Day: May 10, 2019

It’s Never Too Early To Prepare For Halloween: With Flamethrowers

May 10, 2019 by 3 Comments

Using a legitimate flamethrower is on the bucket list for a lot of us. Even Elon Musk got into the action with his Not-A-Flamethrower flamethrower. For the rest of us non-billionaires though, we have to come up with clever reasons to build our own like “Halloween is only six months away”. [HandsomeRyan] took this approach six months ago to great effect, and recently released the files on Thingiverse for us all to enjoy.

The cover for building this project was making a Jack-o-Lantern shoot flames out of its face on-demand. The build is based around a car door locking solenoid, which has plenty of kick for applications like this. [HandsomeRyan] upgraded his old wood design with fancy 3D-printed parts which, with the help of the solenoid, deliver a blast of flammable material across a candle inside the Jack-o-Lantern via an aerosol can hidden in the pumpkin.

Part of the elegance of this project is that a car door locking solenoid is typically controlled by remote, meaning that if you want this to be remote-controlled the work has already been done for you. If you need a more timely excuse for building one of these, the Fourth of July is a little bit closer, which should work in a pinch as an excuse to build something crazy even if you’re not American.

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Hacking The Ionosphere, For Science

May 10, 2019 by 14 Comments

Imagine what it must have been like for the first human to witness an aurora. It took a while for our species to migrate from its equatorial birthplace to latitudes where auroras are common, so it was a fairly recent event geologically speaking. Still, that first time seeing the shimmers and ribbons playing across a sky yet to be marred by light pollution must have been terrifying and thrilling, and like other displays of nature’s power, it probably fueled stories of gods and demons. The myths and legends born from ignorance of what an aurora actually represents seem quaint to most of us, but it was as good a model as our ancestors needed to explain the world around them.

Our understanding of auroras needs to be a lot deeper, though, because we now know that they are not only a beautiful atmospheric phenomenon but also a critical component in the colossal electromagnetic system formed by our planet and our star. Understanding how it works is key to everything from long-distance communication to keeping satellites in orbit to long-term weather predictions.

But how exactly does one study an aurora? Something that’s so out of reach and so evanescent seems like it would be hard to study. While it’s not exactly easy science to do, it is possible to directly study auroras, and it involves some interesting technology that actually changes them, somehow making the nocturnal light show even more beautiful.

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Python And Pi Provide Heads Up Display For Your Experimental Airplane

May 10, 2019 by 9 Comments

You shouldn’t be looking at screens when you’re driving, but what about a heads-up display? A screen that could put relevant information in your field of vision would be great, even more so if it used a Raspberry Pi. That’s exactly what [John] did, only he did it with an airplane.

First up, the legality of this build. [John]’s plane is registered as experimental, which, provided you know what you’re doing, is pretty close to ‘anything goes’ as you would want in a manned aircraft. [John] has a sufficient number of hours in his log book, and he’s built a Zenith 701.

For hardware, the hard part of this build is constructing a heads-up display. Fortunately, aftermarket HUDs exist, and [John] is using a Kivic projector, a $200 piece of equipment that’s readily available on Amazon. If you need a HUD for your car, there you go. The software is another thing entirely, with the goal of having the software decoupled from the display and data sources. This is somewhat easy to accomplish with a Raspberry Pi; the display is actually just some minimal text-based blocky graphics built in PyGame. This build is also decoupled from the data sources by building this as a user interface for Stratux, an independent Raspberry Pi-based ADS-B receiver for pilots.

There are several views available with this HUD, with the AHRS + ADS-B providing information on the aircraft’s attitude and altitude, along with a few indicators of the nearest planes. The traffic view expands on the ADS-B data, showing the nearest eight or so aircraft in the air, with a range, bearing, and difference in altitude. There’s a diagnostic window, and since [John]’s plane is a backcountry STOL thingamado that can hover in a strong wind, there’s also a digital version of a norden bombsight. It’s for dropping bags of flour onto a grass strip. You can check out [John]’s entire AirVenture presentation of the build below, with all the code available here.

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Barn Door Tracker Needs No Special Tools

May 10, 2019 by 15 Comments

If you want to take a long exposure photograph, you need a tripod to hold your camera steady. But a tripod won’t help when the ground it’s standing on is moving. That’s exactly the problem [Emvilza] ran into when he wanted to take minutes or hours long photographs of the night sky. His solution was to build a barn door tracker, which he carefully documented in both English and Spanish.

Barn door trackers, also known as scotch mounts have been used by photographers for many years to cancel out the rotation of the earth. This causes stars to appear frozen in the sky and allows for photographs of very dim celestial objects. These trackers range from simple hand-cranked affairs to complex mechanical creations. [Emvilza] decided to have a go at designing and building his own tracker, using only basic tools, as he didn’t have access to a CNC or 3D printer.

The tracker itself is built from wood, with metal hardware. [Emvilza] spent a ton of time designing the tracker using SketchUp. The carefully drawn plans ensured everything would fit together and operate correctly.

One of the toughest parts was accurately bending a threaded rod enough to make it work with the tracker, but not bind the drive system. The mount’s motion comes from a threaded rod. The rod is driven by a stepper motor.  Control and sensing is handled by an ATmega328 programmed using the Arduino toolchain. [Emvilza] learned Eagle and designed a PCB. Rather than etch a board, he simply built the circuit on perfboard, following his layout and traces.

The end result is a tracker that looks and performs great — just check out the images on [Emvilza’s] site to see some examples. Not only that, [Emvilza’s] well written documentation will help anyone looking to build a tracker in the future!