[Valentin] is the MacGyver of model rocketry, building a small rocket out of three items many people have hanging around the house. Cat litter, matchsticks, and a ballpoint pen are the raw materials that he rounded up before setting to work on the build.

The housing of the ballpoint pen will act as the body of the rocket. [Valentin] stuffed the tip of the pen with cat litter, creating the first part of the fuel chamber. Next, the heads of the matches were very carefully muddled into a fine powder which fills the bulk of the pen housing. Finish this off with another plug of cat litter and you’re almost done. The final step is to drill a hole through the plug layer at the tip of the pen, creating a nozzle to focus the force as the fuel burns.

From the videos we’d say there needs to be some work done as far as rocket guidance, but the solid state fuel certainly does work. Just remember to make your personal safety the first priority when working with combustibles like this!

Wondering how to launch something like this? Here’s a way to make your own igniters.

If you thought you had a cool tree house as a kid, think again. Tasked with landscaping his back yard and building a tree house for his son, [Jon] decided to go all out and build him a rocket ship instead.

Rising 15 feet into the Seattle skyline, the tree house known as the Ravenna Ultra-Low-Altitude Vehicle (RULAV), is sure to be the envy of every kid in the neighborhood. [Jon] and a friend worked for well over a year on their creation, welding, grinding, painting, and riveting their way along. After the structure was built, they fabricated some custom PCBs, using them to build the ship’s 14 control panels. The entire operation is controlled by a custom OS built to run on the three ATmega MCUs that manage operations.

Not content with just a handful of knobs and switches, the ship contains over 800 LEDs among its laundry list of electronics goodies. Compressed air is used to shoot water from positioning “thrusters”, while a paint mixer spins under the ship to simulate the rough and bumpy nature of space travel. The simulated launches are capped off with plenty of authentic NASA-style audio and a sub woofer that gives everything a deep, resonating rumble.

The project is truly amazing, and a ton of work went into every little detail in order to make this the most spectacular tree house ever seen. [Jon] definitely takes the award for “Coolest Dad Ever” for this build, even we’re jealous!

The pictures certainly don’t do it justice, so be sure to check out the video below for a quick introduction and demo of this awesome project.

Thanks to [Jeremy Elson] for the tip.

[Ken] sent us his Instructable in which he used radio telemetry to monitor the status of his air-powered model rocket through a series of launches. His setup is centered around an Arduino IDE-compatible board that looks to be about the size of a Boarduino, but has the benefit of an embedded 915 MHz radio module. The vendor he used also sells a good handful of add-on modules which he used for his in-flight recording, including a barometric pressure monitor and a 3-axis accelerometer. During flight, the rocket constantly sends data to a base station, provided it stays within radio operating range.

For is initial tests, [Ken] launched his rocket four times, getting usable data on half of them. He found out some interesting things about his model rocket, including the fact that it creates a maximum launch force of 60 Gs. He has plans to revise his setup in the future, such as lightening the battery load as well as adding a high-G analog sensor for recording the forces at take off. This kit, or a more reasonably priced clone, would make for a great addition to any rocket buff’s inventory.

If this is meant for a model rocket it must be the biggest we’ve ever seen. [Scott] and [Trevor] took on the task of building a rocket attitude control system after reading about some research on the topic. But that researcher only tested the theories using simulations so they set out to build their own. The prototype above has a tank of compressed Nitrogen which can hold up to 3000 PSI. You can begin to understand why this needs to be used with a big rocket. The pressurized gas is connected through a regulator to four valves which feed nozzles around the circumference of the fuselage. An Arduino takes readings from a gyroscope and actuates the gas valves via a relay board.

You can check out the test rig in the video after the break. The prototype is suspended horizontally from a wire and its orientation held at one position by the system. There’s also a paper (PDF) if you’re interested in the equations that went into the stabilization control. This system would have been right at home on that huge sugar rocket we saw back in October.

[cmwslw] built a soda-bottle water rocket that uses the ignition of oxyhydrogen gas to quickly expel the water, as opposed to the usual compressed air and water mixture. His project contains excellent documentation with photos and it builds on other articles he’s written about generating the flammable HHO gas used to launch his craft into the skies. Every aspect of this project uses items most of us have at home or could score cheaply at most hardware stores.

We love seeing projects that re-purpose everyday materials into something fun. Just be sure to dodge the missile pop bottle as it speeds back to Earth!

[Stephan Jones] has an easy method for making your own model rocket engine igniter. The solid state motors used in this hobby consume one igniter with each electrically triggered launch. Whether you’re making your own motors or not, this construction technique should prohibit you from every buying an igniter again. The process involves bending some nichrome wire around a paper clip, adding some structural support to the leads using masking tape, and insulating the business end with a quick dip in paint.

Now would be a good time to send us your launchpad hacks. All we’ve seen so far is a launchpad for water rockets.

