The Evolution Of A 3D Printed Off-Road R/C Car

April 9, 2020 by 13 Comments

For about as long as hackers and makers have been using desktop 3D printers, there have been critics that say the plastic parts they produce aren’t good for much else than toys and decorative pieces. They claim that printed parts are far too fragile to be of any practical use, and are better suited as prototype placeholders until the real parts can be injection molded or milled. Sure. Try telling that to [Engineering Nonsense].

He recently wrote in (as did a few other people, incidentally) to share the latest version of his incredible 3D printed remote control car, and seeing it tearing around in the video after the break, “fragile” certainly isn’t a word we’d use to describe it. Though it didn’t get that way overnight. The Tarmo4 represents a year of development, and as the name suggests, is the fourth version of the design.

We know the purists out there will complain that the car isn’t entirely 3D printed, but honestly, it’s hard to imagine you could get much closer than this. Outside of the electronics, fasteners, tires, and shocks, the Tarmo4 is all plastic. That includes the gearbox and drive shafts. [Engineering Nonsense] even mentions in the video that he’s not happy with the tires he’s found on the market, and that they too will likely get replaced with printed versions in the future.

While the car is certainly an incredible technical achievement, what’s perhaps just as impressive is the community that’s developed around it in such a relatively short time. Towards the end of the video he shows off a number of custom builds based on previous iterations of the Tarmo. We’re sure that interest from the community has played a part in pushing the design forward, and it’s always good to see a one-off project become something bigger. Hopefully we’ll be seeing even more from this passionate community in the near future.

Just like the Open R/C Project, Tarmo proves that 3D printed parts are more than a novelty. If these diminutive powerhouses can run with printed gears and drive shafts, then you shouldn’t have anything to worry about when you run off the parts for your next project.

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A Gambler’s Bottle Opener

April 9, 2020 by 12 Comments

People can certainly become creative when it comes to completing simple tasks like that of removing a bottle cap. Woodworker [Matt Thompson] has come up with a next-level bottle opener that not only does the job but also functions as a game of chance. (Video, embedded below.)

The process usually starts with a spin of his chore wheel that will surprisingly often advise you to drink a beer. While the bottle cap is removed by a standard wall-mounted opener, the fun starts when the cap falls through a wooden labyrinth of various mechanisms reminiscent of a Rube Goldberg machine. Finally, the cap goes through an arrangement of nails, known as a Galton Board which is also found in some pinball and historic gaming machines, before landing in one of two containers marked “winner” and “try again”. The former will trigger the rotating wheel of a self-built peanut dispenser to provide the thirsty person with some tasty snacks. While we would love to see a making-of video with more technical details of this project, we still appreciate the exquisite woodworking and fine craftsmanship that went into building it.

By the way, if you are ever in need of an Arduino board that can also serve as a bottle opener then have a look at HaDuino.

[Thanks to Emanuel for pointing out the proper name of the Galton Board]

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No Windshield? No Problem, Says McLaren

April 9, 2020 by 79 Comments

All the best sports cars look like they’re moving when they’re just sitting there, and the lines on McLaren’s newest limited-edition plaything redefine that look of speed standing still. Maybe it’s the sneering headlights or the streamlined, reverse-1966 Batmobile styling. Whatever it is, the 804-horsepower two-seater project Elva looks like it’s leaping off the line into the future.

But this future is free from the last thing we’d expect to see removed from any vehicle, especially a $1.7 million supercar — the windshield. Now that the headphone jack has been deemed expendable, it seems that nothing is sacred. The Elva is already a permanent convertible with no windows.

Though McLaren didn’t start this weird and windowless fire, the Elva is meant to fan the flames of futurism. She joins the ranks of a few windshield-free models from Ferrari, Mercedes-Benz, and Aston Martin. In the other guy’s cars, you’ll need a helmet above 30MPH unless you love the thunderous sounds of air buffeting and blown-out hair. It’s a young idea with a few bugs to work out.

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Ultrasonic Sensor Helps You Enforce Social Distancing

April 9, 2020 by 22 Comments

If you’re going outside (only for essential grocery runs, we hope) and you’re having trouble measuring the whole six feet apart from other people deal by eye, then [Guido Bonelli] has a solution for you. With a standard old HC-SR04 ultrasonic sensor, an audio module and a servo to drive a custom gauge needle he’s made a device which can warn people around you if they’re too close for comfort.

