One glimpse at the still images or the brief video below shows you exactly how [Eric Nguyen] managed to pull this off. Each segment of the display is made up of four 0.25″ (6.35 mm) steel balls, picked up and held in place by magnets behind the plain wood face of the clock. But the electromechanical complexity needed to accomplish that is the impressive part of the build. Each segment requires two servos, for a whopping 28 units plus one for the colon. Add to that the two heavy-duty servos needed to tilt the head and the four needed to lift the tray holding the steel balls, and the level of complexity is way up there. And yet, [Eric] still managed to make the interior, which is packed with a laser-cut acrylic skeleton, neat and presentable, as well he might since watching the insides work is pretty satisfying.
We love the level of craftsmanship and creativity on this build, congratulations to [Eric] on making his first Arduino build so hard to top. We’ve seen other mechanical digital displays before, but this one is really a work of art.
As wonderful as mechanical keyboards are, most of the pre-fab and group buy models out there have zero media controls. If you want rotary encoders and OLED screens to show what function layer you’re working in, you’ll probably have to build your own keyboard from the ground up.
Hackaday alum [Cameron Coward] got around this problem by building an electromechanical buddy for his keyboard that works as a volume control. Now that we don’t rely on them to make phone calls, rotary dials are a fun throwback to a time that seems simpler based on its robust and rudimentary technology. This one is from a lovely burnt orange Bell Trimline phone, which was peak rotary dial and one of the idea’s last gasps before tone dialing took over completely.
Operationally speaking, [Cameron] is reading in the dial’s pulses with an Arduino Nano and using a Python script to monitor the serial connection and translate the pulses to volume control. We like that this is isn’t a volume knob in the traditional sense — it’s a game of percentages. Dialing ‘2’ gives 20% volume across all programs, and ‘8’ raises it to 80% of maximum. Need to mute? Just dial ‘0’, and you’ll begin to understand why people wanted to move on from rotary dialing. It won’t take that long, but it’s not instant. Check out the demo after the break.
This isn’t the first time we’ve seen a rotary dial used to control volume, but that’s one of the minor selling points of this rotary cell phone.
Spring is headed back toward the northern hemisphere, and we’ll soon see brilliant tulips waking up from their dirt naps to dot the thawing landscape with vibrant hues. These harbingers of spring are closely associated with the Netherlands, but they are actually native to Turkey and central Asia, and weren’t brought to Europe until the 1500s. Tulips became so immensely popular that the market reached what is considered the first speculative financial fever pitch, and crashed hard in 1637.
This electromechanical parlor game arranges the tulips with another artifact of the Dutch Golden Age — hand-painted Delft tiles designed to line fireplaces. [BuiltByBlatt] made all 114 of his on a CNC with a paint pen. To play the game, you roll a small ball toward a row of holes with different point values. Each hole has a break beam detector so the Raspberry Pi knows what you scored.
There’s also a rotating bonus hole that changes based on how many balls are left. As your score goes up, Titus the Tulip works his way to the right. It seems like it’d be fairly easy to hit the 5-point hole in the middle, but the tiles give it a horizontal Pachinko feel that makes it move less predictably. Slip into your clogs and check it out after the break.
Out in the neon-painted desert of Las Vegas, if you know where to look, you can find an old, 1980s electromechanical horse racing game called Sigma Derby. In this group game, you and several drunk strangers sit around a machine the size of a pool table and bet on tiny horses at 25 cents a throw. There is no skill involved, it’s all chance. This is not that game.
[Alex Kov]’s electromechanical horse racing game is a unicorn compared to Sigma Derby, or at least a zebra. This game takes patience, skill, and cunning. And unlike Sigma Derby, you can easily replicate it at home with a few shakes of the old junk bin. You just need a couple of motors, transistors, electrolytic caps, and some passives.
The idea is simple — advance horse, be first, win prizes — but it’s not that easy. While the switch is unpressed, the circuit charges up a capacitor. Press it and the horse noses forward, draining the cap. There is never enough chooch in the cap to reach the finish line, so the real game is in building up more juice than the other guy, and then staying ahead or overtaking him with the next spurt. Place your bets and catch the action after the break.
A scoreboard would be a great addition to this game. If you want to keep it electromechanical, we have some tote board inspiration for you.
Like many other classics it’s easy to come up with ways to ruin Tetris, but hard to think of anything that will make it better. Adding more clickiness is definitely one way to improve the game, and playing Tetris on a flip-dot display certainly manages to achieve that.
The surplus flip-dot display [sinowin] used for this version of Tetris is a bit of an odd bird that needed some reverse engineering to be put to work. The display is a 7 x 30 matrix with small dots, plus a tiny green LED for each dot. Those LEDs turned out to be quite useful for replicating the flashing effect used in the original game when a row of blocks was completed, and the sound of the dots being flipped provides audio feedback. The game runs on a Teensy through a custom driver board and uses a Playstation joystick for control. The video below, in perfectly acceptable vertical format, shows the game in action and really makes us want to build our own, perhaps with a larger and even clickier flip-dot display.
Electromagnetic actuators exert small amounts of force, but are simple and definitely have their niche. [SeanHodgins] took a design that’s common in flip-dot displays as well as the lightweight RC aircraft world and decided to make his own version. He does a good job of explaining and demonstrating the basic principles behind how one of these actuators works, although the “robotic” application claimed is less clear.
It’s a small, 3D printed lever with an embedded magnet that flips one way or another depending on the direction of current flowing through a nearby coil. Actuators of this design are capable of fast response and have no moving parts beyond the lever itself, meaning that they can be made very small. He has details on an imgur gallery as well as a video, embedded below.
Here at Hackaday, we love to see old hardware treated with respect. A lovingly restored radio or TV that’s part of our electronic heritage is a joy to behold, and while we understand the desire to stream media from a funky retro case, it really grates when someone throws away the original guts to make room for new electronics.
Luckily, this Seeburg jukebox wall remote repurposing is not one of those projects. [Scott M. Baker] seems to have an appreciation for the finer things, and when he scored this classic piece of Mid-Century Americana, he knew just what to do. These remotes were situated around diners and other hangouts in the 50s and 60s and allowed patrons to cue up some music without ever leaving their seats. They were real money makers back in the day, and companies put a lot of effort into making them robust and reliable.
[Scott]’s first video below shows the teardown of this unit; you can practically smell the old transformer and motor windings. His goal in the second video was to use the remote to control his Raspberry Pi jukebox; he wisely decided to leave everything intact and use the original electromechanically generated pulses to make selections. His analysis led to a nicely executed shield for his Pi which conditions the pulses and imitates coin drops; happily, the coin mechanism still works too, so you can still drop a quarter for a tune.