Misc Hacks

4086 Articles

DIY LEGO Record Cleaner Is Revolutionary

January 16, 2021 by 31 Comments

There are many schools of thought when it comes to keeping vinyl records clean. It’s a ritual that’s nearly as important as the one that comes after it — queuing up the record and lowering the needle. We’ve seen people use everything from Windex and microfiber towels to ultrasonic cleaning machines that cost hundreds or even thousands. In the midst of building a beefier ultrasonic record cleaner and waiting for parts, [Baserolokus] looked around at all the LEGO around the house and decided to build a plastic prototype in the interim.

The idea behind ultrasonic cleaning is simple — high-frequency sound waves pumped through distilled water produce tons of tiny bubbles. These bubbles gently knock all the dirt and grime out of the grooves without using any brushes, rags, or harsh cleaners. [Baserolokus] built two pieces that hang on the edge of a washtub. On one side, a Technic motor spins the record at just under one RPM, it spins against a 3D printer wheel embedded in the other side. Check it out in action after the break.

Cleaning your vinyl is a great first step, but you might be ruining your records with a sub-par turntable. Take a deep dive with [Jenny List]’s thorough primer on the subject.

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Interference Patterns Harnessed For Optical Logic Gates

January 16, 2021 by 16 Comments

The basics of digital logic are pretty easy to master, and figuring out how the ones and zeroes flow through various kinds of gates is often an interesting exercise. Taking things down a level and breaking the component AND, OR, and NOR gates down to their underlying analog circuits adds some complexity, but the flow of electrons is still pretty understandable. Substitute all that for photons, though, and you’ll enter a strange world indeed.

At least that’s our take on [Jeroen Vleggaar]’s latest project, which is making logic gates from purely optical components. As he himself admits in the video below, this isn’t exactly unexplored territory, but his method, which uses constructive and destructive interference, seems not to have been used before. The basic “circuit” consists of a generator, a pair of diffraction patterns etched into a quartz plate, and an evaluator, which is basically a pinhole in another plate positioned to coincide with the common focal point of the generator patterns. An OR gate is formed when the two generators are hit with in-phase monochromatic light. Making the two inputs out of phase by 180° results in an XOR gate, as destructive interference between the two inputs prevents any light from making it out of the evaluator.

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Lego Tank Fires Soccer Ball Cannon

January 15, 2021 by 5 Comments

Back in the 20th century, Lego Technic was a popular toy designed to teach kids about mechanical technology, and be a lot of fun to boot. Motors and pneumatics were available, but by and large you had to move your creations and make the noises yourself. That’s not the case these days, as the [Brick Experiment Channel] demonstrates with this impressive Lego tank.

The drivetrain is straightforward, using standard Lego tank treads with each side given its own motor for easy skid steering. However, the real party piece is the slingshot cannon, which launches Lego soccer balls at 60 km/h. Utilizing several motors, it’s complete with elevation adjustment for accurate ranging, and a 6 round magazine so you can (slowly) prosecute your targets with rounds downrange.

What really makes this build great is the control system, with the tank being controlled by a PS4 controller via Sbrick, a device that lets Lego motors be controlled via Bluetooth. We’d love to build a couple of Lego vehicles and have them blast away at each other. We’ve seen the technology used before for a secret heist robot. Video after the break.

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Hex Matrix Clock Does It With Six Sides

January 13, 2021 by 18 Comments

LED matrixes were once a total headache, requiring careful consideration to make the most of limited I/O pins and available microcontroller resources. These days, addressable LED strings have made it all a cinch. Thus, going a little out of the box isn’t so daunting. [w.r.simpson] did just that with this hex-matrix clock.

Relying on hexes instead of a normal Cartesian grid requires some attention to how the rows and columns are laid out, but the Instructable goes through the necessary coordinate system to address the display. The whole display was built without a 3D printer, instead relying on some basic craft skills and a picture frame as the enclosure. Strips of WS2812B LEDs were used to build the hexagonal matrix, run by a Adafruit Metro Mini 328. To give each hexagonal pixel, or hexel, a crisp outline, a shadow grid was built using black paper to stop the light bleeding between the display segments when switched on. Smoked plexiglas wasn’t available, so instead, tinted window film was used to darken the front of the display.

