How To Get Into Cars: Handling Mods

March 10, 2020 by 31 Comments

As a budding automotive enthusiast, you finally took the plunge and scored yourself a sweet project car. After going through it from top to toe, you’ve done your basic maintenance and it’s now running like a top. Now you’re getting comfortable, you’ve set your sights on turning your humble ride into a corner carving machine. Here’s a guide to get yourself started.

It’s All About Grip

When it comes to creating a handling monster, the aim is to create a car that sticks to the road like glue, and is controllable when it does break loose. Having a car that handles predictably at the limit is a big help when you’re pushing hard on track, particularly for an inexperienced driver. And, whether you’re hitting the canyons on the weekend or trying to slash your laptimes, it’s always nice to have more grip. Through selecting the right parts and getting the set up right, it’s possible to hone your car’s cornering ability to make it a rewarding experience to drive fast and hard. Continue reading “How To Get Into Cars: Handling Mods” →

Solar Panel Keeps Car Battery Topped Off Through OBD-II Port

March 10, 2020 by 47 Comments

Up until the 1980s or so, a mechanic could check for shorts in a car’s electrical system by looking for sparks while removing the battery terminal with everything turned off in the car. That stopped being possible when cars started getting always-on devices, and as [Kerry Wong] learned, these phantom loads can leave one stranded with a dead battery at the airport after returning from a long trip.

[Kerry]’s solution is simple: a solar trickle charger. Such devices are readily available commercially, of course, and generally consist of a small photovoltaic array that sits on the dashboard and a plug for the lighter socket. But as [Kerry] points out in the video below, most newer model cars no longer have lighter sockets that are wired to work without the ignition being on. So he chose to connect his solar panel directly to the OBD-II port, the spec for which calls for an always-on, fused circuit connected directly to the positive terminal of the vehicle battery. He had to hack together an adapter for the panel’s lighter plug, the insides of which are more than a little scary, and for good measure, he added a Schottky diode to prevent battery discharge through the panel. Even the weak winter sun provides 150 mA or so of trickle charge, and [Kerry] can rest assured his ride will be ready at the end of his trip.

We used to seeing [Kerry] tear down test gear and analyze unusual devices, along with the odd post mortem on nearly catastrophic failures. We’re glad nothing burst into flames with this one.

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The Best Voltage And Current Reference This Side Of A Test Lab

March 10, 2020 by 16 Comments

When you measure a voltage, how do you know that your measurement is correct? Because your multimeter says so, of course! But how can you trust your multimeter to give the right reading? Calibration of instruments is something we often trust blindly without really thinking about, but it’s not always an impossible task only for a high-end test lab. [Petteri Aimonen] had enough need for a calibrated current source to have designed his own, and he’s shared the resulting project for all to see.

The cost of a reference source goes up with the degree of accuracy required, and can stretch into the many millions of dollars if you are seeking the standards of a national metrology institute, but fortunately [Petteri]’s requirements were considerably more modest. 0.02% accuracy would suffice. An Analog Devices precision voltage reference driving a low-offset op-amp with a driver transistor supplies current to a 0.01% precision resistor, resulting in a reference current source fit for his needs. The reference is available in a range of voltages, his chosen 2.048 volts gave a 2.048 mA current sink with a 100 ohm resistor.

In a way it is a miracle of technology that the cheapest digital multimeter on the market can still have a surprisingly good level of calibration thanks to its on-chip bandgap voltage reference, but it never hurts to have a means to check your instruments. Some of us still rather like analogue multimeters, but beware — calibration at the cheaper end of that market can sometimes be lacking.

Divvy Out The Crypto With This Physical Bitcoin Faucet

March 9, 2020 by 3 Comments

For those unfamiliar with the term, a “Bitcoin Faucet” is usually used as an incentive in software that wants your attention. Complete a captcha or look at and advertisement and you get one millionth of a BTC, that sort of thing. You’re never going to get rich off of one of them, but most people aren’t going to turn down free money either. The latest project from [TJ Bruno] follows that same concept and brings it into the physical world. But you still aren’t going to get rich off of it.

The hardware used for this corporeal Bitcoin Faucet is pretty simple. All you need is a Raspberry Pi, a camera module, and a 2.8″ touch LCD. Naturally you could use a larger screen if you wanted, but then it wouldn’t fit inside of the very slick 3D printed stand that [TJ] developed. We might consider upgrading to a slightly speedier Pi though, in the demonstration video it looks like the Zero is struggling pretty hard to handle the GUI.

