A little face protection is a great idea when first testing out your homemade bow. [Austin Karls] made this recurve bow during what he calls an engineer’s Spring break.

He settled on the idea after seeing a few other projects like it on Reddit. After first drawing up a plan he headed down to the shop to cut out the wooden riser (the middle part of a bow). Unlike traditional recurve bows this is made up of three parts. Traditionally you would laminate different types of wood to achieve the flexibility and tension levels desired. But [Austin] went with a synthetic material: the tips of two skis. Each were cut to the final length and affixed to the riser with a pair of bolts.

After a few test shots he gained confidence in the design and did away with the face mask. Now if you’re in the market to take your existing bow and add some firepower to it you’ll want to look in on this shotgun enhanced compound bow.

[Thanks Schuyler]

Filed under: weapons hacks

The RedBull Creation contest begins today.

Last year, we had a ton of fun competing in the RedBull creation contest. The idea is that RedBull hosts this big contest where teams compete by making awesome stuff. Finalists get to take a trip to Brooklyn for a build off extravaganza. Frankly, we think this is how ALL advertising budgets should be spent.

This year, however, we will not be participating as a team in the contest. We’ll be helping judge it!

The hardware:

In previous years, RedBull has sent out some custom hardware for people to use. Last year it was basically an Arduino on a custom PCB with some cool touch sensors. This year, they’ve sent out this multi purpose LED controller shield that looks pretty impressive.

You can see all the details along with a breakdown of the board from the creator himself, after the break.

From [JoeJoe], the creator of the board:

Basically, it is kind of an LED lighting multi-tool with some extra sensors and output devices on-board.  The board is controlled over I2C using an Arduino Uno R3, or you can air-wire pretty much any device that supports 400KHz (fast mode) I2C to the breakout pads.  We’ve tested it with some of custom networked devices and with Raspberry Pi, for example.  The I2C addresses of each device are written on the silkscreen of the board, though some peripherals (on PIC microcontrollers for example) expect you to use that address shifted one bit to the left (they don’t automatically add in the low read/write bit).

Onboard you will find the following:

• Two smart devices for driving 12V RGB LED strip.  Each device will drive up to four strips, for a total of 24 discrete channels.  There are built-in macros for color fades over time, pulsing, random color sweeps, etc which offload the necessity of controlling of these effects from the Arduino.  To use these, follow the wiring specified on the silkscreen for the strip, and hook up at 12V power supply to the pads/terminal block at the top of the board.  I *suppose* these could also be used to PWM any sort of device that was within the current/power specs of the MOSFET, but I’d definitely suggest snubber diodes if you were to attempt any DC motor controlling. We included 5M of RGB strip in the package.
• One “addressable LED strip multi-tool” device.  This handles the timing for controlling up to 256 RGB pixels of addressable strip based on the WS2811, WS2801, or LPD8806 IC.  We have included 1M of high-density WS2811 strip, which is the default mode for the device.  Using the library macros, you can write a framebuffer to the strip, set up gradients between two colors across a number of pixels, rotate or auto-rotate the current framebuffer at a given speed, and create a effects such as ‘comet’ chase.  To use this device, you’ll hook 5v up to the marked location in the lower left of the board.
• One DMX driving device.  This is in the lower right of the board, and is for driving 3-channel (RGB mode) DMX fixtures.  You can cut apart a 3-pin XLR cable and connect this to LED PAR cans, or any other sort of DMX fixture (fog machine maybe?).  Using the library you can write a universe of DMX which will be output continuously to the A and B pins with correct timing.
• One 512Kbit EEPROM, which may be preloaded with something interesting.  We included very rudimentary read/write functions for dealing with this on the byte level, but there are better 24LC512 libraries out there that could be used also.
• One tri-axis MEMS accelerometer.  The library has functions to read X,Y, and Z.  This Kionix unit also has a lot of functionality that we haven’t implemented such as high-pass filtering, tap and double detection, orientation change detection, and adjustable sensitivity (+2g,+4g,+6g).
• One 12-bit DAC.  This will output a waveform between 0 and 3.3V which I’m sure someone will find a good use for.
• One temperature sensor.  The library has basic functions to read the current temperature and convert the result to Celsius.
• One generally awesome looking circuit board which will nest lovingly with last year’s bullduino in eternal harmony.

