Day: October 8, 2020

Educational Robot Teaches With Magnets And Servos

October 8, 2020 by 1 Comment

Teaching kids about robotics gives them valuable skills for their futures, and is generally pretty darn fun for all involved, too. However, teaching children often involves taking a bit of a different tack to educating college students, and more of a hand-holding approach is often needed. This robot project is an attempt to do just that, using some classic time-honored techniques and a unique method of propulsion.

The Magnetic Motion Robot, or MMR, is very much a DIY project. Built out of hand-cut plywood and assembled by lacing together individual modules, it’s a low-cost entry into the world of educational robotics. Rather than wheels or motors, it instead uses electromagnets mounted on servo arms to get around. Switching the magnets on and off, and moving the servos in time, allows the robot to pull itself along a ferromagnetic surface.

The robot is outfitted with buzzers and LEDs, and using these features creates further programming challenges for students. Naturally, there’s also a line-following program, which is a great way to begin educating kids about autonomous robot operations. It’s all run from an Arduino Nano, programmed with Makeblock’s special building-block programming software.

While its DIY nature makes assembly a little more involved than the average off-the-shelf kit, it does present its own learning opportunities such as soldering and the integration of hardware. Educational robots will continue to be popular and fun long into the future; we’re a particular fan of sumobots ourselves. Video after the break.

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Current Sensor Makes Intriguing Use Of Concrete

October 8, 2020 by 20 Comments

Getting a product to market isn’t all about making sure that the product does what it’s supposed to. Granted, most of us will spend most of our time focusing on the functionality of our projects and less on the form, fit, or finish of the final product, especially for one-off builds that won’t get replicated. For those builds that do eventually leave the prototyping phase, though, a lot more effort goes into the final design and “feel” of the product than we might otherwise think. For example, this current sensor improves its feel by making use of cast concrete in its case.

The current sensor in this build is not too much out of the ordinary. [kevarek] built the sensor around the MCA1101-50-3 chip and added some extra features to improve its electrostatic discharge resistance and also to improve its electromagnetic compatibility over and above the recommended datasheet specifications. The custom case is where this one small detail popped out at us that we haven’t really seen much of before, though. [kevarek] mixed up a small batch of concrete to pour into the case simply because it feels better to have a weightier final product.

While he doesn’t mention building this current sensor to sell to a wider audience, this is exactly something that a final marketable product might have within itself to improve the way the device feels. Heavier things are associated, perhaps subconsciously, with higher quality, and since PCBs and plastic casings don’t weigh much on their own many manufacturers will add dummy weights to improve the relationship between weight and quality. Even though this modification is entirely separate from the function of the product, it’s not uncommon for small changes in design to have a measurable impact on performance, even when the original product remains unmodified.

Thanks to [Saabman] for the tip!

Light Tracking Robot Relies On LDRs

October 8, 2020 by 26 Comments

These days, when doing any sort of optical tracking, our mind immediately leaps towards sophisticated solutions. Raspberry Pis, high end cameras, and machine learning toolchains all come to mind. Of course, if your goals are simpler, you needn’t complicate the issue. PHIL is a light tracking robot who is perfectly happy to do it the old-school way.

PHIL consists of an Arduino Uno running a twin-servo motion platform, providing the sensor head with pan and tilt functionality. The sensor head itself consists of a 3D-printed cruciform-section shroud that mounts four light-dependent resistors in individual sections. The shroud helps block light to the off-angle sensors, giving a stronger difference between those exposed to the light directly and those on the dark side. This makes for a stronger difference signal, so when the Arduino reads the sensors, it’s much clearer which way PHIL should point the sensor head to follow the light.

The builder, [Sean O’Donovan], notes that PHIL was built with no practical purpose in mind, and is simply a cool project. We certainly agree, and it’s important to note that skills picked up on a project like this will invariably come in handy down the track. Such techniques can be highly useful for tracking the sun, for example. Video after the break.

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A Double Shot Of Vintage Computing This Weekend

October 8, 2020 by 1 Comment

Going anywhere interesting this weekend? No, of course you aren’t. None of us are. So why not tune your computer or smartphone to the online stream of one of the virtual Vintage Computer Festivals that will be taking place between October 10th and 11th. Granted only one of them is in English, but we’ve often thought of blinky lights as something of a universal language anyway.