The result is impressive; while some glue marks from the shadow grid are visible closeup, from a distance the final product looks incredibly futuristic thanks to the hexagonal layout. We can imagine this would make a great set dressing in a futuristic film clip; we fully expect to see this concept in the background of the next Ariana Grande single. If this build isn’t enough six-sided fun to sate your appetite, consider getting into Super Hexagon too!

Making A Kid-Friendly Computer As A Present: Or How To Be The Cool Aunt At Christmas

January 13, 2021 by 24 Comments

This article was meant to be finished up before Christmas, so it’ll be a little late whenever you’re reading it to go and prepare this for the holiday. Regardless, if, like me, should you ever be on the lookout for something to give a toddler nephew or relative, it could be worth it to look into your neglected old parts shelves. In my case, what caught my eye was a 9-year-old AMD laptop catching dust that could be better repurposed in the tiny hands of a kid eager to play video games.

The main issues here are finding a decent selection of appropriate games and streamling the whole experience so that it’s easy to use for a not-yet-hacker, all the while keeping the system secure and child-friendly. And doing it all on a budget.

This is a tall order, and requirements will be as individual as children are, of course, but I hope that my experience and considerations will help guide you if you’re in a similar boat.

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HackadayU Announces Rhino, Mech Eng, And AVR Classes During Winter Session

January 12, 2021 by 13 Comments

The winter lineup of HackadayU courses has just been announced, get your tickets now!

Spend those indoor hours leveling up your skills — on offer are classes to learn how to prototype like a mechanical engineer, how to create precision 3D models in Rhino, or how to dive through abstraction for total control of AVR microcontrollers. Each course is led by an expert instructor over five classes held live via weekly video chats, plus a set of office hours for further interaction.

  • Introduction to 3D using Rhino
    • Instructor: James McBennett
    • Course overview: Introduces students to Rhino3D, a NURBS based 3D software that contains a little of everything, making it James’ favorite software to introduce students to 3D. Classes are on Tuesdays at 6pm EST beginning January 26th
  • Prototyping in Mechanical Engineering
    • Instructor: Will Fischer
    • Course overview: The tips and tricks from years of prototyping and mechanical system design will help you learn to think about the world as a mechanical engineer does. Classes are on Tuesdays at 1pm EST beginning January 26th
  • AVR: Architecture, Assembly, & Reverse Engineering
    • Instructor: Uri Shaked
    • Course overview: Explore the internals of AVR architecture; reverse engineer the code generated by the compiler, learn the AVR assembly language, and look at the different peripherals and the registers that control their behavior. Classes are on Wednesdays at 2pm EST beginning January 27th

Consider becoming an Engineering Liaison for HackadayU. These volunteers help keep the class humming along for the best experience for students and instructors alike. Liaison applications are now open.

HackadayU courses are “pay-as-you-wish” with a $10 suggested donation; all proceeds go to charity with 2019 contributions topping $10,100 going to STEAM:CODERS. There is a $1 minimum to help ensure the live seats don’t go to waste. Intro videos for each course from the instructors themselves are found below, and don’t forget to check out the excellent HackadayU courses from 2020.

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Dangerous Greeting Cards You Probably Shouldn’t Send Anyone

January 11, 2021 by 25 Comments

Regular paper greeting cards are pricey for what they are, and of course the annoying musical variety are even more so. If you really want to go all out, however, you’ve got to go custom made. That’s what [Xyla] and [Ian] did, though we’d stop short of recommending you build or send these to anyone!

Two variants of the “dangerous cards” were built. One repurposed an electric shocking circuit from a handheld buzzer, tucking it inside a shiny Disney greeting card. Using a switch from a musical greeting card, when opened, the shocking circuit is activated. With the circuit connected to aluminium tape electrodes hidden in the shiny foil design, when the user opens the card, they receive a painful shock. The flamethrowing variant was triggered by the same mechanism, though instead sent power to an electric match, shooting a fireball with flash cotton when the card was opened.

These cards make excellent pranks, though we’d be wary about sending them by mail for obvious reasons. We’ve seen [Xyla’s] work before too, with her glowing kayak a particular highlight. Video after the break.

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