Using the Faucet is straightforward enough. You tap the screen and place a QR code representing your Bitcoin wallet on the device’s tray, where it’s scanned by the camera. In a few seconds the Faucet shows a QR code on its own screen that will point your phone’s browser to the transaction details so you can verify your digital coinage is on the way.

You might be wondering why you’d want to have a device that sits there waiting to pay out fractions of a BTC to anyone who’s willing to flash their wallet at it. We’re not entirely sure, though it might make for an interesting way to raise awareness about cryptocurrency. In this particular case though, [TJ] says he was just looking for a project that would give him an excuse to hone his Python skills. Nothing wrong with that around these parts.

Watching the growth of cryptocurrency from our unique vantage point, we can see how the hacker’s interest in Bitcoin as changed over the years. Where we once saw people excited about building custom mining rigs, we now see counters that tick down as the last coins are put into circulation. Looking at projects like this, it seems hackers are happy enough to just give the things away in an interesting way.

A Reminder Not To Touch Your Face

March 9, 2020 by 16 Comments

In 2020, the world is focused on the rampant spread of a new virus by the name of COVID-19. Like many infectious diseases, transmission can be reduced by good hygiene practices. To help in the fight, [Nick Bild] threw together a device he calls Sentinel.

The concept is simple. Reduce the user touching their own face by shining a warning light when such behaviour is detected. This is achieved through the use of an Arduino, which controls an LED through feedback from an ultrasonic proximity sensor. The LED is placed in the user’s peripheral vision, glowing when the sensor detects hands (or other objects) approaching the face.

While it’s unlikely to be rolled out en-masse, it’s a project that nevertheless reminds us to practice good self-care routines. And, as the adage goes, prevention is better than cure. As governments and industry grapple with the ongoing problem, consider how your supply chain may be exposed to the crisis. Video after the break.

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3D Printed Tooling Punches Above Its Weight With Added Hardware

March 9, 2020 by 18 Comments

Reddit user [thetelltalehart] has been making brake press tooling with 3D printed PLA, and recently shared an interesting picture of a hybrid brake press punch, shown here on the right, in blue.

Printed in PLA, with 80% infill and 12 walls, the tool (right) failed at 5 tons.

In a press, material such as sheet metal is formed into a shape by forcing the material around the tooling. Some types of tooling can be 3D printed, and it turns out that printed tools are not only fast and economical, but can be surprisingly resilient. You can see such tools in action in our earlier coverage of this approach here and here.

[Thetelltalehart]’s previous work was printed at 80% infill and 12 walls, and failed at 5 tons. The new hybrid tool adds some common hardware that has the effect of reinforcing the tool for very little added expense or complexity. The new tool made it up to 7 tons before failure. It’s a clever idea, and an apparently effective one.

The goal with these 3D printed tools is twofold: doing short-run work, and reducing costly rework when developing “real” tooling. Having to re-cut a tool because it isn’t quite right in some way is expensive and costly, and it’s much easier and cheaper to go through that process with 3D printing instead of metal.

Wood-Turning A Bladeless Fan

March 9, 2020 by 15 Comments

It’s a simple enough premise: to make a Dyson-style bladeless fan out of wood. The execution of the finished fan, done and filmed by [Neil] from Pask Makes on YouTube, is however spectacular. Using nothing but scrap wood from a chopping board business local to him, he’s made the entire body of the fan using some interesting fabrication methods.

To plan the circular design of the body, [Neil] used an online calculator to measure the specific cuts of wood he needed in order to form cylinders out of trapezoidal sections glued together. Once the rough shape is made, he then used a profile template to turn the air channel with precision out of the two main parts of the fan body. Then, he uses SketchUp in order to figure out what shape needs to be cut from the base in order for the top to fit on it. From there, it’s just a matter of drilling out slots for the air intake, which he does so with an ingenious custom jig, and fitting the internals of a standard fan into the new wooden body.

The video, which you should definitely watch after the break if you have a spare half hour, might not be detailed enough to be used as a tutorial, but it certainly outlines his methods and the tools used well enough to impress us. And the finished build is beautiful to look at, too! If you’re looking for more impressive woodworking, we’ve covered this gorgeous recreation of a Commodore 64 case in wood. But if the hand-built nature of that doesn’t satisfy you, here’s a professional-looking custom caliper case made with CNC and laser engraving.

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