Just about all of us have a few old hard drives in our junk box. There are a myriad of projects out there to put them to work in new and interesting ways. One of those ways is to turn your hard drive into a solenoid motor of sorts. (YouTube link) This isn’t a new hack, videos of it have been kicking around the internet for years. [black1985vette] gives a pretty good explanation of how he’s done it. He used a piece of brass as a connecting rod between the drive head and a pin mounted off-center to the platter hub. One of the platter mounting screws provides the perfect place to set the pin. A bent safety-pin rubs the center of the hub, which is partially insulated with tape. When the pin contacts the hub, the drive head is energized, pushing the whole assembly around. The mass of the platters acts as a flywheel, carrying the motor the rest of the way around.
[Pulverrostmannen] performed a similar mod, though he used a micro switch to time the drive head. Rather than a brass connecting rod, [Pulverrostmannen] used a spare head. With a simple transistor circuit acting as a speed control, his hard drive motor revved up to around 1560 RPM, which is pretty respectable for a bunch of junk parts.
So next time you’re stuck in on cold rainy weekend, pull out some of those old drives and get hacking! Click past the break to several of these projects in action.
Continue reading “Spin up an old hard drive with a solenoid motor”
Planting your car just about anywhere almost always comes at a price; and, if you’re overdue for your return, odds are good that you’ll end up paying a much steeper price than intended. Parking meters are wonderful devices at telling the authorities just how much time you have left until you’re ticketworthy. [Zack] figured that five–even ten minutes late—is an absurd reason to pay a fine, so he’s developed a tool that will preload a meter with a few extra coins when the authorities get too close.
The law-enforcement detection system puts together of number of tools and techniques that we’re intimately familiar with: 3D printing, Arduino, a photoresistor, and a proximity (PIR) sensor. At the code level, [Zack] filters his analog photo resistor with a rolling average to get a clean signal that triggers both by day and by night. The trigger? Two possibilities. The PIR sensor detects curious law enforcement officers while the filtered photoresistor detects the periodic twirling siren lights. Both events will energize a solenoid to drop a few extra coins through a slide and into the meter slot.
For a collection of well-known components, [Zack] could’ve packed his contraption into a Altoids Tin and called it a day. Not so. As an interaction designer, looks could make or break the experience. For this reason, he opts for a face-hugging design with a steampunk twist. Furthermore, to achieve compatibility across a range of devices, [Zack’s] CAD model is the result of adjusting for various meter profiles from images he snapped in the urban wilderness. The result? A clean, authentic piece of equipment compatible with a family of meters.
For the shrewd-eyed observers, [Zack’s] first video post arrived online in 2011, but his work later resurfaced at a presentation in the 2015 Tangible, Embedded, and Embodied Conference by his former design instructor [Eric Paulos], who was eager to show off [Zack’s] work. For a deeper dive into the upcoming second edition, head on over to [Zack’s] image feed.
Continue reading “Auto-Meter Reader Feeder Keeps Meter-Maids at Bay”
[Ramon] was always fascinated with pianos, and when he came across a few player piano rolls in an antique shop, a small kernel of a project idea was formed. He wondered if anyone had ever tried to convert a player piano into a full MIDI instrument, with a computer tickling the ivories with a few commands. This led to one of the best builds we’ve ever seen: a player piano connected to a computer.
[Ramon] found an old piano in Craigslist for a few hundred dollars, and once it made its way into the workshop the teardown began. Player pianos work via a vacuum, where air is sucked through a few pin points in a piano roll with a bellows. A series of pipes leading to each key translate these small holes into notes. Replicating this system for a MIDI device would be impossible, but there are a few companies that make electronic adapters for player pianos. All [Ramon] would have to do is replicate that.
The lead pipes were torn out and replaced with 88 separate solenoid valves. These valves are controlled via a shift register, and the shift registers controlled by an ATMega. There’s an astonishing amount of electronic and mechanical work invested in this build, and the finished product shows that.
As if turning an ancient player piano into something that can understand and play MIDI music wasn’t enough, [Ramon] decided to add a few visuals to the mix. He found a display with a ratio of 16:4.5 – yes, half as tall as 16:9 – and turned the front of the piano into a giant display. The ten different styles of visualization were whipped up in Processing.
The piano has so far been shown at an interactive art exhibit in Oakland, and hopefully it’ll make it to one of the Maker Faires next year. There are also plans to have this piano output MIDI with a key scanner underneath all the keys. Very impressive work.
