[Sigurd] manage to obtain an old vending machine from his dorm. The only problem was that the micocontroller on the main board was broken. He and his friend decided they could most likely get the machine back into working order, but they also knew they could probably give it a few upgrades.
This system uses two Arduino Pro Minis and an Electric Imp to cram in all of the new features. One Arduino is connected to the machine’s original main board. The Arduino interfaces with some of the shift registers, relays, and voltage regulators. This microcontroller also lights up the buttons on the machine as long as that particular beverage is not empty. It controls the seven segment LED display, as well as reading the coin validator.
The team had to reverse engineer the original coin validator in order to figure out how the machine detected and counted the coins. Once they figured out how to read the state of the coins, they also built a custom driver board to drive the solenoids.
A second Arduino is used to read NFC and RFID cards using a Mifare RC522 reader. The system uses its own credit system, so a user can be issued a card with a certain amount of pre-paid credit. It will then deduct credit appropriately once a beverage is vended. The two Arduinos communicate via Serial.
The team also wanted this machine to have the ability to communicate with the outside world. In this case, that meant sending cheeky tweets. They originally used a Raspberry Pi for this, but found that the SD card kept getting corrupted. They eventually switched to an Electric Imp, which worked well. The Arduino sends a status update to the Imp every minute. If the status changes, for example if a beverage was dispensed, then the Imp will send a tweet to let the world know. It will also send a tweet to the maintenance person if there is a jam or if a particular slot becomes empty. Continue reading “A Tweeting Vending Machine”
Steampunk extraordinaire [Jake von Slatt] has released his latest creation. This time he’s built a Wimshurst machine from mostly 3D printed parts. The Wimshurst machine is an electrostatic generator and was originally invented in the late 1800’s by James Wimshurst. It uses two counter-rotating disks to generate an electrostatic charge which is then stored in two Leyden jars. These jars are also connected to a spark gap. When the voltage raises high enough, the jars can discharge all at once by flashing a spark across the gap.
[Jake’s] machine has a sort of Gothic theme to it. He designed the parts using Autodesk’s 123D Design. They were initially printed in PLA. Skate bearings were used in the center of the disks to ensure a smooth rotation. The axle was made from the fiberglass shaft of a driveway reflector. The vertical supports were attached the base with machine screws.
The Leyden jars were made from sections of clear plastic tube. The caps for the jars were 3D printed and are designed to accept a short length of threaded 1/8″ pipe. Copper wire was used for the interior contacts and are held in place with electrical tape. The metal sectors on each disk were made from pieces of cut aluminum tape.
You may be wondering how this machine works if it’s almost entirely made out of plastic. [Jake] actually painted most of the parts with a carbon paint. This makes them electrically conductive and he can then use the parts to complete electrical circuits. Unfortunately he found this to be rather ineffective. The machine does work, but it only produces sparks up to 1/2″ in length. For comparison, his other machine is capable of 6″ sparks using similar sized Leyden jars.
[Jake] actually tried rebuilding this project using ABS, thinking that the PLA may have been collecting moisture from his breath, but the result is still only 1/2″ sparks. He suspects that the bumpy surface of the plastic parts may be causing the charge to slowly leak away, preventing a nice build up. He’s released all of his designs on Thingiverse in case any other hackers want to give it a whirl.
[Ben Krasnow] is on a mission. He’s looking for the perfect chocolate chip cookie. To aid him in this noble endeavor, he’s created the cookie perfection machine. From cleaning with plasma, to a DIY CT scanner, to ruby lasers, to LED contact lenses, [Ben] has to be one of the most prolific and versatile hackers out there today. What better way to relax after a hard day of hacking than to enjoy a glass of milk and a perfect chocolate chip cookie?
