Holiday Hacks

365 Articles

Make A Cheap (And Dangerous) Automated Flamethrower

October 16, 2015 by 22 Comments

Nothing lights up the night like a quick blast from a flamethrower, but there is a reason why you can’t buy them in the Halloween decoration aisle at Target. They are dangerous, for fairly obvious reasons. [Erco] seems to have no particular fear of death, though, and he shows how you can build a simple flamethrower with a small candle, a servo, Arduino and a can of hairspray. Tresemme Extra Strong Hold, in particular, although we don’t think the exact type matters that much. All he did was to mount the candle in front of the hairspray, then mount the servo so the arm presses the spray head down. The candle does the rest, lighting the highly flammable propellant in the hairspray to produce the flamethrower effect. [Erco] is using four of these, which are co-ordinated to fire in time with music.

This one seems a bit risky. Servos have a habit of locking, and there is nothing stopping these from locking in the open position, or sticking there if the Arduino crashes. A relay or other switch that reverts to an off position when the power is removed would have been more suitable here. Secondly, there is no emergency off switch. [Erco] has wired the Arduino up next to the flamethrower itself, so you are going to have to reach in to disconnect it. That is risky enough, but he also tried a 4-way configuration that would have been impossible to disable in the event of a problem (shown in the accompanying images). Thirdly, there is no fire protection between the can of hairspray and the open flame, so if the spray head melts or fails from the heat, it’s game over. Finally (and most importantly), where are the fire extinguishers? We’d like to hear how you’d build this with safety in mind. Let us know in the comments below.

We’re big fans of flames and explosions: we’ve have seen a couple of Survival Research Laboratory shows and were blown away by their destructive pyrotechnics. But, as SRL head Mark Pauline said in a recent talk, “when things blow up at an SRL show, it’s on purpose”.

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BOO! Teach Arduino Basics With This Fun Ghost

October 9, 2015 by 9 Comments

Halloween is just around the corner, and the spooky themed tips are just starting to roll in. If you’re looking to one-up the basic store-bought decorations, and maybe teach your kid the basics of an Arduino while you’re at it — why not build a Peek-A-Boo Ghost!

Using an Arduino, two servo motors and an ultrasonic distance sensor it’s pretty easy to make this cute little ghost that covers its eyes when no one is around. They’re using cardboard for the ghost, but if you have access to a laser cutter at your hackerspace, you could make it a lot more robust using MDF or plywood.

When the ultrasonic distance sensor senses someone coming towards it, it’ll trigger the arms to move — though it’d be easy to add a small speaker element too and get some spooky music going as well!

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Halloween Hood Has Hideous LED Gaze

October 8, 2015 by 12 Comments

Looking to create fear and dread with your Halloween costume? [Becky Stern] over at Adafruit has you covered, with her tutorial on building a mystical hood with LED eyes, perfect for your next Jawa, Black Mage, or Orko costume.

This creepy-looking creation is based around a Gemma controller driving two NeoPixel Jewels, small circular RGB LED boards. The Gemma drives the boards to slowly fade on and off for the required creepy eye effect, but it would be easy to create other lighting patterns.

Speaking of patterns, the tutorial also includes a sewing pattern for the hood, and plans for a 3D printed battery holder that would make the whole thing very easy to carry. If the eyes aren’t enough, how about adding an LED magic staff to complete your creepy ensemble? Or perhaps some light-up dinosaur spiky plates?

Do you have any good Halloween costume hack plans? Let us know in the comments, and we’ll put together a list of the best closer to the hideous day.

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Hand Cranking The Malevolent Mechanical Pumpkin

October 6, 2015 by 2 Comments

Meet Marty. He’s a pumpkin that has been fitted out with a moving eyes, tongue and an expression of malevolent glee. You would probably assume that this is all driven by servos, right? Nope: Marty is driven by an old-fashioned crank mechanism, designed and built by [Ben Brandt].

He wanted to make something that could be driven by a hand crank. Of course, there is nothing stopping you from throwing a motor on the back to drive the mechanism, but [Ben] wanted the internals to be fireproof so he could light it with a candle. His mechanism, built from old bits of wire and sheet metal, is not flammable or adversely affected by heat like a motor and power supply would be. He succeeded admirably, and he has also done an excellent job of documenting the process to providing handy tips on creating a mechanical pumpkin-based monstrosity.

Those hackers down with a little electronic wet work you should start building their LED-integrated Jack-O-Lantern now. These things take a lot of time turn out.

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Apple Cider Press Is Just In Time For Fall

October 4, 2015 by 35 Comments

Do you like hacking? Do you like apple cider? Do you like ceiling fans? If you answered “yes” to any of those questions, then boy do we have the project for you! [Lou Wozniak] has an awesome tutorial for building an apple cider press using a ceiling fan motor and a handful of items available at your local hardware store.

The build is pretty simple in concept but complex in execution, and [Lou] does a fantastic job of covering every step in detail in his two project videos. The project has two main components: the grinder to decimate the apples and create a juicy, pulpy soup, and the press to extract the juice. The grinder is powered by the fan motor, while the press uses a screw-drive connected to a power drill, and then a ratchet to squeeze out every last drop.

Eager for more ceiling fan motor goodness? You’re in luck! Apparently [Lou] is a master of repurposing fan motors, and we featured a pottery wheel he made with one a while back.

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HC-SR04 Isn’t The Same As Parallax PING))) But It Can Pretend To Be!

September 22, 2015 by 8 Comments

“It’s only software!” A sentence that strikes terror in the heart of an embedded systems software developer. That sentence is often uttered when the software person finds a bug in the hardware and others assume it’s going to be easier for fix in software rather than spin a new hardware revision. No wonder software is always late.

[Clint Stevenson] is his own hardware and software guy, as are most of us. He wanted to use the less expensive HC-SR04 ultrasonic rangefinder in a prototype. Longer term he wanted to have the choice of either a Parallax PING or MaxBotix ultrasonic sensor for their better performance outdoors. His hardware hack of the SR04 made this a software problem which he also managed to solve!

[Clint] was working with the Arduino library, based on the Parallax PING, which uses a single pin for trigger and echo. The HC-SR04 uses separate pins. Originally he modified the Arduino library to accept the two pin approach. But with his long term goal in mind, he also modified the HC-SR04 sensor by removing the on-board pull-up resistor and adding a new one on the connector side to combine the signals. That gave him an SR04 that worked with the single-pin based library.

We’ve seen Parallax PING projects for sensing water depth and to generate music. These could be hacked to use the HC-SR04 using [Clint’s] techniques.

[Arduino and HC-SR04 photo from Blax Lab]

Robot Chicken

T-1000C: This Time The Chickens Will Be Back

April 5, 2015 by 20 Comments

For whatever reason the city [Jenslabs] lives in decided it was a good use of taxpayer money to make some giant twig chickens and put them on the boulevard in front of his house. So he decided to spruce them up a bit with some electronics.

We’re still unsure why they did this, but [Jens] recognized them for what they truly are. T-1000C — the chicken edition. Giant robot chickens sent from the future to keep an eye on [Jens] to make sure he doesn’t stop ChickenNet. Naturally they needed glowing red eyes.

Fully expecting all his hard work to be thrown out eventually, [Jens] built the upgrades out of cheap components. A few LEDs, some transistors, resistors and a LDR (light dependent resistor). That way the eyes only glow at night.  And to waterproof it all, he wrapped it in good ‘ol duct tape.

For more fun Easter hacks, why not add some LEDs to your decorated eggs?