Continue reading “Making a Player Piano Talk MIDI”
Hang around Hackaday long enough and you’ll hear about MAME, and all the other ways to emulate vintage arcade machines on a computer. The builds are usually fantastic, with real arcade buttons, MDF cabinets, and side graphics with just the right retro flair to make any connoisseur of ancient video games happy. MAME is only emulating old video games, though, and not physical systems like the digital pinball system [ronnied] put up on the Projects site.
[ronnied] was inspired by a real life, full-size White Water pinball machine at his previous job, and decided it was high time for him to acquire – somehow – a pinball machine of his own. He had a spare computer sitting around, an old 16:9 monitor for the main playfield, and was donated a smaller 4:3 monitor for the backglass. With an MDF cabinet, PinMAME, and a little bit of work, [ronnied] had his own machine capable of recreating hundreds of classic machines.
The build didn’t stop at just a few arcade buttons and a screen; [ronnied] added a 3-axis accelerometer for a tilt mechanism, solenoids and a plunger torn from a real pinball machine for a more realistic interface, and a Williams knocker for a very loud bit of haptic feedback. We’ve seen solenoids, buzzers, and knockers in pinball emulators before, and the vibrations and buzzing that comes with these electromechanical add ons make all the difference; without them, it’s pretty much the same as playing a pinball emulator on a computer. With them, it’s pretty easy to convince yourself you’re playing a real machine.
Videos of the mechanisms below.
Continue reading “Digital Pinball With Force Feedback”
Hosting a New Year’s Eve party, but don’t want to be stuck behind the bar all night? You could set out a bowl or two of
spiked punch, but where’s the hack? Free yourself from drink slinging duties with the Automated Drink Mixer created by Cornell University students [Justin] and [Austin]. Their design uses a 14″ diameter lazy Susan powered by a 12V bi-directional motor attached to a 2″ rubber wheel. The motor is capable of 70RPM, so the glass ultimately rides around at 10RPM. Orders are entered on a push-button menu. As this is a school project that should adhere to IEEE standards, all libations are non-alcoholic.
The software uses an overarching state machine, so the system polls for input from the menu at idle. When it receives an order, the lazy Susan rotates the glass to the right spout or series of spouts and then returns it to the starting point. [Justin] and [Austin] controlled the position of the glass with an IR emitter and phototransistor. This pair detects the black strips of tape around the edge which are spaced 60° apart. A comparator digitizes the signal and triggers an interrupt in the software, which counts the number of 60° slices. A full demonstration is waiting for you after the jump. Before you jump: drink responsibly, kids. If you aren’t up to that particular challenge, make yourself an alcohol-aware LED ice cube. If you need more LEDs in your life, whip up the Inebriator.
Continue reading “Automated Drink Mixer Is the Life of the Party”
While casually lurking on a famous auction website, [TeddyDesTodes] found the gem shown in the above picture and reverse engineered it. This is a flip dot display, the Brose Vollmatrix compact to be precise. It consists of a grid of small metal discs that are black on one side and yellow on the other, set into a black background. With power applied, the disc flips to show the other side. The disc is attached to an axle which also carries a small permanent magnet. Positioned close to the magnet is a solenoid. By pulsing the solenoid coil with the appropriate electrical polarity, the magnet will align itself with the magnetic field, also turning the disc.
After carrying the 25kg display from his post office to home, [TeddyDesTodes] opened it and discovered that the main control board was using two RS422 transceivers. So he fired up his bus pirate, started to sniff the traffic and noticed that several commands were repeatedly sent. [TeddyDesTodes] stopped the transmission, sent these particular commands and had the good surprise to see some dots flipped. From there, displaying something was a piece of cake.
If this is familiar to you it may be because it was shared in one of the Trinket Contest Updates. But the background details were just so much fun we think this deserves a full feature of it’s own. Do you agree?
[Kevin] has made an interesting camera shutter mechanism using an Arduino and a solenoid. To keep it extremely simple, he is only controlling a single leaf. In the linked video, you can see him take it through its paces from 1/125 seconds up to infinite. This is, of course, a proof of concept, and [Kevin] mentions using smaller components to make everything fit easily inside a Holga-like body. As he points out in the video’s comments, digitally controlling the flash would be a simple matter as well.
A basic camera is incredibly simple to make, and [Kevin’s] design certainly isn’t complicated. That said, if you look at the big picture, [Kevin] is demonstrating how feasible it could be to build an entirely custom camera with a standard microcontroller as the brain. We can’t help but think of all of the possibilities when you are able to control the entire photo taking process.
Interestingly, [Kevin] is also behind this twin lens reflex Kickstarter project from earlier in the year. It will be interesting to see what other camera-related hacks we will see from him.