Misc Hacks

4165 Articles

The Ultimate Puzzle Desk — MYST Eat Your Heart Out

December 25, 2015 by 11 Comments

This project is absolutely mind boggling. Created by [Kagen Sound], this desk would fit right at home inside the MYST games. It has a pipe organ inside, and you can open a secret compartment by playing a specific tune.

Besides being an absolute marvel of woodworking, the hidden mechanics inside this desk make our heads hurt. The pipe organ aspect works by pushing in little drawers — this forces air into organ pipes at the front of the desk. But some of the air is redirected into a pneumatic memory board — which can actually keep track of the notes you play. When the correct tune is played, it triggers a pendulum which releases a secret compartment. All you need is a trap door over an abyss and you’ve recreated The Goonies.

Sure, it’d be easy to do that with an Arduino or something… but the pneumatic memory board is made of wood. Entirely made of solid wood. [Kagen] says it took countless hours to design, at least five different versions before he found one that worked.

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POV Globe Display Spins Up Full Color Tupac

December 24, 2015 by 11 Comments

Persistence of vision projects were once all the rage, judging by a quick review of the literature here on Hackaday. They’ve tapered off a bit lately, but this impressive full-color globe display might just kick-start some new POV projects.

Built as a final project for an EE course, [Evan] and [Kyle]’s project is more about the control electronics and programming than the mechanical end of the build. Still, spinning a 12″ ring of 1/4″ thick acrylic with a strip of APA102 LEDs glued to the edge takes some thoughtful engineering. While the build appears sturdy, [Evan] does admit to a bit of wobble under full steam, which was addressed by adding some weight to the rig. We wonder if mounting half the LEDs on each side of the ring to balance the forces wouldn’t have worked better. True, it would have complicated the coding for the display, but maybe that would have been good for extra points. In any case, the display turned out well and the quality of the images is great. And as an aside: how awesome is it that we live at a time when you can order a six-circuit slip-ring for a project like this for less than $20?

It’s the end of the semester and we love seeing the final projects that have just made it across the finish line. This globe is one, yesterday we saw a voice-controlled digital eye exam, and if you have or know of a final project, don’t forget send us the link!

If POV globes are your thing, be sure to set the Hackaday WABAC machine a few years and check out this Death Star design from 2012 or this globe from 2010.

Electrolytic Capacitor Repair

December 24, 2015 by 18 Comments

If you’ve ever worked on old gear, you probably know that electrolytic capacitors are prone to failure. [Dexter] undertook a repair of some four-decade-old capacitors in a power supply. He didn’t replace them. He fixed the actual capacitors.

The reason these units are prone to fail is the flip side of what people like about electrolytics: high capacitance in a small package. In a classic parallel plate capacitor, the capacity goes up as the distance between the plates shrinks. In an electrolytic, one plate is a rolled up spiral. The other plate is conductive fluid. The insulator between (the dielectric) is a very thin layer of oxide that forms on the spiral. Over time, the oxide degrades, but this degradation repairs itself when using the capacitor. If the capacitor isn’t powered up for an extended period, the oxide will degrade beyond the point of self-repair.

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Before Google There Was The Chemical Rubber Company

December 23, 2015 by 40 Comments

Quick. What’s the difference in conductivity between silver and copper? Today, that’s easy to find out. You just ask Google (maybe even out loud if you have a phone handy). But it wasn’t that long ago that you needed another option. Before the Internet age, a big part of being “that guy” (or gal) was knowing where to go to find things. You had to be a master of the library’s reference section, know what might be in an encyclopedia or an almanac.

However if you were a hardcore math, science, or engineering geek you probably had, at least, one edition of CRC handbooks. Today, we usually think of CRC as cyclic redundancy check, but back then it was the Chemical Rubber Company.

The Chemical Rubber Company dates back to 1903 when brothers Arthur, Leo, and Emanuel Friedman were selling rubber lab aprons in Cleveland, Ohio (Arthur, apparently, had been in a similar business from 1900). In 1913, the brothers offered a short (116-page) booklet called the Rubber Handbook free with the purchase of a dozen aprons.

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God On The CB Radio

December 23, 2015 by 37 Comments

Sometimes art pushes boundaries. We’ve covered a lot of tech art that blurs the lines between the craft of engineering and high-concept art theory. Praydio, by [Niklas Roy] and [Kati Hyyppä] leans easy on the tech, but pushes against viewers’ religious sensibilities.

Playing with the idea of talking directly to God, and with the use of altars as a focal point to do so, [Niklas] and [Kati] took the extremely literal route: embedding a CB radio into a dollar-store shrine. The result? If you’re lucky, someone will answer your prayers, although we’re not too hopeful that the intervention will be divine.

The art critic in us would say that this is a radical democratization of religious authority in that anyone who is tuned in can play the role of Jesus. Or maybe we’d say something about the perception of religious significance in the seemingly random events of our everyday life — maybe it’s not just chance that someone is tuning in at the time you’re asking for help?

Honestly, though, we think they’re just having a bit of fun. The video (below the break) shows someone asking Jesus for a coffee, and the artist on the other end laughs and fetches him one. It’s not high-tech, and it’s not even amateur radio the way we usually think of it, but something about the piece made us laugh, and then to think for a bit. Even if this art isn’t your style, check out [Niklas’] website — he’s got tons of fun projects written up, a few of which we’ve covered here before.

The Scientific Implausibility Of Starkiller Base

December 22, 2015 by 112 Comments

This post contains spoilers for Star Wars: The Force Awakens. These spoilers won’t affect you if you haven’t seen the movie; they’re equivalent to saying, “in A New Hope there’s a moon sized battle station with a superlaser” and “someone gets a hand amputated with a lightsaber in a Star Wars movie”

A lot has happened in the Star Wars universe since the battle of Endor. The Empire is in ruins, and Yavin 5 and the forest moon of Endor both have new planetary ring systems. The Rebellion has given way to a new Galactic Republic, but there is a spectre of evil looming in the unknown areas of the galaxy: the First Order, a malevolent force that has built a planet-sized superweapon capable of destroying entire planetary systems from across the galaxy. The Starkiller gets its energy from harvesting entire suns, moving from one solar system to another to feed this massive weapon of terror.

We’ve had nearly forty years to argue the plausibility of the Death Star, lightsabers, parsecs as a unit of time, and hyperdrives. It’s time to pass the hallowed tradition of arguing over fictional spacecraft to a new generation. Starkiller Base is a cool idea, but does the science behind it hold up? No. It’s completely implausible. It makes for a great story, but it’s completely implausible.

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Muscle Wire Pen Dances To Duke Nukem

December 22, 2015 by 2 Comments

[serdef] is clearly just having a little bit of fun here. One never needs a whiteboard pen that’s syncronized by MIDI to dance along with the theme from Duke Nukem.

But if you had all of the parts on hand (a highly liquid MIDI-driven relay board that connects straight up to a soundcard, some muscle wire, tape, and a whiteboard pen, naturally) we’re pretty sure that you would. You can watch the dancing pen in a video below the break.

The project is really about documenting the properties of [serdef]’s muscle wire, and he found that it doesn’t really contract enough with a short piece to get the desired effect. So he added more wire. We’ve always meant to get around to playing with muscle wire, and we were surprised by how quickly it reacted to changing the voltage in [serdef]’s second video.

Now the dancing pen isn’t the most sophisticated muscle wire project we’ve ever seen. And that award also doesn’t go to this Nitinol-powered inchworm. Did you know that there’s muscle wire inside Microsoft’s Surface?

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