As simple as this project may sound like for anyone who has a bunch of these little Arduino-compatible modules lying around and has probably made something similar to this in their spare time, there’s one key component that gives it an extra bit of polish. [Guido] found out how intermittent the reliability of the ultrasonic sensor was and came up with a clever way to smooth out its output in order to get more accurate readings from it, using a bubble sort algorithm with a twist. Thirteen data points are collected from the sensor, then they are sorted in order to find a temporal middle point, and the three data points at the center of that sort get averaged into the final output. Maybe not necessarily something with scientific accuracy, but exactly the kind of workaround we expect around these parts!

Projects like these to help us enforce measures to slow the spread of the virus are probably a good bet to keep ourselves busy tinkering in our labs, like these sunglasses which help you remember not to touch your face. Make sure to check out this one in action after the break!

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What Does A Dependable Open Source Ventilator Look Like?

April 9, 2020 by 61 Comments

Ventilators are key in the treating the most dire cases of coronavirus. The exponential growth of infections, and the number of patients in respiratory distress, has outpaced the number of available ventilators. In times of crisis, everyone looks for ways they can help, and one of the ways the hardware community has responded is in work toward a ventilator design that can be rapidly manufactured to meet the need.

The difficult truth is that the complexity of ventilator features needed to treat the sickest patients makes a bootstrapped design incredibly difficult, and I believe impossible to achieve in quantity on this timeline. Still, a well-engineered and clinically approved open source ventilator might deliver many benefits beyond the current crisis. Let’s take a look at some of the efforts we’ve been seeing recently and what it would take to pull together a complete design.

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Decentralized Privacy-Preserving Proximity Tracing

April 9, 2020 by 6 Comments

As we continue through the pandemic, whether we are on lockdown or still at work, there is a chance for all of us that we could still pick up the virus from a stray contact. Mapping these infections and tracing those in proximity to patients can present a major problem to infection control authorities, and there have been a variety of proposals for smartphone apps designed to track users’ contacts via the Bluetooth identities their phones encounter. This is a particular concern to privacy advocates, because there is a chance that some governments could use this as an excuse to bring in intrusive personal surveillance by this means. A group of academics from institutions across Europe have come together with a proposal for a decentralised proximity tracing system that allows identification of infection risk without compromising the privacy of those using it.

Where a privacy-intrusive system might use a back-end database tracking all users and recording their locations and interactions, this one uses anonymised tokens stored at the local level rather than at the central server. When a user is infected this is entered at app level rather than at server level, and the centralised part of the system merely distributes the anonymised tokens to the clients. The computation of whether contact has been made with an infected person is thus made on the client, meaning that the operator has no opportunity to collect surveillance data. After the pandemic has passed the system will evaporate as people stop using it, rather than remaining in place harvesting details from installed apps. They are certainly not the first academics to wrestle with this thorny issue, but they seem to have ventured further into the mechanics of it all.

As with all new systems, it’s probably good to subject it to significant scrutiny before deploying it live. Have a read. What do you think?

We are all watching our authorities as they race to respond to the pandemic in an effective manner, and we hope that should they opt for an app that it does an effective job and they resist the temptation to make it too intrusive. Our best course of action meanwhile as the general public is to fully observe all advised public health measures such as self-isolation or the wearing of appropriate personal protective equipment.

Adding RGB To A CRT

April 9, 2020 by 30 Comments

There was a time when all TVs came with only an antenna socket on their backs, and bringing any form of video input to them meant dicing with live-chassis power supplies. Then sets with switch-mode supplies made delving into a CRT TV much safer, and we could bodge in composite video and even RGB sockets by tapping into their circuitry. For Europeans the arrival of the SCART socket gave us ready-made connectivity, but in the rest of the world there was still a need to break out the soldering iron for an RGB input. [Jacques Gagnon] is in Canada, and has treated us to a bit of old-school TV input hacking as he put an RGB socket on his JVC CRT set.

Earlier hacks had inventive incursions into discrete analogue circuitry, but on later sets such as this one the trick was to take advantage of the on-screen-display features. The signal processing chip would usually have an RGB input with a blanking input to turn of the picture during the OSD chip’s output. These could be readily hijacked to provide an RGB input, and this is the course taken here. We see a VGA socket on the rear panel going to a resistor network on a piece of protoboard stuck in a vacant space on the PCB, from which a set of lines then go to the signal processing chip. The result is a CRT gaming monitor for retro consoles, of the highest quality.

For those of us who cut our teeth on CRT TVs it’s always good to see a bit of TV hacking. It’s a mod we’ve seen before, too.