If you're trying to detect the orientation of an object, sometimes you really don't need a 6DOF gyro and accelerometer. Hell, if you only need to detect if an object is tilted, you can get a simple "ball in a tube" tilt sensor for pennies. [tamberg] liked this idea, but he required a tilt sensor that works in the X, Y, and Z axes. Expanding on the 'ball in a tube' construction of simple tilt sensors, he designed a laser cut 3D tilt sensor that does all the work of of a $30 IMU.
The basic design of this tilt sensor is pretty simple – just an octahedron with four nails serving as switch contacts at each vertex. An aluminum ball knocks around inside this contraption, closing the nail head switches depending on what orientation it's in. Simple, and the three dimensional version of a ball in tube tilt sensor.
To get the tilt data to the outside world, [tamberg] is using an Adafruit Bluetooth module, with two of the nails in each corner connected to a pin. With just a little bit of code, this 3D tilt sensor becomes a six-way switch to control an RGB LED. Video of that below.
It's summer. It's hot. After [Alex Shure] tried his hand at making his own ice cream, he knew he had to take it a step farther. Introducing icenBerg. He's not just in the ice cream business. He's building an empire.
The salvaged compressor system from the mini fridge provides the cooling for the machine. In his first attempt, he found a power drill wasn't quite strong enough — so he ended up chucking the entire thing into his lathe for unbeatable ice cream mixing. The flavor of choice was apple banana coconut sorbet with chocolate oak cookie chunks and roasted soybeans (say that 10 times fast!).
The machine is far from complete, but as a proof of concept deliciousness it has spurred him to make it even better. He plans on making it a standalone unit using a windshield wiper motor, a PWM circuit with a microcontroller, and even hopes to correlate motor current to ice cream consistency.
Planes these days are super complicated – think about the recent flaming-lithium battery issues in the B787 that may or may not have been solved – but it wasn't always this way. Here's a great example. The manufacture of a Piper J-3 Cub shows simple and efficient mechanical design brought to life in a multitude of steps all performed without automation.
The build starts with the frame. Pipes are nibbled into specialized fish mouths for a tight fit before being strapped to a jig and tack welded. With the fuselage in one piece the frame is removed for each joint to be fully welded and subsequently inspected. Cables are run through the frame to connect control surfaces to the cockpit. Continuing through to wing assembly we were especially surprised to see hand hammering of nails to secure the wood ribs to metal spars. How many nails do you think that worker pounded in a career? The entire aircraft is covered in fabric, an engine is added, and it's into the wild blue yonder.
The look back at manufacturing techniques is interesting — do you think the large model shown in the video would be built these days, or would they just use a CAD rendering?