Phased array antenna systems are at the cusp of ubiquity. We now see Multiple-Input Multiple-Output (MIMO) antenna systems on WiFi routers. Soon phased array weather radar systems will help to predict the weather and keep air travel safe, and phased array base stations will be the backbone of 5G which is the next generation of wireless data communication. But what is a phased array antenna system? How do they work? With the help of 1024 LEDs we’ll show you.
Don’t blame us for the click-baity titles in the source articles about this handheld “acoustic tractor beam”. You can see why the popular press tarted this one up a bit, even at the risk of drawing the ire of Star Trek fans everywhere. Even the journal article describing this build slipped the “tractor beam” moniker into their title. No space vessel in distress will be towed by [Asier Marzo]’s tractor beam, unless the aliens are fruit flies piloting nearly weightless expanded polystyrene beads around the galaxy.
That doesn’t detract from the coolness of the build, revealed in the video below. There’s no tutorial per se, but an Instructables post is promised. Still, a reasonably skilled hacker will be able to replicate the results with ease straight from the video. Using mostly off the shelf hardware, [Marzo] creates a bowl-shaped phased array of ultrasonic transducers driven by an Arduino through a DC-DC converter and dual H-bridge driver board to boost the 40 kHz square waves from 5 Vpp to 70 Vpp. By controlling the phasing of the signals, the tractor beam can not only levitate small targets but also move them axially. It looks like a lot of fun.
Acoustic levitation is nothing new here – we’ve covered 3D acoustic airbending, as well as an acoustic flip-dot display. Being able to control the power of sound waves in a handheld unit is a step beyond, though.
Milling machines can be pretty intimidating beasts to work with, what with the power to cut metal and all. Mount a fly cutter in the mill and it seems like the risk factor goes up exponentially. The off-balance cutting edge whirling around seemingly out of control, the long cutting strokes, the huge chips and the smoke – it can be scary stuff. Don’t worry, though – you’ll feel more in control with a shop-built fly cutter rather than a commercial tool.
Proving once again that the main reason to have a home machine shop is to make tools for the home machine shop, [This Old Tony] takes us through all the details of the build in the three-part video journey after the break. It’s only three parts because his mill released the Magic Smoke during filming – turned out to be a bad contactor coil – and because his legion of adoring fans begged for more information after the build was finished. But they’re short videos, and well worth watching if you want to pick up some neat tips, like how to face large stock at an angle, and how to deal with recovering that angle after the spindle dies mid-cut. The addendum has a lot of great tips on calculating the proper speed for a fly cutter, too, and alternatives to the fly cutter for facing large surfaces, like using a boring head.
[ThisOldTony] does make things other than tooling in his shop, but you’ll have to go to his channel to find them, because we haven’t covered too many of those projects here. We did cover his impressive CNC machine build, though. All [Tony]’s stuff is worth watching – plenty to learn.