Beautiful Arduino Fireworks Controller

A lot of designers have the luxury of creating things that aren’t supposed to explode. That’s usually easy. The trick is designing things that are supposed to explode and then making absolutely sure they explode at the right time (and only the right time). [JonBush] recently did a beautiful build of an Arduino-based fireworks controller. Seriously, it looks like a movie prop from a summer blockbuster where [Bruce Willis] is trying to decide what wire to cut.

[Jon] used a mega 2560 because he wanted to do the I/O directly from the device. His code only takes about 8K of the total program storage, so with some I/O expansion (like shift registers) a smaller chip would do the job. The device can control up to 8 sets of fireworks, uses a physical arm key, and has a handheld remote. It is even smart enough to sense igniter failures.

The front panel is a work of art and includes a seven-segment display made from Neopixel LEDs. The whole thing is in a waterproof case and uses optical isolation in several key areas.

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Puzzle Box is Rigged to Blow

[Sande24] needed a gift for his father’s birthday. He decided that rather than simply give his father the gifts, he would present his father with a unique challenge. The gifts are locked inside of a multi-stage puzzle box. This isn’t your average puzzle box though. This one is rigged to blow.

The puzzle box was designed to test his father’s reflexes, mind, and luck. The finished product looks sort of like a wooden crate made from particle board. The box contains three levels, each with its own gift and its own task to be completed.

With the lid opened, the first compartment and puzzle is revealed. Inside of the compartment were a new pair of gloves, meant to protect the father’s hands when working on the puzzles. The first puzzle is built into a sheet of wood with several custom-made levers. The levers must be moved into position in order to remove the wooden sheet and reveal the next level.

The first lever triggers a home-made detonator that eventually lights a series of fireworks placed around the box. You need to solve the puzzle box fast enough to prevent the fireworks from destroying the gifts that lay inside. [Sande24] was unable to legally purchase fuses where he lived, so he had to make his own.

The second level held a gas mask, also meant to protect the father from the booby traps of this mysterious box. This level, also made from a sheet of wood, has nine squares drawn on it. Each square is labeled with a different number which goes into solving a mathematical function (x^5-25x^4+233x^3-995x^2+1866x-1080 = 0). The solution to the function would reveal the safe path to be used to cut the wooden platform in half. Unfortunately [Sande24’s] father cut the wrong squares and released a huge amount of vinegar into the box. Oops.

The bottom level contained the final puzzle and the locked treasure compartment locked with an ordinary padlock. To find the key, another puzzle had to be solved based on a series of wooden levers labeled with different shapes. The shapes provided clues to the order in which the levers should be pulled. Once the levers were moved into position, two compartments were unlocked. One of them contained the key to the treasure box. The other contained another booby trap which would set off more fireworks, destroying the final gift of four cans of Kuld beer. That’s a lot of work to get a a few cans of frothy beverage!

[Thanks Ellery]

Retrotectacular: The Science of Derailing Trains


Look closely above and you’ll see there’s a section of track missing. There are actually two, a section from each side has been plucked out with a pair of eight-ounce plastic explosive charges — and yet the train keeps barreling onward. The World War II era reel is demonstrating some military testing of the effect of damaged tracks on a train. The amount of missing track the train can stand up to came as quite a surprise for us!

The test setup itself is neat. An old derelict locomotive is used. It, as well as a number of trailing cars, is pushed by a functioning engine from behind. Once up to about 26 MPH the pusher stops and the rest keep going. There are many tests, starting with just a few inches of track missing from one side. This gap is increased, then gaps are added both sides, then the two sides are offset. Even a 5-foot gap is crossed easily by the locomotive. The weak link turns out to be the empty cars. We suppose their mass is small enough that they can’t rely on inertia to keep them on the straight path.

If you don’t appreciate the destructive nature of this Retrotechtacular installment, you can still get your train fix. There is another offering which shows off the modernization of a signaling system.

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Boom goes the dynamite – murals made with precision explosives


[Alexandre Farto] is known for some off the wall art displays, but his newest work takes the phrase literally. Using precisely placed explosive charges, he has been sculpting portraits and other murals on walls in various places around London.

The detail at which he is able to produce these images is incredible, considering he is blowing chunks of plaster and brick from walls to form them. We can only guess as to how much preparation time is required to finish even one of these images, let alone to amass the stunning portfolio he has put together.

He has also recently teamed up with musical artist [Orelha Negra] to produce a cool video of his work as it was being sculpted, which is certainly worth the three minutes it takes to watch. The video, embedded below, is chock full of slow-motion shots of the demolition/sculpting in progress.

If you have a few minutes, be sure to check out his site to take a look at some of his work, we think you will be impressed.

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High explosives PC case


[Ilias] let us know about his new HTPC case mod.  He took a surplus Ammo-case and with a bit of work turned it into a livingroom eye-sore masterpiece. His build has some nice touches, including a slot-fed DVD player, switch-based fan control, and key-and-button “nuclear launch” type power-on controls.

A few things to learn from this project: Cleanly cutting holes in a steel case for the connectors is tough.  You can see that [Ilias] did a pretty good job with it and in several cases used rubber gaskets to cover the rough edges. Secondly, the slot fed DVD had to be mounted upside-down.  We assume this will be fine, but we’d like to hear a follow-up after a few years of heavy use. Finally, the GFAF (girlfriend acceptance factor) ran very close to critical on this build as [Ilias] didn’t clean up the metal shavings on his porch and ended up with rust stains everywhere.

Case mods are an enjoyable hobby. We hope this will inspire you to take the leap.  If you do, don’t forget to send your completed project into our tip line.