For those that haven’t seen the video this campaign was inspired by:

 

 

Filed under: news

We’re surprised that we haven’t come across any of [Robert Murray-Smith's] projects before. Looking through his collection of YouTube uploads proves that he’s a very active amateur chemist (we assume this is a hobby because he performs the experiment in a mayonnaise jar). The video we’re featuring today is about ten minutes of his technique for synthesizing graphene. The video can be watched after the break. Be warned that the audio doesn’t sync with the video because he overdubbed the presentation to fix up the poor audio quality from the original.

Graphene is something of a compound-du-jour when it comes to electronic research. You may remember reading about using DVD burners to make graphene film that will go into thinks like super-capacitors to replace batteries. [Robert] starts off his process with a jar of 98% sulfuric acid and 75% phosphoric acid. He pours in powdered graphite (chemical proportions are important here) and gives it a swirl. Next some potassium permanganate is added over about five or ten minutes. From there it goes on the stir plate for three days of constant stirring. During this time the solution will go from green to brown, indicating the presence of graphene oxide.

He goes on from there, but it’s clear he hasn’t found an iron-clad route to his end goal of isolating the graphene for use in constructing things like those super-capcitors we mentioned earlier. If you’ve got a home lab and some interest perhaps you can contribute to his efforts.

[Thanks Bruno]

Filed under: chemistry hacks

We’re surprised that we haven’t come across any of [Robert Murray-Smith's] projects before. Looking through his collection of YouTube uploads proves that he’s a very active amateur chemist (we assume this is a hobby because he performs the experiment in a mayonnaise jar). The video we’re featuring today is about ten minutes of his technique for synthesizing graphene. The video can be watched after the break. Be warned that the audio doesn’t sync with the video because he overdubbed the presentation to fix up the poor audio quality from the original.

Graphene is something of a compound-du-jour when it comes to electronic research. You may remember reading about using DVD burners to make graphene film that will go into thinks like super-capacitors to replace batteries. [Robert] starts off his process with a jar of 98% sulfuric acid and 75% phosphoric acid. He pours in powdered graphite (chemical proportions are important here) and gives it a swirl. Next some potassium permanganate is added over about five or ten minutes. From there it goes on the stir plate for three days of constant stirring. During this time the solution will go from green to brown, indicating the presence of graphene oxide.

He goes on from there, but it’s clear he hasn’t found an iron-clad route to his end goal of isolating the graphene for use in constructing things like those super-capcitors we mentioned earlier. If you’ve got a home lab and some interest perhaps you can contribute to his efforts.

[Thanks Bruno]

Filed under: chemistry hacks

This is a Yamaha XG card, the SW60XG to be exact. It’s an audio card for a PC which extends the MIDI standard to include over six hundred instruments. By today’s standards the almost twenty year old card isn’t all that powerful, but it is interesting to see it used as a standalone device.

[Benji Kimba] posted the video overview of his project which you can watch after the break. The image above is found at about 2:35 seconds and about twenty seconds later you get a look at how he patched into the conductors on the edge connector on both sides followed by the MIDI in and out connections. Finally, we get a look at a proper schematic at the four minute mark which details the pull-up resistors, hardware reset circuit, and the optoisolator he added for the MIDI connections themselves.

[Thanks Gnif]

Filed under: news

This is a Yamaha XG card, the SW60XG to be exact. It’s an audio card for a PC which extends the MIDI standard to include over six hundred instruments. By today’s standards the almost twenty year old card isn’t all that powerful, but it is interesting to see it used as a standalone device.

[Benji Kimba] posted the video overview of his project which you can watch after the break. The image above is found at about 2:35 seconds and about twenty seconds later you get a look at how he patched into the conductors on the edge connector on both sides followed by the MIDI in and out connections. Finally, we get a look at a proper schematic at the four minute mark which details the pull-up resistors, hardware reset circuit, and the optoisolator he added for the MIDI connections themselves.

[Thanks Gnif]

Filed under: news

Here’s a really fascinating circuit that implements a combination lock using relays and logic gates. Even with the schematic and written explanation of how it works we’re still left somewhat in the dark. We’ll either pull out some paper and do it by hand this weekend, or build it chunk by chunk in a simulator like Atanua. Either way, the project sparked our interest enough that we want to get elbow deep into its inner workings.

