I've been working on an under-actuated drone that can fly with only one motor for the last few months. The propeller hub is 3D printed out of PPA-CF and has a hinge, so when the motor accelerates the blades lag behind and one pitches up while the other pitches down. By pulsing the motor torque 300 times a second, timed to the rotor angle, the drone controls its pitch and roll with the same motor that produces its thrust.

Along the way I also built a "poor man's high speed camera" - a camera flash synced to my camera and motor controller, so I could take images of the propeller at precise angles to analyze its behavior.

The mechanical simplicity hides a lot of software. At almost 20,000 RPM, a 0.2 ms control loop is already 20 degrees of rotation late, so I wrote custom firmware for the motor controller to compute the torque pulses on board. The body also slowly spins, so the drone gets its heading from an infrared "lighthouse" beacon in the corner of the room that it sees once per revolution.

The full video explaining how it all works is available on youtube: https://www.youtube.com/watch?v=Ndftcft6XhU

The code and CAD are open source on github: https://github.com/jyjblrd/single-propeller-drone

These massive guyed masts—the tallest structures in the Czech Republic—folded like an accordion during a controlled demolition. The crew used pyrotechnic charges to sever the supporting guy-wires, causing the structures to lose stability and collapse into their own footprint to minimize the impact area.

Hey! We've been working since last year on a In Control: Rocketry, a spaceflight sim where you build the rocket and wire up its control panel yourself. Sensors, inputs, outputs, the whole thing is Turing-complete, so however you want to solve a flight problem, there's a way to do it. It will be available on Steam in 2027.

Real orbital mechanics, a fictional solar system to explore, sandbox mode if you just want to mess around and blow things up!

Feel free to add the game to your wishlist if you want to support the project! See you in space.

^OC https://www.instagram.com/reel/Dehwauox44W/

Had an opportunity to visit this remote wind farm yesterday. Standing directly beneath these massive turbines while they were operating was something else. The sound of those enormous blades cutting through the air was unforgettable.

Quite a remarkable setting for a wind farm!

An interesting video about the Nokia Mechanics Laboratory, which the uploader himself founded.

A 2 × 2 mm BGA, fully fanned out on a single layer, with 50 µm traces running between the pads. PCB fabrication took about 15 minutes, right on my desk. I then assembled it by hand.

Our guaranteed specs are 75 µm traces and 75 µm clearances. This board uses 50 µm traces and clearances down to about 70 µm—a little demonstration of the headroom beyond those specs.

The board also has 1 × 1 mm addressable LEDs with four pads each. PewCB One made the solder-paste stencil too, cutting the openings directly over the PCB pads.

Let me know what you’d like to see tested next.

For more experiments like this and to chat with our team, join our Discord.

More about PewCB One.

This is what rc people in china do for fun

I'm thinking of making this a kickstarter to make these prebuilt cockpits and add them to any rc airplane, just check out my website Longfly.us to let me know if you would like to buy one

And check out more on my instagram @longfly.us