by Leo Rolph
Published on June 1, 2015
In this kit is everything you need to make, launch and relaunch water rockets, using 3D printing, household items and powered by Littlebits. This is a great project; the kit makes what is normally a time consuming and difficult task, fun and easy, allowing more time to be spent enjoying launches.
The Littlebits powered water rocket is great for all ages it teaches physics, mechanical knowledge, electrical understanding and aerodynamics; safely and in a fun way.
I wanted to keep this project simple, focusing on an easily made and fun project. We used only the parts we needed and really showed the power and potential of simple mechanics, imagination and some well-designed, hardy, seemingly indestructible and versatile Littlebits.
The launchpad is powered by one DC motor and uses standard garden hose attachments as the coupling to the rocket, I was pleasantly surprised to find the motor is easily strong enough to pull the lever to uncouple the rocket. The launchpad works first time every time, looks lovely and transports easily.
The parachute system works perfectly on all ground based tests, using an elastic band as tension to pull the door open and a servo to unlock the door. The servo is activated by a 9v battery sliding forward as the rocket tips over at apogee and making contact with Littlebits power module (after some testing this seemed like the simplest fail safe method). On our first test flight (which is often all you get with rockets) out of caution we didn’t pressurise the rocket enough and the parachute didn’t have time to eject properly, and it came crashing back to earth(though the door did open). Amazingly all the Littlebits survived! With a little more time and another launch I’m sure the parachute system will be successful.
The whole rocket is in a modular design for easy modification. We were very limited by our time and amount of Littlebits, but with Wi-Fi you could remote launch, use a countdown timer, have second stage ejection and much more. This project for me was finished right at the last possible moment.
The Rockets components are live on Shapeways
Also this site has some great info and getting the best results with your rockets. My rocket was really just simplified version to demonstrate the system.
Credits: Thanks Warren Tarboton for helping with the modeling. Thanks to Kav for assisting with the launch and thanks to my wife for giving me the time:)