4 ms·

3D printed rocket – operational tests

60 points by iamwil 14y ago

deleted 14y ago
[deleted]
kordless 14y ago
What part of the rocket is printed? I see a lot of metal there.
- a1k0n 14y ago
  This post here seems to be more informative: http://rocketmoonlighting.blogspot.com/2011/03/what-its-all-about.html http://rocketmoonlighting.blogspot.com/2011/03/what-its-all-... To save you a trip to Wikipedia, DMLS is Direct metal laser sintering -- 3D printing with metal.
  - fosk 14y ago
    This an example of such a printer: http://production3dprinters.com/slm/direct-metal-slm http://production3dprinters.com/slm/direct-metal-slm
ChuckMcM 14y ago
That was interesting. I feel like I've seen an X rated movie that was edited and pixellated to make it PG-13. Lots of tantalizing bits, not a lot of narrative, and details hard to ferret out. The basic notion that you could use metal sintering to create a rocket combustion chamber that included the cooling jacket is pretty neat. That lets you run reasonably energetic fuels without having exotic materials (tungsten for example). I can also see why going too far down that path might lead to untoward interest by third parties.
- clayrichardson 14y ago
  Suppose someone wanted to take this hobby farther down the path, and start a rocket company similar to SpaceX. How would one avoid negative attention in doing so?
  - ChuckMcM 14y ago
    Well there is a pretty large amateur rocketry group in the Bay Area [1] that goes out to the Blackrock desert and launches rockets. Generally such clubs are great resources for understanding the regulations and if pursuing things professionally the requisite licensing. I was related a story about how the Bureau of Alcohol Tobacco and Firearms (BATF) stopped one team from launching because they had used a solar tracker attached to steerable fins to keep the rocket on track, the story went that once you had it tracking a heat signature with steerable fins it went from being a model rocket to a munition. I can't vouch for accuracy of the story but the teller was someone I respect and is quite an enthusiast so I give it a good chance of being basically true. So generally one considers the various elements of creating a rocket propelled munition and if you got too close to describing how someone could build one, I would not be surprised in the least if that person was approached by the BATF or the FBI asking you to limit what you publish. Or approached by people seeking to build such a device from 'scratch.' Even doing something as simple as hobby robotics I've had folks email me out of the blue on how to create a circuit that would let you activate a switch remotely but was hard to jam. It can conceivably be used for robotics sure, it can also be used for ill. I generally point people to Horowitz and Hill's Art of Electronics and tell them its all in there (which it is, but you have learn it to use it) but perhaps out of a surplus of caution I don't design such things for folks. [1] http://science.kqed.org/quest/video/amateur-rocketeers-reach-for-the-stars/ http://science.kqed.org/quest/video/amateur-rocketeers-reach...
jlgreco 14y ago
Now we just need a printed turbopump.
RobertHoudin 14y ago
Looks interesting, but could somebody please explain this like I'm 5?
- ChuckMcM 14y ago
  Well it is rocket science. I can strongly recommend any version of "Rocket Propulsion Elements: And Introduction to the Engineering of Rockets" Knowing calculus when you read it is helpful but not essential. That said, rocket engine design is a tradeoff between how much energy you generate in the combustion chamber and your ability to direct the resulting hot gas in the direction you want it to go. Highly temperature resistant materials like ceramics can take a lot of heat, but they don't have a lot of tensile strength, things like metals which are very tough generally become weaker the hotter they get. Combined with the fact that combustion chamber shape determines how the gases will burn, and you find yourself trying to design something that is very durable, can withstand significant pressure, and can take a lot of heat. Model rocket engines basically consume themselves as they burn being their own combustion chamber, but liquid or gaseous fueled rockets have to deal with the heat. The kicker is that if you don't get enough energy in the combustion chamber, you can't generate enough thrust to counteract the force of gravity so you can't even get off the ground. The Space Shuttle's engines use tubing that runs through the engine 'bells' that cryogenic liquid runs through prior to being burned as fuel. This keeps them cool enough to contain the engine burn without melting or losing structural stability. That isn't something someone can build on a 'whim'. This guy made something similar using a 3D printing process on metals. Assuming that the metal's tensile strength is sufficient post printing, this sidesteps a huge barrier to amateurs making liquid/gaseous fueled engines.
anovikov 14y ago
Will be curious to see the whole stage printed :) Of course electronics, wiring, probably ignitors, electric actuators and some other stuff can't be printed, but it removes a lot of pain from the process.

