Tracing In 2D And 3D With Hall Effect Sensors

Pantographs were once used as simple mechanical devices for a range of tasks, including duplicating simple line drawings. [Tim] decided to make a modern electronic version that spits out G-Code instead.

The design relies on a 3D-printed pantograph assembly, mounted upon a board as a base. A pair of Hall effect sensors are mounted in the pantograph, which, along with a series of neodymium magnets, can be used to measure the angles of the pantograph’s joints. The Hall sensors are read by an Arduino Nano, which computes the angles into movement of the pantograph head and records it as G-Code. This can simply be displayed on the attached LCD display, or offloaded to a computer for storage.

[Tim] explains the basic theory behind the work in an earlier piece, where he built a set of electronic dividers using the same techniques. He didn’t stop there, either. He also built a more complex version that works in 3D that he calls it the Electronic Point Mapper, which can be used to generate point clouds with a 3D-capable pantograph mechanism.

It’s a neat way to learn about geometry, and could even be useful if you’re doing some work in tracing 2D drawings or measuring 3D objects.

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Mecanum-Wheeled Robot Chassis Takes Commands From PS4 Controller

Mecanum wheels are popular choices for everything from robots to baggage handling equipment in airports. Depending on their direction of rotation, they can generate forces in any planar direction, providing for great maneuverability. [ATOM] set about building just such a robot chassis, and learned plenty in the process.

The design is similar to those we’ve seen in the past. The robot has four mecanum wheels, each driven by its own motor. Depending on the direction of rotation of the various wheels, the robot can move forward, backwards, and even strafe left and right. Plus, it can effectively tank turn without excessive slippage thanks to the rollers on each wheel. An ESP32 serves as the brains of the ‘bot, allowing it to be readily remote controlled via a PS4 gamepad over Bluetooth.

If you’re looking to build a small robot chassis that’s great at moving about in tight, small spaces, this could be a great project to learn with. All the necessary parts are relatively easily available, and the PCB files can be had on GitHub.

If you like the idea of mecanum wheels but need something bigger, consider starting with a set of hoverboard wheel motors. Continue reading “Mecanum-Wheeled Robot Chassis Takes Commands From PS4 Controller” →

Angled Drill Guide Helps You With Those Tricky Holes

If you’ve ever tried to drill a hole on an angle with a power drill, you’ve probably drilled some pretty shocking holes. To do it right, you really need some mechanical assistance, and this jig from [Kartik_Nandrui] should do the trick.

The device uses a guide that sits on the surface to be drilled, with a pair of angled connectors that fit two wooden dowels. These connect the guide to a corresponding sleeve that fits around the drill body. The sleeve then slides up and down the dowels, allowing the drill to move in a straight line towards the targeted area.

It’s a useful hack, but we can see room for some improvements that would take it to the next level. Having a way to lock the angle of the guide base would be great for accuracy. As it’s 3D printed, it would also be simple to create a version with a curved guide base that could fit over pipes, or other designs to fit complex geometries like roof sheeting or other corrugated materials.

Sometimes the most interesting hacks are the ones that get us thinking about our own potential projects. If you’ve got any creative tool hacks you’ve been brewing up in the lab, be sure to let us know!

Cute NFL Standings Tracker Uses Little Mini Helmets

If you’re a die-hard sports fan, there’s nothing you love more than staying abreast of developments in the league, from top to bottom. [Kiu] had a family member that was big into NFL, so set about building them a remarkably cool ladder tracker.

The tracker displays the NFL league table with a ten-minute delay, thanks to a paid live data feed from MySportsFeeds.com. When an update comes in, miniature helmets representing each team in the competition are moved into the correct order. The helmets sit on little plastic tags that make moving them easy, reliable, and repeatable. Built using parts familiar to the 3D printer world, this tracker relies on steppers and V-rails for linear movement, under the command of an Arduino Nano.

It’s a build that would look great in any games room, and we bet a scaled-up version would look the business in an upmarket sports bar. Let’s be honest – the league’s top quarterbacks will all be fighting to have one of these sooner rather than later. That’s not to say it won’t sting to come home to your team’s helmet scooting down the board after a painful loss!

We’ve seen some other interesting sports tracking projects over the years, too. Video after the break!
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Coils In The Road Could Charge EVs While Driving

One of the primary issues with EVs is that you need to pull over and stop to get a charge. If there isn’t a high-speed DC charger available, this can mean waiting for hours while your battery tops up.

It’s been the major bugbear of electric vehicles since they started hitting the road in real numbers. However, a new wireless charging setup could allow you to juice up on the go.

Electric Highways

Over the years, many proposals have been made to power or charge electric vehicles as they drive down the road. Many are similar to the way we commonly charge phones these days, using inductive power transfer via magnetic coils. The theory is simple. Power is delivered to coils in the roadway, and then picked up via induction by a coil on the moving vehicle.

Taking these ideas from concept into reality is difficult, though. When it comes to charging an electric vehicle, huge power levels are required, in the range of tens to hundreds of kilowatts. And, while a phone can sit neatly on top of a charging pad, EVs typically require a fair bit of ground clearance for safely navigating the road. Plus, since cars move at quite a rapid pace, an inductive charging system that could handle this dynamic condition would require huge numbers of coils buried repeatedly into the road bed. Continue reading “Coils In The Road Could Charge EVs While Driving” →

SquareBoi Is The DIY Game Boy Cart You’ve Always Wanted

Running unofficial code on a Nintendo Game Boy has long been a solved problem. However, you still need a way to get that code onto the handheld console. The Squareboi cartridge promises to do just that, as created by [ALXCO-Hardware].

It’s a well-featured cartridge, with up to 4 MB of ROM storage onboard. It also features a ferromagnetic RAM part for savegame storage, which doesn’t need a battery to hang on to your precious data. It’s designed to be compatible with the vast majority of Game Boy and Game Boy Color games, with efforts made to support the most common mapping schemes. It can be built using entirely through-hole components, and is readily programmable via an Arduino.

For those eager to tinker with code on the Game Boy, diving into the Squareboi is a great way to get closer to the bare metal and understand what’s really going on at the low level. Those interested in building their own can get all the relevant details over on Github.

We’ve seen similar hacks before, too, like the cartridge that brought Wikipedia to the humble Nintendo handheld. If you’ve been whipping up your own Nintendo hacks, be sure to drop us a line!

Halloween Mirror Offers A Mighty Fright

Jump scares are controversial in the horror world, whether you’re talking about movies or video games. You can bring that same irritating thrill into real life, too, with this Halloween mirror from [jasonwinfieldnz].

During the day, or simply when it’s bright inside, the mirror appears normal, like any other. However, behind the special two-way mirrored glass surface is a spooky 3D print, such as a skull or an annoying yellow cartoon character. When the lighting level gets low, everything changes. A light-dependent resistor hooked up to a Digispark detects the change, and then fires up some 5V LEDs to light the scary image, revealing it behind the mirror. Even better, it plays a loud screaming sound with the help of a DFplayer MP3 module.

We’d love to see the concept taken even further, too. It would be quite something if, when a passer-by approached, the room lights suddenly cut out and the mirror activated in its full glory.

We’ve seen some great Halloween builds over the years. If you’re eager to get one out this season, you might wanna get hacking now! Video after the break.

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