Many of us made soda bottle rockets for science class. Some of us didn’t have that opportunity, and made them in the backyard because that’s what cool kids do. Water rockets work on the premise that if water is evacuated from one side of a container, the container will accelerate away from the evacuation point. Usually, this takes the form of a 2-liter bottle, a tire pump and some cardboard fins. [François Gissy] modified the design but not the principle for his water trike which reached 261 kph or 162mph.
Parts for the trike won’t be found in the average kitchen but many of them could be found in a motorcycle shop, except for the carbon fiber wrapped water tank. There wasn’t a throttle on this rocket, the clutch lever was modified to simply open the valve and let the rider hold on until the water ran out. The front brake seemed to be intact, thank goodness.
Powering vehicles in unconventional ways is always a treat to watch and [François Gissy]’s camera-studded trike is no exception. If you like your water rockets pointed skyward, check out this launch pad for STEM students and their water rockets. Of course, [Colin Furze] gets a shout-out for his jet-powered go-kart.
Thank you, [Itay], for the tip.
Continue reading “Trike with Water-Rocket Engine”
Rocket engines are undeniably cool. Experiencing the roar, seeing the fire, and watching the rocket blast off into the sky… what else can you ask for? Well, for [NightHawkInLight], a transparent rocket body is the answer.
Based on previous work by [Applied Science], he uses an acrylic rod as the rocket body and as the fuel. Bring a flame into the acrylic, apply oxygen from a canister at the other end of the body and voilà! The rocket engine starts nicely, and even better, the intensity of the burn can be controlled via the amount of oxygen provided.
Continue reading “Transparent Rocket Engine”
Testing rocket motors is a dangerous business, as they have an annoying habit of releasing all of that energy a little quicker than you might like. [Jeff Hopkins] knows this, so he made his own wireless rocket motor analyzer that allows him to trigger, test and monitor rocket motors from a safe distance. This involves more than just pushing a button and watching them go whoosh: his platform measures the thrust of the prototype over 90 times a second and transmits this data to him remotely for logging and later analysis. His current prototype can measure engines with up to 400 lbs of thrust. That is a lot, so it is a good thing that his rig can also remotely arm, fire or safe the motors, all over a 70cm wireless radio link that keeps him safely out of the way. It is also built of cheap parts, so if a RUD (Rapid Unplanned Disassembly) does occur, it won’t cost him much to rebuild and start again.
This project is part of a bigger plan: [Jeff] is looking to build a high-power launch platform that can launch an electronics platform high above the earth. Could this be the beginning of the race to be the first hacker in space? We shall see…
A liquid-fuel rocket engine is just about the hardest thing anyone could ever build. There are considerations for thermodynamics, machining, electronics, material science, and software just to have something that won’t blow up on the test rig. The data to build a liquid engine isn’t easy to find, either: a lot of helpful info is classified or locked up in one of [Elon]’s file cabinets.
[Graham] over at Fubar Labs in New Jersey is working to change this. He’s developing an open source, 3D printed, liquid fuel rocket engine. Right now, it’s not going to fly, but that’s not the point: the first step towards developing a successful rocket is to develop a successful engine, and [Graham] is hard at work making this a reality.
This engine, powered by gaseous oxygen and ethanol, is designed for 3D printing. It’s actually a great use of the technology; SpaceX and NASA have produced 3D printed engine parts using DMLS printers, but [Graham] is using the much cheaper (and available at Shapeways) metal SLS printers to produce his engine. Rocket engines are extremely hard to manufacture with traditional methods, making 3D printing the perfect process for building a rocket engine.
So far, [Graham] has printed the engine, injector, and igniter, all for the purpose of shoving oxygen and ethanol into the combustion chamber, lighting it, and marveling at the Mach cones. You can see a video of that below, but there’s also a few incredible resources on GitHub, the Fubar Labs wiki, and a bunch of pictures and test results here.
Continue reading “Open Source, 3D Printed Rocket Engines”
Robert’s Rocket Project has been going on for a long time. It has been around so long that you can go all the way back to posts from 2001, where he talks about getting his first digital camera! The site is dedicated to his pursuit of liquid fueled rocket engine building. It’s a great project log and he has finally come to the point where he will be testing his first flight vehicle soon.
His latest project is a 250lbf regeneratively cooled engine. It uses kerosene as the fuel, and liquid oxygen as the oxidizer. The neat thing is he utilizes the temperature change of the liquid oxygen expanding to cool the chamber and nozzle before being burned. This allows for a very efficient and powerful combustion of the fuel. He has some videos of testing it on his site, we just wonder why he doesn’t host them on YouTube or something…
Anyhow, there’s more than enough info on his site to try and recreate some of his experiments, but perhaps you should start here instead: How to Design, Build and Test Small Liquid-Fuel Rocket Engines.
[Graham] over at FUBAR labs took it upon himself to build a rocket engine. This isn’t a simple solid-fuel motor, though: [Graham] went all out and built a liquid-fueled engine that is ignited with a spark plug.
The build started off with a very small ‘igniter’ engine meant to shoot sparks into a larger engine. This engine is fueled with ethanol and air – not the best fuel for a rocket engine by a long shot but save and cheap enough to do a few serious experiments with.
To test out this small engine, [Graham] made a test platform out of aluminum extrusion to remotely control the fuel and oxidizer valves. The valves are controlled by an Arduino and XBee for remote operation and a telemetry downlink for measuring the fluid flow into the engine.
After he had some experience with pressure, plumbing, valves, and engines, [Graham] upgraded his fuel and oxidizer to gaseous oxygen and ethanol. With proper safety protocol in place, [Graham] was able to a series of three 3-second burns less than a minute apart as well as a single burn lasting nearly 5 seconds.
Even though [Graham] eschewed the usual stainless steel construction of rocket engines (his engine is milled out of aluminum), he demonstrated it is possible to build a real liquid-fueled rocket engine at home.
Most any rocket engine you’d find on a spacecraft – save for solid or hybrid rockets – use an engine system that’s fairly complex. Because of the intense heat, the fuel is circulated around the chamber before ignition giving a motor its regeneratively cooled nomenclature. This arrangement leads to a few complicated welding and machining processes, but surprisingly these obstacles can be overcome by simply printing a rocket engine on a 3D printer.
The current engine is quite small, but still fueled just like any other proper rocket engine that makes it into Earth orbit. The fuel is propane, the oxidizer is NO2, and the entire device is ignited with an automotive spark plug. Of course this was an expensive proposition; a motor with 12 pounds of thrust cost somewhere in the range of four figures.
Printing a rocket engine has a few advantages over traditional manufacturing techniques. [Rocket Moonlighting] explains that traditional techniques (mills, lathes and other heavy equipment) are bound by labor, material, and time. The costs of printing a rocket engine are only bound by the volume of the finished piece, meaning the most expensive engine per unit of thrust is the one that will fit in your pocket; scaling up means more efficiency for less cost.
There are a few videos up after the break showing the engine in action at full throttle, a few start and restart tests, and a test that involved throttling the engine. It’s an extremely impressive piece of kit, and hopefully [Rocket Moonlighting] will release the CAD source so we can make our own.
EDIT: [RM] tells me his engine cost less than $2000 to make. If just 10 people wanted their own engine from a ‘group buy,’ the price would drop by more than half. If you’d like your own 3D printed rocket engine, you might do well to drop [Rocket Moonlighting] a line.
Continue reading “3D printing a rocket engine”