From the description we know that it uses a combination of CD4017, CD4030, CD4072, and CD4081 chips. You’re probably familiar with the 4017 which is a decade counter popular in a lot of project. The other chips provide XOR, OR, and AND gates respectively. The relays were chosen for two purposes. One of them activates when a correct combination has been entered, effectively serving as the output for the combo lock. The other two are for activating the clock and affecting a reset if the wrong combination is entered.

It makes us wonder if this would be incredibly simple to brute force the combination by listening for sound of the reset relay activating? It’s hard to tell from the video after the break if you can discern a wrong digit from a right once just based on sound.

Filed under: security hacks

Here’s a really fascinating circuit that implements a combination lock using relays and logic gates. Even with the schematic and written explanation of how it works we’re still left somewhat in the dark. We’ll either pull out some paper and do it by hand this weekend, or build it chunk by chunk in a simulator like Atanua. Either way, the project sparked our interest enough that we want to get elbow deep into its inner workings.

From the description we know that it uses a combination of CD4017, CD4030, CD4072, and CD4081 chips. You’re probably familiar with the 4017 which is a decade counter popular in a lot of project. The other chips provide XOR, OR, and AND gates respectively. The relays were chosen for two purposes. One of them activates when a correct combination has been entered, effectively serving as the output for the combo lock. The other two are for activating the clock and affecting a reset if the wrong combination is entered.

It makes us wonder if this would be incredibly simple to brute force the combination by listening for sound of the reset relay activating? It’s hard to tell from the video after the break if you can discern a wrong digit from a right once just based on sound.

Filed under: security hacks

Charlieplexing is a technique that allows you to drive a larger number of LEDs than wouldn’t be possible with the same number of I/O pins on a traditional multiplexed matrix. If we lost you there just think of it as lots of blinky lights connected to a small number of pins. It works by leveraging the one-way nature of a diode. Current will only flow through an LED in one direction so if you hook up your display in a clever way you can drive multiple LEDs from one I/O by switching the polarity of that pin between voltage and ground. [M.Rule] recently looked at using Charlieplexing with LED modules. His conceptual approach to the problem is different from those we remember seeing before and it’s worth a look.

Instead of just using the formula to calculate how many LEDs he can drive [M.Rule] is using a table of I/O pins to establish how many and in what order these displays can be connected. Each colored set of blocks represents an LED module. The graphic above shows how 18-pin can be utilized. He even filled in the unused pin combinations with input buttons.

Filed under: led hacks, Microcontrollers

Let’s wind down the weekend with some projects that didn’t quite warrant their own feature, but we think they’re still worth a look.

First up is a quick tip on cracking the lids on those hard to open jars of food. [Jason] says just grab about a foot of duct tape and the lid will come flying off. And while you’re searching for that roll of tape why not grab some foil tape to build a cooking oven. [Gabriel] built this solar oven by covering curved wedges of cardboard with foil tape and combining them to form a parabolic reflector.

Next we’ve got a trio of hacks that will come in useful in your home shop or at the local Hackerspace. Organization is key, and here’s a resistor storage system that uses #6 envelopes [via Reddit]. Also useful is the tip from [Felix] about using a tile saw to get clean cuts on your circuit boards. And if you’ve ever been plagued by a laser cutter job that doesn’t fully sever the material [Dan] wrote a guide on using a fence so that you can reposition the piece for another run.

Finally, we’re hoping we weren’t the only ones that didn’t realize the Raspberry Pi has an unpopulated footprint for a reset button. Now we’ve got to figure out if it’s okay to leave the PSU plugged in (based on it’s current consumption while the RPi is in power down) and hack together some sort of TV-based reset circuit for our RPi XBMC setup.

Filed under: Hackaday links

We’ve heard quite a number of radio ads lately trying to sell an automatic lawn mowing robot (like a Roomba for your grass). But wouldn’t it be a lot more fun to hack your own from an existing lawnmower? That’s what [Daniel Epperson] did. In fact, the project has been ongoing for years. But he wrote in to share the latest development which adds solar charging capabilities to the robot mower.

First off let’s discuss the fact that this is not an electric lawnmower. This is the Prius of lawnmowers, bringing together hybrid technology to cut the grass with the gasoline powered motor, and to propel the rig with electricity. [Danny's] worked hard to shoe-horn just about every feature imaginable (other than autonomy) into the thing, and that’s why the batteries can be charged from mains, an alternator powered by the gas motor, and now from the PV panel mounted on top of it. Get the entire project overview in his roundup post.