Vintage Computer Festival East, which normally would have happened in the Spring, has finally decided that 2020 is a wash for any in-person meetings and has decided to switch over to virtual. Interestingly, it sounds like they’ll be live streaming at least some of the exhibitor tables from the InfoAge museum in New Jersey where the physical event would have been held. So from an attendee perspective, the virtual event should be a bit closer to the real thing than if everyone had to figure out their own streaming setups from home. Presentations will run from 9:00 AM to 6:00 PM Eastern on both days.

On the other side of the globe, Vintage Computing Festival Berlin will be broadcasting their own exhibitions, workshops, and lectures. In an interesting use of the virtual format, they’ll be giving viewers an intimate look at vintage computers and technology that’s held in private collections, museums, or otherwise inaccessible storage and research facilities. Content will be streaming from 10:00 AM to 8:00 PM CEST on both days, with a musical performance overnight.

While there’s an understandable tendency to bemoan the trend of moving events online in the face of COVID-19, there are certainly situations where the format can actually bring you more content than you’d have access to otherwise. Especially when they end up being free, as is the case with both of these Festivals. We’re still eagerly awaiting the point where we can get back to attending these events in person, but we certainly aren’t complaining when so many incredible people are willing to put on these presentations without seeing a dime.

OpenFluid Warmer Aims To Get Medical Equipment Where It’s Needed

October 8, 2020 by 7 Comments

Intravenous fluids, or IV fluids, are a vital part of modern life-saving medicine. Depending on the fluids in question, they must often be stored at low temperatures, however, for delivery to a patient, it is beneficial to warm them to approximately 38 degrees to avoid causing hypothermia. To achieve this, an IV fluid warmer is used, but these are not readily available all over the world. To help rectify this shortcoming, [John Opsahl] started the OpenFluidWarmer project.

The goal of the project is to produce a safe, reliable IV fluid warmer that is also easily reproducible. Materials used must be cheap and readily available, and ideally should be easily substitutable where possible to maximise the design’s ability to be built anywhere it’s needed. The name of the project is a nod towards its open design – with the goal of the project to deliver medical equipment to those that don’t have it, there’s little benefit to keeping the design under wraps.

Development continues at a solid pace, with work to optimise the heater performance, firmware, and even the tools required for assembly all documented in the build logs. It’s a project that recalls the scramble earlier this year to create open source ventilators for COVID-19 patients. Ultimately, at the end of the day, it’s about getting medical hardware to where it’s needed most, and we applaud [John]’s efforts in this field! Video after the break.

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Sensing The Earth’s Wobble In Time

October 8, 2020 by 30 Comments

In the 1850s British railway companies started introducing a single standard time to make their timetables consistent. Before that, every city would set its own clock based on the observation of the position of the sun. Nowadays, precise time standards are not only needed so people don’t miss their trains but also make modern communication technologies and satellite navigation work.

Generally, there are two methods of defining time, one is based on the local passage of time as measured by atomic clocks, while the other relies on the exact measurement of Earth’s rotation. The latter is not an easy exercise that involves extragalactic radio sources or huge laser-based gyroscopes. The constant survey of the Earth’s spin tells us that days are constantly getting longer, but surprisingly, severe earthquakes and weather phenomena can also take little discrete bites out of the planet’s supply of rotational kinetic energy.

How do we keep our ultra precisely measured time, the rotation of the Earth, and our position in the heavens in line?

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A Geared Bench Vise To Clamp All The Things

October 8, 2020 by 21 Comments

On the eternal quest of workshop upgrades, [Alexandre Chappel] has combined woodworking and 3D printing to add a versatile 0.5 m wide vise with some clever internals to his workbench.

The challenge with such a wide vise is that it requires two timed lead screws on either end of the vise to prevent if from pulling skew under force. This can be done with a chain, belt, or [Alexandre]’s choice, gears. Inside the moving part of the vise he fitted series of 5 herringbone gears. By turning the center gear with a lever, it rotates the gears on the end which are fixed to tow lead screws. The external surfaces of the clamp are made with plywood, and the gears are printed with PLA and high infill percentage. [Alexandre] does say that he is not sure durable the gears are, but they definitely aren’t flimsy. He added an acrylic inspection window to the box section, which we think looks superb with the colored gears peaking through. The back of the vise is mounted inside the workbench, which keeps the look clean and doesn’t take up any bench space.

[Alexandre] does a lot of filming in his workshop, so recently he also built a very impressive and practical camera arm to avoid having to move tripods the whole time. A vise is a must-have tool in almost any workshop, so we’ve seen a few DIY versions, like magnetic base vise and one with a hydraulic vise.