[via Make]

We’re told that this rocket is sugar powered. It’s quite a bit bigger than the homemade sugar motors we saw last week and it makes for quite a show. [Thanks Estqwerty]

Wooden PC construction

The finished look of this wooden PC case seems very familiar to us but we’re not sure we’ve seen pictures of the build process(updated link, sorry [Jeff]) before. There’s something extremely satisfying about how well its creator works with a file. [Thanks Anders]

Working on top

We never realized that this job existed, but if you repair communication towers it’s a heck of a climb to work. The video of a two-man crew climbing a 1600 foot tower is one of the most interesting we’ve seen this year. [via Blogging Protagonist]

Lego typing machine

[Dougal's] typing machine types his name… over and over again. An interesting little piece of mechanical engineering, we’d have to think for a while to decide the best use for this little guy. [Thanks Chris]

Typing on a different type of keyboard

Here’s another typing machine but this time it’s not a keyboard and not purely mechanical. Pictured is one of the performers in an old equipment ensemble performing with whining stepper motors, speech synthesis, an other antiquated noise-makers. [Thanks Mike]

[KoD] and [Navic] are building solid propellant motors using sugar and potassium nitrate. They cook up the two ingredients along with water and a bonding agent. They find that corn syrup is particularly good for bonding and that cooking the strange brew is more of an artform than science. Either way, the video after the break is proof of the dangers involved in this hobby. Testing the engine thrust with a bathroom scale ends badly for the scale.

There is something satisfying about the ingenuity that goes into the materials. For a casing they’re using PVC pipe, and forming a cone to focus the thrust by using a what amounts to plumber’s epoxy putty. The capping agent for the finished motor is ground up kitty litter.

This is an interesting read, but for now we’re going to stick to water rockets.

The Copenhagen Suborbitals are now within one week of their first launch. We looked in on the non-profit and non-secretive space program back in March but we had no idea the group had a frickin’ submarine at their disposal. What you see above is the rocket on its floating launch platform. The submarine will haul it out into the Baltic Sea for launch. There’s not much room in the craft for an astronaut but it will be a horrifying an exhilarating flight. According to the spacecraft page the human payload will be in a half-sitting, half-standing position looking up through an acrylic nose dome. This first launch will not be manned, but once they get through the tests this will be one crazy ride.

Hackers [Navic] and [K.o.D] have fitted an Arduino Pro Mini and an array of components into an off the shelf rocketry kit to create a guided model rocket, taking the whole idea of Arduino-based space technology to another level

The Arduino reads signals from internally mounted accelerometers, and adjusts balsa fins (via 4 micro servos) to correct the rocket’s flight path. Due to the nature of model rocketry, the active guidance is limited to the 3 seconds that the rocket is traveling upwards. A valiant effort nevertheless. Videos of the rocket’s maiden voyage, and a system check after the break.

[Atlantageek] sent in a missile launcher project that he threw together. For Christmas he received a Chumby One and a ThinkGeek USB Rocket Launcher as gifts (lucky dog). Neither of these toys are “played with” in the traditional sense as much as they become centerpieces of your next hack. In that spirit, [Atlantageek] immediately wrote a widget to control the launcher via the Chumby. The side effect of driving his cat bonkers was an unexpected bonus.

Check out the launch video below. It’s too bad that they went with a commercial solution for servo control rather than building it themselves (especially considering it is an embedded systems class). But it is a nice build none the less. Now they need to add some imaging equipment to the rockets and they’ll be in business.

This jet powered carousel is brought to you by the Madagascar Institute. They convene, or collide, to create large scale art, sculptures, and rides. This one seems to fit the last definition. The two gentlemen are strapped to a jet powered carousel. It actually looks pretty fun, but we would have been needing some fresh shorts after the jet bursts into flames near the end. He didn’t seem too concerned, he wasn’t screaming and flailing his arms at least.

Have you ever wondered how high or how fast a model rocket goes when you launch it? [sprite_tm] did, so he decided to build a low cost, lightweight data logger that he could fit into the nose cone of his rocket. To keep the circuit small, he built it around the popular ATtiny13 microcontroller. The microcontroller collects data from a Freescale MMA7260, a 3-axis accelerometer that he extracted from a third-party Wii nunchuck controller. After the microcontroller collects the data, it’s stored in 32K of EEPROM on a 24C256. All of this is powered by a small 3.6v Li-ion battery, which is the largest part of the circuit. If this sounds like something you’d like to make, he has detailed instructions along with the software used available on his site. While we don’t launch a lot of model rockets here, we may soon start just so that we have an excuse to build this.

[Gabe] sent in this project summary from his rocketry club’s yearly project(pdf). The goal was to build a rocket that would go up to about 800 meters and eject a robot that would pilot itself to a destination on the ground for re use. There’s tons of great information from what hardware is in the robot to hardware design for the ejection mechanism.  There are great pictures of the final build, not so many of the construction itself. The project seemed to go well until EMI problems caused everything to fail during flight.  If you’re interested in seeing more from the club, check out their site (translated).