This a wireless video feed and the mower is driven by remote-controlled. So you can give your yard a trim without getting sweaty. After the jump we’ve embedded a clip of an earlier revision demonstrating that remote control. If you’re not interest in having all the features you could simply build an analog version.

Filed under: home hacks, robots hacks

It’s easy to dismiss this one at first glance. But once you hear [Tychsen81] playing the thing you’ll want to know more.

He posted the demonstration way back in 2009. It wasn’t until a year later that he filmed the particulars of how the thing was made. The strings are actually bass guitar strings, an A and D string that are tuned down to E and A to play along with Black Sabbath’s “Ironman”. The neck is made out of two boards. One serves as the fingerboard, which is fretless. The other is mounted under that in order to provide negative space for the bridge while keeping the strings at the right height for the fingerboard. The water bottle helps to amplify the sound and that’s why the bottom end of the strings pivot on the bridge, pass through the neck, and are anchored on the bottom edge of the bottle.

We’ve embedded both the demo and the build videos after the break.

If this gets you thinking about making your own instruments you will also be interested in the Whamola.

“Ironman” Demo:

Build video:

[Thanks Herb]

Filed under: musical hacks

[Chris] has been having some real problems getting PLA to stick to the build platform of his Printrbot. This is of course not limited to this brand of printers, and affects all extruder-based hardware using the PLA as a source material. He came up with a couple of ways to fix the problem.

The first is something we’re quite familiar with. The image above shows [Chris] applying a thin layer of hairspray to the platform. This is a technique the we use with our own 3D printer. The sheets of paper are used as a mask to help keep the sticky stuff off of the threaded rod. For more info on the hairspray trick [Chris] recommends that you read this article.

The second technique uses a slurry made from saturating a bottle of acetone with ABS leftovers. In the clip after the break he shows off a glass jar of the solvent with scraps from past print jobs hanging out inside. After a couple of days like that it’s ready to use. He takes a paper towel, wets it with the solution, and wipes on a very small amount. He does mention that this will eventually eat through the Kapton tape so apply it rarely and sparingly.

Filed under: 3d Printer hacks

[Hans Peter] wanted to move away from using full Arduino boards in his projects. One of the components he rarely used after the development stage is the USB hardware. Once the firmware is flashed to the chip he didn’t need it any longer. So he tried his hand with some really small SMD parts by building this USB to serial Arduino programmer.

The chip he went with isn’t the FTDI part we’re used to. Instead of using an FT232RL, he opted for its smaller cousin the FT230x. This chip doesn’t fully implement the communications protocol of the 232, but it does work with AVRdude and that’s all that really matters. Above you can see [Hans'] creation next to the official Arduino USB-to-serial programmer. He used the same connection scheme, but went with an edge connector for the USB instead of using a mini-B jack.

It’s pretty impressive to see his prototyping work with the 16-pin QFN package. He soldered it dead-bug style to a couple of SIL pin headers in order to test it on a breadboard. The first board he assembled was too loose in the USB port, but he added some tape to the back to make it thicker, and coated the edge connector traces with a bit of solder and that did the trick.

Filed under: arduino hacks

This hack has got to be every gamer’s dream. Someone actually took the time to dig through the binary file of E.T. the Extra-Terrestrial and fix the errors that made it an abomination of a title for the Atari 2600.

This is quite a feat in many ways. First off, you need to know the game well enough to understand where they problems lie. The Internet is a huge help in that regard as there’s no shortage of sources complaining about the game’s shortcomings. This turns out to be one of the articles strongest points as the author takes time to address the most common myths about bugs in the game. From there he goes on to discuss the problems that were actually fixed. Some are just general tweaks like the color fix listed above. But most of them are genuine improvements in the game play, like the falling fix which prevents E.T. from falling in this pit when his feet are obviously not anywhere near the edge.

So you couldn’t get your hard earned bucks back for a bummer of a game back in the day. But at least a few decades later you can fix the things that made it suck and play it through the way it should have been.

