Misc Hacks

4032 Articles

Cheap Lab Balance Needs Upgrades, Gets Gutted Instead

June 12, 2020 by 29 Comments

What is this world coming to when you spend seven bucks on a digital scale and you have to completely rebuild it to get the functionality you need? Is nothing sacred anymore?

Such were the straits [Jana Marie] found herself in with his AliExpress special, a portable digital scale that certainly looks like it’s capable of its basic task. Sadly, though, [Jana] was looking for a few more digits of resolution and a lot more in the way of hackability. And so literally almost every original component was ripped out of the scale, replaced by a custom PCB carrying an STM32 microcontroller and OLED display. The PCB has a complicated shape that allows the original lid to attach to it, as well as the stainless steel pan and load cell. [Jana] developed new firmware that fixes some annoying traits, for example powering down after 30 seconds, and adds new functionality, such as piece-counting by weight. The video below shows some of the new features in action.

Alas, [Jana] reports that even the original load cell must go, as it lacks the accuracy her application requires. So she’ll essentially end up building the scale from scratch, which we respect, of course. At this rate, she might even try to build her own load cell from SMD resistors too.

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Now This Is A Maker’s PCB Shaker

June 12, 2020 by 33 Comments

Anyone who has ever etched their own PCB knows that the waiting is the hardest part. Dissolving copper in ferric chloride takes time, much like developing a Polaroid picture. And although you really should not shake a fresh Polaroid to speed up development, the PCB etching process thrives on agitation. Why wait an hour when you can build a simple PCB shaker and move on to drilling and/or filling in 10 minutes?

We love that [ASCAS] was probably able to build this without reaching past the the spare parts box and the recycling bin. There’s no Arduino or even a 555 — just a 12 VDC geared motor, a DC-DC buck converter, and an externalized pot to control the speed of the sloshing.

It’s hard to choose a favorite hack here between the hinge used to rock this electric seesaw and the crankshaft/armature [ASCAS] made from a sandwich spread lid and a Popsicle stick. Everything about this build is beautiful, including the build video after the break.

Did you know that unlike ferric chloride, copper chloride can be recharged and reused? Here’s a one-stop etching station that does just that.

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Contactless Doorbell Built To Avoid Coronavirus

June 4, 2020 by 15 Comments

It’s often said that necessity breeds creativity, and during a global pandemic such words have proved truer than ever. Realising the common doorbell could be a potential surface transmission point for coronavirus, [CasperHuang] whipped up a quick build.

The build eschews the typical pushbutton we’re all familiar with. Instead, it relies on an ultrasonic distance sensor to detect a hand (or foot) waved in front of the door. An Arduino Leonardo runs the show, sounding a buzzer when the ultrasonic sensor is triggered. In order to avoid modifying the apartment door, the build is housed in a pair of cardboard boxes, taped to the base of the door, with wires passing underneath.

It’s a tidy way to handle contactless deliveries. We imagine little touches like this may become far more common in future design, as the world learns lessons from the COVID-19 pandemic. Every little bit helps, after all. Video after the break.

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Scientific Calculator Whipped Up In Python

June 2, 2020 by 31 Comments

Scientific calculators were invaluable to most of us through high school and college, freeing us from the yoke of using tables to calculate logarithms and trigonometric functions. Once out in the real world, it’s no longer necessary to use an education board approved device to do your maths – you can do it all on your PC instead. For those keen to do so, [AstusRush]’s latest Python work may be just the ticket!

Far exceeding the capabilities of the usual calculator apps, there’s plenty of useful features under the hood. Particularly exciting is the LaTeX display, which shows equations in textbook-quality human-readable format. There’s also a graphing suite, and capability to handle matricies and vectors. LAN chat is implemented too, useful for working in teams.

It’s a useful tool that may suit better than a full-fat MATLAB install, particularly at the low, low price of free. This is one calculator that CASIO will have to keep their nose out of!

A Tasty Output Device

May 30, 2020 by 11 Comments

We have headphones for your ears, and monitors for your eyes. Some computers even have tactile feedback. Now researchers have an output device for taste. The decidedly odd device uses five gels, one for each of the tastes humans can sense. If we understand the paper, the trick is that ionizing the gels inhibits the taste of that gel. By controlling the ionization level of each gel, you can synthesize any taste, just like you can make colors with three LEDs.

The five gels are made from agar and glycine (sweet), magnesium chloride (bitter), citric acid (acidic), salt (salty), and glutamic sodium (umami). If you didn’t learn about umami in school, that’s a savory taste likened to the taste of a broth or meat and often associated with monosodium glutamate.

The shape of the device is made like a sushi roll so that while the gels contact the tongue, a copper foil cathode can connect also. Using this will make you look even stranger than someone wearing Google Glass, but that’s the price of being on the cutting edge of technology, we suppose. There doesn’t seem to be any reason you couldn’t duplicate something like this, although we wonder about the hygiene of passing it around at parties. Maybe your next home movie could show a meal and let the viewer taste it too.

If you are wondering about smell, that’s another set of researchers. You would think this is the first taste output device we have seen, but no… surprisingly, it isn’t.

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Steampunk Brushless Motor Demo Pushes All The Maker Buttons

May 29, 2020 by 46 Comments

We’ll be honest right up front: there’s nothing new in [David Cambridge]’s brushless motor and controller build. If you’re looking for earth-shattering innovation, you’d best look elsewhere. But if you enjoy an aimless use of just about every technique and material in the hacker’s toolkit employed with extreme craftsmanship, then this might be for you. And Nixies — he’s got Nixies in there too.

[David]’s build started out as a personal exploration of brushless motors and how they work. Some 3D-printed parts, a single coil of wire, and a magnetic reed switch resulted in a simple pulse motor that performed surprisingly well. This morphed into a six-coil motor with Hall-effect sensors and a homebrew controller. This is where [David] pulled out all the stops on tools — a lathe, a plasma cutter, a welder, a milling machine, and a nice selection of woodworking tools went into making parts for the final motor as well as an enclosure for the project. And because he hadn’t checked off quite all the boxes yet, [David] decided to use the 3D-printed frame as a pattern for casting one from aluminum.

The finished motor, with a redesigned rotor to deal better with eddy currents, joined the wood and metal enclosure along with a Nixie tube tachometer and etched brass control plates. It’s a great look for a project that’s clearly a labor of self-edification and skill-building, and we love it. We’ve seen other BLDC demonstrators before, but few that look as good as this one does.

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