This is actually an update to the machine we first saw back in 2012. [Ben] has loaded his machine up with ingredients, and has everything under computer control. The machine will now dispense the exact amount of ingredients specified by the computer, measured by a scale. Everything happens one cookie at a time. The only downside is that the machine doesn’t have a mixer yet. [Ben] has to mix a single cookie’s worth of dough for every data point. His experiments have returned some surprising results. Too little flour actually results in a crisper cookie, as the wetter dough spreads out to a thinner layer. [Ben] also found that adding extra brown sugar also doesn’t result in a more chewy cookie. Even though he’s still in the early experimentation phases, [Ben] mentions that since it’s hard to make a bad chocolate cookie, even his failures taste pretty good.
Continue reading “[Ben Krasnow] Did It All For The (Perfect) Cookie”
The boys over at North Street Labs built a handheld burning laser and made it look super simple. Well it’s not. We don’t think it’s hard either, but the only reason it looks so easy is because they really know what they’re doing.
The first step was to source the best parts for the application. They’re using a handheld flashlight body which is small but still leaves plenty of room for the components. Next they ordered a quality lens made for the wavelength of the diode, as well as a prefab driver board.
Now the real build starts. They hit the metal lathe and machined a housing for the diode out of some aluminum stock. To marry the parts together they applied some thermal paste, and used a wrench socket to protect the diode from the pressure the vice jaws exert. It slid into place and the whole thing fits perfectly in the flashlight housing. The project wouldn’t be complete without video proof of it burning stuff. You’ll find that after the break.
Continue reading “Laser so easy to build anyone can burn their eyes out”
If you like marble machines, or if you simply like alliteration, prepare to be amazed. [Denha] apparently has had a lot of time to spare over the years, as the marble machine collection he’s amassed is quite incredible. Dating back to 2009, the collection includes relatively simple machines, like the one pictured at the beginning, to one that includes physical logic gates around 5:30.
Interestingly enough, even the “simple” one that consists of two mechanisms to lift the marbles and a slide has a trick up it’s sleeve. The slide is actually modular, so that you can use the same “pumping” mechanism with different slide designs. Not that this is the only “pump” design, the last machine featured a marble lifting mechanism with an ingenious linkage assembly that translates the motion of a motor into a sort of lifting hand.
If this wasn’t enough Maddness, there is another marble-lifting surprise awaiting you in the video after the break around 4:35! Continue reading “Multiple Marble Machine Mayhem”
While some projects we feature are meant to perform a useful function or make life easier, others such as this art installation by [Pe Lang] are far less functional, but amazing nonetheless.
Taking a cue from CNC-style machines, his creation is an experiment in falling objects and the properties of water. The machine methodically moves along a small 370 x 330 mm plate that is constructed out of a special omniphobic material. A syringe full of water travels along with the machine’s arm, depositing a single 3.3 mm wide drop of water on the board every few seconds as it moves along. Due to the surface tension of the water, each droplet forms a near perfect sphere on the plate without disturbing any of its neighbors.
Once the machine is finished, it leaves the matrix of water droplets to evaporate, after which the machine starts its careful process once again. It really is amazing, regardless of the fact that it doesn’t exactly “do anything”.
Be sure to check out the video below to see the exhibit in action.
Continue reading “Machine precisely, methodically arranges water droplets”
We can’t think of a single person who doesn’t enjoy playing with a handful of rare earth magnets now and again. We know that [Dave Johnson] certainly does. As a gift to his father in law, he constructed a magnificent machine that does little more than manipulate spherical rare earth magnets with hypnotizing grace.
The machine is constructed almost entirely from wood, save for a few fasteners and rods. Even the gears have been carefully cut from wood, with special attention paid to ensure smooth operation. When cranked, the machine slices off a single magnet from one end of a long chain, passing it along to a lift arm. The lift arm deposits the magnet into a metal tube, and with the help of eddy currents, it drifts slowly down before being redeposited at the end of the magnet chain.
Be sure to check out a video demonstration of the machine after the break, it really is fun to watch.
Continue reading “Hand-cranked magnet machine is endless fun”