60 points by iamwil 14y ago

deleted 14y ago

[deleted]

kordless 14y ago

What part of the rocket is printed? I see a lot of metal there.

a1k0n 14y ago
This post here seems to be more informative: http://rocketmoonlighting.blogspot.com/2011/03/what-its-all-about.html http://rocketmoonlighting.blogspot.com/2011/03/what-its-all-... To save you a trip to Wikipedia, DMLS is Direct metal laser sintering -- 3D printing with metal.
- fosk 14y ago
  This an example of such a printer: http://production3dprinters.com/slm/direct-metal-slm http://production3dprinters.com/slm/direct-metal-slm

ChuckMcM 14y ago

That was interesting. I feel like I've seen an X rated movie that was edited and pixellated to make it PG-13. Lots of tantalizing bits, not a lot of narrative, and details hard to ferret out. The basic notion that you could use metal sintering to create a rocket combustion chamber that included the cooling jacket is pretty neat. That lets you run reasonably energetic fuels without having exotic materials (tungsten for example). I can also see why going too far down that path might lead to untoward interest by third parties.

clayrichardson 14y ago
Suppose someone wanted to take this hobby farther down the path, and start a rocket company similar to SpaceX. How would one avoid negative attention in doing so?
- ChuckMcM 14y ago
  Well there is a pretty large amateur rocketry group in the Bay Area [1] that goes out to the Blackrock desert and launches rockets. Generally such clubs are great resources for understanding the regulations and if pursuing things professionally the requisite licensing. I was related a story about how the Bureau of Alcohol Tobacco and Firearms (BATF) stopped one team from launching because they had used a solar tracker attached to steerable fins to keep the rocket on track, the story went that once you had it tracking a heat signature with steerable fins it went from being a model rocket to a munition. I can't vouch for accuracy of the story but the teller was someone I respect and is quite an enthusiast so I give it a good chance of being basically true. So generally one considers the various elements of creating a rocket propelled munition and if you got too close to describing how someone could build one, I would not be surprised in the least if that person was approached by the BATF or the FBI asking you to limit what you publish. Or approached by people seeking to build such a device from 'scratch.' Even doing something as simple as hobby robotics I've had folks email me out of the blue on how to create a circuit that would let you activate a switch remotely but was hard to jam. It can conceivably be used for robotics sure, it can also be used for ill. I generally point people to Horowitz and Hill's Art of Electronics and tell them its all in there (which it is, but you have learn it to use it) but perhaps out of a surplus of caution I don't design such things for folks. [1] http://science.kqed.org/quest/video/amateur-rocketeers-reach-for-the-stars/ http://science.kqed.org/quest/video/amateur-rocketeers-reach...

jlgreco 14y ago

Now we just need a printed turbopump.

RobertHoudin 14y ago

Looks interesting, but could somebody please explain this like I'm 5?

ChuckMcM 14y ago
Well it is rocket science. I can strongly recommend any version of "Rocket Propulsion Elements: And Introduction to the Engineering of Rockets" Knowing calculus when you read it is helpful but not essential. That said, rocket engine design is a tradeoff between how much energy you generate in the combustion chamber and your ability to direct the resulting hot gas in the direction you want it to go. Highly temperature resistant materials like ceramics can take a lot of heat, but they don't have a lot of tensile strength, things like metals which are very tough generally become weaker the hotter they get. Combined with the fact that combustion chamber shape determines how the gases will burn, and you find yourself trying to design something that is very durable, can withstand significant pressure, and can take a lot of heat. Model rocket engines basically consume themselves as they burn being their own combustion chamber, but liquid or gaseous fueled rockets have to deal with the heat. The kicker is that if you don't get enough energy in the combustion chamber, you can't generate enough thrust to counteract the force of gravity so you can't even get off the ground. The Space Shuttle's engines use tubing that runs through the engine 'bells' that cryogenic liquid runs through prior to being burned as fuel. This keeps them cool enough to contain the engine burn without melting or losing structural stability. That isn't something someone can build on a 'whim'. This guy made something similar using a 3D printing process on metals. Assuming that the metal's tensile strength is sufficient post printing, this sidesteps a huge barrier to amateurs making liquid/gaseous fueled engines.

anovikov 14y ago

Will be curious to see the whole stage printed :) Of course electronics, wiring, probably ignitors, electric actuators and some other stuff can't be printed, but it removes a lot of pain from the process.