The history of aviation is a fascinating one, spanning more than two thousand years starting from kites and tower jumping. Many hackers are also aviation fans, and the name of Alberto Santos Dumont may be familiar, but if not, here we talk about his role and accomplishments in the field. Santos Dumont is one of the few aviation pioneers that made contributions in both balloons, airships and heavier-than-air aircraft.
When [Zeke Gabrielse] needed to book a flight, the Internet hive-mind recommended that he look into traveling with Southwest airlines due to a drop in fares late Thursday nights. Not one to stay up all night refreshing the web page indefinitely, he opted to write a script to take care of the tedium for him.
Settling on Node.js as his web scraper of choice, numerous avenues of getting the flight pricing failed before he finally had to cobble together a script that would fill out and submit the search form for him. With the numbers coming in, [Grabrielse] set up a Twilio account to text him once fares dropped below a certain price point — because, again, why not automate?
The types of steps and missteps the Wright brothers took in developing the first practical airplane should be familiar to hackers. They started with a simple kite design and painstakingly added only a few features at a time, testing each, and discarding some. The airfoil data they had was wrong and they had to make their own wind tunnel to produce their own data. Unable to find motor manufacturers willing to do a one-off to their specifications, they had to make their own.
Sound familiar? Here’s a trip through the Wright brothers development of the first practical airplane.
Over the course of 10 years, [Bruce Campbell] has built himself a sleek pad out of a Boeing 727-200 in the middle of the picturesque Oregon countryside.
As you’d expect, there are a number of hurdles to setting up a freaking airplane as one’s home in the woods. Foremost among them, [Campbell] paid $100,000 for the aircraft, and a further $100,000 for transportation and installation costs to get it out to his tract of land — that’s a stiff upfront when compared to a down payment on a house and a mortgage. However, [Campbell] asserts that airplanes approaching retirement come up for sale with reasonable frequency, so it’s possible to find something at a lower price considering the cost of dismantling an airframe often compares to the value of the recovered materials.
Once acquired and transported, [Campbell] connected the utilities through the airplane’s existing systems, as well going about modifying the interior to suit his needs — the transparent floor panels are a nice touch! He has a primitive but functional shower, the two lavatories continue to function as intended, sleeping, dining and living quarters, and a deck in the form of the plane’s wing.
We love solar power. Not only is it environmentally friendly, but it’s relatively lightweight and involves fragile high technology. Just the sort of thing that we’d want to strap onto the wings of a large model aircraft.
Solar power on a remote-controlled plane would get you unlimited cruising range. Now, a normal land-and-swap-battery process might be good enough for some people, but judging from [Prometreus]’s YouTube channel, he’s a fan of long flights over the Alps, and of pushing long-distance FPV links to the breaking point. For him and his friends, the battery power is definitely the limiting factor in how far / long he can fly.
All of the information we have is in the video, but that’s plenty. [Prometreus] didn’t bother with maximum-power-point tracking, but instead wired up his solar cells to work just about right for the voltage of his batteries and the level of sun that he’s seeing. So it won’t work nearly as well on cloudy days. (Check out this MPPT build that was submitted for the Hackaday Prize.)
He could switch the solar cells in an out remotely, and it’s pretty gratifying to see the consumed current in the battery go down below zero. In the end, he lands with a full battery. How cool is that?
We’ve probably all experimented with a very clear demonstration of the basic principles of lift: if you’re riding in a car and you put your flattened hand out the window at different angles, your hand will rise and fall like an airplane’s wing, or airfoil. This week’s Retrotechtacular explains exactly how flight is possible through the principles of lift and drag. It’s an Army training documentary from 1941 titled “Aerodynamics: Forces Acting on an Air Foil“.
What is an airfoil? Contextually speaking, it’s the shape of an airplane’s wing. In the face of pressure differences acting upon their surfaces, airfoils produce a useful aerodynamic reaction, such as the lift that makes flight possible. As the film explains, the ideas of lift and drag are measured against the yardstick of relative wind. The force of this wind on the airfoil changes according to the acute angle formed between the airfoil and the direction of the air flow acting upon it. As you may already know, lift is measured at right angles to the relative wind, and drag occurs parallel to it. Lift is opposed by the weight of the foil, and drag by tension.
Airfoils come in several types of thicknesses and curvatures, and the film shows how a chord is derived from each shape. These chords are used to measure and describe the angle of attack in relation to the relative wind.
The forces that act upon an airfoil are measured in wind tunnels which provide straight and predictable airflow. A model airplane is supported by wires that lead to scales. These scales measure drag as well as front and rear lift.
In experimenting with angles of attack, lift and drag increase toward what is known as the stalling angle. After this point, lift decreases abruptly, and drag takes over. Lift and drag are proportional to the area of the wing, the relative wind velocity squared, and the air density. When a plane is in the air, drag is a retarding force that equals the thrust of the craft, or the propelling force.
Airfoil models are also unit tested in wind tunnels. They are built with small tubes running along many points of the foil that sit just under the surface. The tubes leave the model at a single point and are connected to a bank of manometer tubes. These tubes compare the pressures acting on the airfoil model to the reference point of atmospheric pressure. The different liquid levels in the manometer tubes give clear proof of the pressure values along the airfoil. These levels are photographed and mapped to a pressure curve. Now, a diagram can be made to show the positive and negative pressures relative to the angle of attack.
In closing, we are shown the effects of a dive on lift as an aircraft approaches and reaches terminal velocity, and that lift is attained again by pulling slowly out of the dive. Remember that the next time you fly your hand-plane out the window.
Quadcopters are a ton of fun to play with, and even more fun to build. [Vegard] wrote in to tell us about his amazing custom DIY quadcopter frame that uses a commercial flight control system.
Building a quadcopter is the perfect project to embark upon if you want to test out your new CNC mill and 3D printer. The mechanical systems are fairly simple, yet result in something unbelievably rewarding. With a total build time of 30 hours (including Sketchup modeling), the project is very manageable for weekend hackers. [Vegard’s] post includes his build log as well as some hard learned lessons. There are also tons of pictures of the build. Be sure to read to read the end of the post, [Vegard] discusses why to “never trust a quadcopter” and other very useful information. See it in action after the break.
While the project was a great success, it sadly only had about 25 hours of flight-time before a fatal bird-strike resulted in quite a bit of damage. Have any of your quadcopters had a tragic run-in with another flying object? Let us know in the comments.