[via Reddit]

Filed under: software hacks

Light Graffiti is can be lots of fun if you have a decent amount of artistic ability, and a keen sense of timing. If you don’t have the necessary skills, you can always compensate by using Python-controlled servos to move everything automatically. The Python code can be found here, and makes use of the Python Image Library to process the images into a “drawable” form. A [pyMCU] with firmware capable of simultaneous servo control was used to move the laser fixture around.

One of the more difficult aspects of this experiment was getting the timing correct between each laser pulse. The timing routine involes a bit of geometry, calculating the distance between each using trig. As explained in the article, this may be a bit of overkill.  It still didn’t compare to the trig involved in a previous experiment drawing a circle with this laser-servo fixture.  Be sure to check out the video of this laser-setup in action after the break.  I’ve been quite pleased with the results, and look forward to what can be done with it in the future!

Thanks to [pyMCU] for letting me have a few of these boards to play with!

Filed under: digital cameras hacks, laptops hacks

It’s not called the infinity stapler, but we think it should be. This magnetic hack allows you to use a plain old stapler to fasten very large pieces of paper.

The limiting factor has always been the distance between the stapler’s hinge and where the staples come out. To get around this, the crimped connections between the base and the dispenser were drilled out. Larger holes were then drilled in both the top and bottom halves to accept a set of magnets. These were held in place temporarily with some tape while the super glue had time to set up.

The result is two halves which are placed on either side of the over sized paper. The magnets are responsible for aligning the staples with the die which bends them to their final shape. The whole process is shown in the video clip after the break.

Filed under: tool hacks

Check out this 3D printer (translated) which [Arkadiusz Śpiewak] has been working on. When sending in the tip about his project he made the important distinction that it isn’t finished, but he has reached that critical threshold where he has printed items with it.

He decided to go with a design that is sometimes referred to as an H-bot. If you’re completely unfamiliar with it, you may find this H-bot design article helpful. The gist of it is that this technique makes it so that the motors used to move the extruder along the X and Y axes are themselves stationary. One large timing (toothed) belt makes a circuit around the top of this cube in the shape of the letter H. This is a bit easier to see in [Arkadiusz's] rendered image found after the jump along with video of an early print test.

The Z axis uses two motors mounted along the bottom of the cube. These raise and lower the bead, instead of moving the extruder itself. All-in the printer should have a maximum object size of 30x30x30 centimeters. It’s being driven by a Smoothieboard, which was mentioned quite a bit when we were discussing using the RA driver board with a 3D printer.

Filed under: 3d Printer hacks

This tiny little scratch-built electric tricycle is a insanely powerful. Some might think you don’t need a crash helmet for testing a trike, but seeing the video after the break where [Ben Katz] is flying through a parking garage while slaloming between the support beams proves that this ride has some pep to it.

Looking through the presentation post linked above is fun, but when we started digging though the six build log posts we felt ourselves getting sucked into the project. It’s a delight every step of the way. It started with an aluminum box which will host the two rear wheels, drive train, motor, and battery. [Ben] decided to go with A123 Lithium cells, and after testing to see how many he could fit in the space available he started making choices on the motor and driver circuit. When he finally got his hands on the actual cells for the project he took on the fascinating process of constructing his own battery. Dozens of them were hot glued, then soldered together before being encased by placing them in soda bottles and hitting the plastic with a heat gun. And we haven’t even gotten into the bicycle hub-gear transmission system, disc brakes, differential, chain-drive, and motor… you see what we mean about sucking you in.

Oh, and in case you’re wondering this is not [Ben's] first electric vehicle build. Last year he was showing off his all terrain scooter.

Filed under: High Voltage Hacks, transportation hacks

[Chris] has been hard at work building a Heads Up Display into some Snowboarding goggles. We’re used to seeing the components that went into the project, but the application is unexpected. His own warning that the display is too close to your face and could cause injury if you were to fall highlights the impractical nature of the build. But hey, you’ve got to start somewhere when it comes to prototyping. Perhaps the next iteration will be something safe to use.

A set of MyVu glasses were added to the top portion of the goggles, which lets the wearer view the LCD output by looking slightly up. The display is fed by a Raspberry Pi board which connects to a GPS module, all of which is powered by a USB backup battery. In the video after the break you can see that the display shows time of day, speed, altitude, and temperature (although he hasn’t got a temperature sensor hooked up just yet). His bill of materials puts the project cost at about £160 which is just less that $250.

Filed under: wearable hacks