Robust Water-Rocket Launcher Gets The Engineering Just Right

Normally when we run across a project that claims to be overengineered, we admit that we get a little excited. Such projects always hold the potential for entertainingly over-the-top designs, materials, and methods. In this case, though, we’ll respectfully disagree with [Zach Hipps] assessment of his remote-controlled soda bottle rocket launcher as “overengineered”. To us, it seems just right.

That’s not to take away from anything accomplished with this build. Indeed, we’re mighty impressed by the completeness of the build, which was intended to create a station for charging and launching air-powered water rockets. The process started with a prototype, built mainly from 3D-printed parts but with a fair selection of workshop scraps to hold it together. This allowed [Zach] to test the geometry of the parts, operation of the mechanism, and how it interfaced with the flange on the necks of 2-liter soda bottles.

Honestly, the prototype was pretty good by itself and is probably where many of us would have stopped, but [Zach] kept going. He turned most of the printed parts into machined aluminum and Delrin, making for a very robust pneumatically operated stand. We’ve got to say the force with which the jaws close around the bottle flange is a bit scary — looks like it could easily clip off a wayward finger. But if he manages to avoid that fate, such a hearty rig should keep [Zach] flying for a long time. Perhaps it could even launch a two-stage water rocket?

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Linux Fu: Monitor Disks

If you want a quick view of a Linux system’s process load, you can use top or — slightly nicer — htop. But what if you want a quick snapshot of how the disk system is doing? There are a few tools you can use, some of which are not nearly as common as top.

First, iotop

Most similar to top is iotop. This program shows you the total and current disk read and write numbers for the file system and also shows you who is eating up the most disk I/O.  This screen looks busy:

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Quadcopter With Tensegrity Shell Takes A Beating And Gets Back Up

Many of us have become familiar with the distinctive sound of multirotor toys, a sound frequently punctuated by sharp sounds of crashes. We’d then have to pick it up and repair any damage before flying fun can resume. This is fine for a toy, but autonomous fliers will need to shake it off and get back to work without human intervention. [Zha et al.] of UC Berkeley’s HiPeRLab have invented a resilient design to do so.

We’ve seen increased durability from flexible frames, but that left the propellers largely exposed. Protective bumpers and cages are not new, either, but this icosahedron (twenty sided) tensegrity structure is far more durable than the norm. Tests verified it can survive impact with a concrete wall at speed of 6.5 meters per second. Tensegrity is a lot of fun to play with, letting us build intuition-defying structures and here tensegrity elements dissipate impact energy, preventing damage to fragile components like propellers and electronics.

But surviving an impact and falling to the ground in one piece is not enough. For independent operation, it needs to be able to get itself back in the air. Fortunately the brains of this quadcopter has been taught the geometry of an icosahedron. Starting from the face it landed on, it can autonomously devise a plan to flip itself upright by applying bursts of power to select propeller motors. Rotating itself face by face, working its way to an upright orientation for takeoff, at which point it is back in business.

We have a long way to go before autonomous drone robots can operate safely and reliably. Right now the easy answer is to fly slowly, but that also drastically cuts into efficiency and effectiveness. Having flying robots that are resilient against flying mistakes at speed, and can also recover from those mistakes, will be very useful in exploration of aerial autonomy.

[IROS 2020 Presentation video (duration 14:16) requires free registration, available until at least Nov. 25th 2020. One-minute summary embedded below]

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Rebuilding A Hero (the Robot, Not The Sandwich)

When [Scott Baker] found a Heathkit Hero Junior on eBay, he grabbed it. He had one as a kid, but it was long sold. The robot arrived with no electronics, so the first order of business is to give it some new modern brains including an ATMega328 and a Raspberry Pi. You can see the start of the project in the video below.

So far, you can see a nice teardown of the chassis and what’s left of the little robot’s drive system. This wasn’t the big Hero-1 that you probably remember, but it was still a pretty solid platform, especially for the time it was on the market.

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DualShock Flight Simulator Yoke

Aircraft control interfaces can be divided into stick or yoke, with the stick being more popular for flight simulators. [Akaki Kuumeri] has been designing some ingenious 3D printed adaptors for game console controllers, and his latest build is a yoke adaptor for the PlayStation DualShock Controller.

Like his previous joystick/throttle combination, this yoke makes use of a series of ball and socket links to convert the yoke’s push/pull and rotation motion into the appropriate inputs on the controller’s thumbs sticks. All the components are 3D printed except for rubber bands to provide spring tension. On the sliding contact surfaces between the different components, [Akaki] specifically designed the parts to slide along the grain (layer lines) to allow for smooth motion without resorting to bearings.

If you want an absolute minimalist yoke, tape some potentiometers to a desk drawer. Or you can go to the other end of the scale and build a complete cockpit. With the arrival of Microsoft Flight Simulator 2020, we’ll be seeing a lot of controller builds.

Building Walks With Robot Legs

The Shanghai Evolution Shift company has just pulled off one of the most impressive robotic projects we’ve ever seen – making a building walk using 198 robotic legs. We’ve all seen structural relocation documentaries where large buildings are moved to new locations. This involves jacking up the building and installing a supporting platform on wheels, then carefully towing the building to its new site.

But the T shape of the five story, 7600 ton Lagena elementary school was problematic, and the route to the new site involved taking a curved path and rotating the building. This ruled out the more traditional methods of relocation. Robot legs came to the rescue. It took 18 days for the building to walk 62 meters and rotate 21 degrees to its new home. This project is part of a trend to preserve historic architecture rather than bulldoze everything to make space for modern buildings.

After watching the video below, we think you’ll agree that this is a unique application of robotics and an amazing engineering feat. Disclaimer – don’t try this at home. Thanks to [Chuckz] for sending us this tip.

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3D Printed Workshop Lamp Uses A Few Neat Tricks

As far as light fittings go, store bought is fine, but it’s hard to beat something you’ve built yourself from the ground up. [Heliox] demonstrates this well, with a 3D-printed workshop lamp that looks the business and is functional, too.

The lamp has plenty of neat design touches that speak to [Heliox]’s experience in the 3D printed arts. The articulating arms are modular, and feature integrated cable guides. The lamp base features nuts inserted mid-print for easy assembly, and the swivel is actually a two-piece mechanism printed as a single assembly. The table clamp uses a large screw, and the benefit of 3D printing means its easy to customise to suit any individual table. Using black and orange filaments gives the lamp a proper industrial look, and the bright LED strips are perfect for illuminating a bench for fine detailed work.

It’s a great addition to [Heliox]’s workspace, and the tall articulated design means it can cast light without getting in the way of what you’re doing. We’ve featured her work before, too – like this glorious infinity cube. Video after the break.

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