since wheels have a major advantage over tracks when it comes to steering. A vehicle with both could have the advantages of both, so we’re interested to see where this build eventually goes.
The core of this project is a battery-powered belt sander by a well known manufacturer of gnarly yellow power tools. With an eye for using bespoke 3D printed parts, the conversion appeared straightforward – slap on (or snap on) a pre-loved steering mechanism, add a servo for controlling the sander’s trigger, and that’s pretty much job done. Naturally the intention was to use sandpaper as tread, which is acceptable for outdoor use but not exactly ideal for indoors. A thermoplastic polyurethane (TPU) tread was designed and printed for playtime on the living room floor, where sandpaper may be frowned upon.
The finished product is a mean looking toy with plenty of power. What we really like most about this hack is the commitment to the aesthetics. It’s seriously impressive to see a belt sander so convincingly transformed into a three-wheeler radio-controlled car. The final iteration is also completely reversible, meaning that your belt sander can keep on sanding two by fours on the job site. All the printed parts snap snug into place and are mostly indistinguishable from the stock sander.
Speaking of reversible, there were just a couple of issues with the initial design, if you catch our drift. We won’t spoil what happens, but make sure to watch the video after the break for the full story.
With all the futuristic technology currently at our disposal, it seems a little bizarre that most passenger vehicles are essentially the same thing that they were a century ago. Four wheels, a motor, and some seats would appear to be a difficult formula to beat. But in the 3D printing world where rapid prototyping is the name of the game, some unique vehicle designs have been pushed out especially in the RC world. One of the latest comes to us from [RCLifeOn] in the form of a single-wheeled RC snowmobile.
While not a traditional snowmobile with tracks, this one does share some similarities. It has one drive wheel in the back printed with TPR for flexibility and it also includes studs all along its entire circumference to give it better traction on ice. There are runners in the front made from old ice skates which the vehicle uses for steering, and it’s all tied together with an RC controller and some lithium batteries to handle steering and driving the electric motor.
There were some design flaws in the first iteration of this vehicle, including a very large turning radius, a gearing setup with an unnecessarily high torque, and a frame that was too flexible for the chain drive. [RCLifeOn] was also testing this on a lake which looked like it was just about to revert to a liquid state which made for some interesting video segments of him retrieving the stuck vehicle with a tree branch and string. All in all, we are hopeful for a second revision in the future when some of these issues are hammered out and this one-of-a-kind vehicle can really rip across the frozen wastes not unlike this other interesting snowmobile from a decade ago.
eVTOL (Electric Vertical Take-off and Landing) craft are some of the more exciting air vehicles being developed lately. They aim to combine the maneuverability and landing benefits of helicopters with the environmental benefits of electric drive, and are often touted as the only way air taxis could ever be practical. The aircraft from Joby Aviation are some of the most advanced in this space, and [Peter Ryseck] set about building a radio-controlled model that flies in the same way.
The design is inspired by the Joby eVTOL test vehicle.
The result is mighty complex, with six tilt rotors controlled via servos for the utmost in maneuverability. These allow the vehicle to take off vertically, while allowing the rotors to tilt horizontally for better efficiency in forward flight, as seen on the Bell-Boeing V-22 Osprey.
The build uses a 3D-printed chassis which made implementing all the tilt rotor mounts and mechanisms as straightforward as possible. A Teensy flight controller is responsible for controlling the craft, running the dRehmFlight VTOL firmware. The assembled craft only weighs 320 grams including battery; an impressive achievement given the extra motors and servos used relative to a regular quadcopter build.
With some tuning, hovering flight proved relatively easy to achieve. The inner four motors are used like a traditional quadcopter in this mode, constantly varying RPM to keep the craft stable. The outer two motors are then pivoted as needed for additional control authority.
In forward flight, pitch is controlled by adjusting the angle of the central four motors. Roll is achieved by tilting the rotors on either side of the plane’s central axis, and yaw control is provided by differential thrust. In the transitional period between modes, simple interpolation is used between both modes until transition is complete.
Outdoor flight testing showed the vehicle is readily capable of graceful forward flight much like a conventional fixed wing plane. In the hover mode, it just looks like any other multirotor. Overall, it’s a great demonstration of what it takes to build a successful tilt rotor craft.
Looking to recreate those relaxing Minecraft fishing sessions in real life, [electrosync] recently set out to 3D print himself a blocky remote controlled boat, complete with a similarly cubic occupant to ride in it. Each element of the build, from the oars to the bobber on the end of the fishing line, has been designed to look as faithful to the source material as possible. In fact, the whole thing is so accurate to the game that it’s almost surreal to see it rowing around the pool.
That said, some of the resemblance is only skin deep. For example the rowing action, though it appears to be properly synchronized to the boat’s movement through the water, is completely for show. A standard propeller and rudder arrangement under the boat provide propulsion and directional control, and [electrosync] notes its actually powerful enough to push the boat very near to its scale top speed from the game, despite the exceptionally poor hydrodynamics of what’s essentially just a rectangle.
A look under the deck.
Speaking of which, [electrosync] even went through the trouble of printing the hull in wood-fill PLA and coating it in polyester resin to make sure it was watertight. Granted he could have just made the boat out of wood in the first place, saving himself the nearly 60 hours it took to print the hull parts, but that would have been cheating.
Beyond the servos and motors that move the boat and the oars, [electrosync] had to give his 3D printed fisherman a considerable amount of dexterity. Servos embedded into the 3D printed parts allow “Steve” to rotate at the hips and raise and lower his arm. With a fishing pole slipped into a hole printed into the hand, he’s able to cast out his magnetic bobber and see whats biting.
