I am thinking the bigger the jig, the easier it is for misalignments to happen and error to compound. Remember, these machine work by piling up a lot of little layers like a deck of cards, think of the problems if a couple of those layers are a bit out of position in something like the wall of a piston cylinder. If you are working in 4 micron layers, then your positioning system has to be good for that, but everything is reference off the beacons, not the work piece. Even normal temperature swings could easily knock things out of alignment in a large jig operating at a fine enough resolution.
Skunk Works unveil SR-72 concept
- Thread starter colay
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John Fedup
The Bunker Group
Sorry for the one-line reply but your internet comment is right on!The unfortunate thing about [The internet] is what you meant
Off topic but would this sort of printing be easier to manage in vacuum ? Or even microgravity? Could space manufacturing work ?
Depends I'd say probably but the thing is no one has invested in the infrastructure necessary to begin manufacturing in orbit. SpaceX getting mostly or fully reusable which seems likely in the next few years would make it quite possible to do. Then we would need to begin testing and such. Also they are already testing making parts on orbit.
Lots of cool things can be done in vacum and in in space. Part of the problem is we just haven't invested in it yet. To many flags and footprints not enough taming of the frontier.
Shanesworld
Well-Known Member
Funny you say that. I'm building a powder printer at the moment to go inside a vacuum (near vacuum) box at the moment.
Its months away from even working as a printer (excuses include work, study and the missus).
Some people I have talked to, that know alot more than me, say it will make stronger more consistent parts, others say it won't make a difference and one guy reckons all the by metallic components will react different and I might kill the printer. But doesn't seem like to many people have tried it yet.
Thermal management of the binder (plan on using a two pot epoxy or polyurethane) is one issue.
However in terms of 3D printing, Electron beam or laser probably rectifies that issue.
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Tough question, there are a lot of different technologies for doing this and some gain advantages in different environments, while others can’t be used at all.
With most a vacuum should be advantageous because it would reduce porosity, especially critical in metals and any amorphous solid. However, most of the current systems wouldn’t work in microgravity because they depend on gravity to keep the bulk of the fabrication material under control so it doesn’t blocking the beam path.
Heh there was a combat module for the Soviet Salyut-7 during the Cold War, that was supposed to carry two space-space missiles. Then there were the Almaz projects in the late 80s, Almaz-1 was a satellite bomb, intended to destroy other satellites, and Almaz-2 was a satellite with a 20-mm cannon on it, for the same purpose. Weaponizing space was always a question of when, not if.
.... and how soon it would leak out that people weren't playing in the spirit of those agreements
NASA will be launching a plastic direct deposit machine shortly into orbit. So those types (and there are direct to metal versions) would work but they generally have limited size.
3D printing will however open up a whole new world in terms of aerospace with materials, parts etc being more complex and made out of materials previously extremely difficult to work with. In terms of hypersonics, it should make things far easier and cheaper (relatively, from not viable to viable).
Looking at the development that had to be pioneered with the SR-71 with titanium, the SR-72 will have to make more significant gains in material science, fabrication and production.
With hypersonic developments your in a weird world where space becomes a bit more reachable. We will I think see hypersonics on 5 and 6th gen aircraft. Hypersonic aircraft launching hypersonic weapons playing in the same sort of space as orbital launched weapons. The difference between orbital and hypersonics may be less than the difference between hypersonics and regular aircraft.
the difference has exponentially shortened IMO, eg when wookie and I were involved there was a correlation established with another technology which fundamentally had no direct association with aerodynamics
within this decade.....
I saw an interview with one of the Cosmonauts about that - apparently they tested the cannon once they were done with the module on the grounds they were a bit concerned about what effect the cannon would have. I think it was a bit bigger than a 20mm as well, but either way, it beat "no cannon" in a cannon fight.
Ian
I go away to Dayton for a week and the board has exploded...
But for a coffee table talk (non classified) summary:1) re the topic on confidence: There are no issues. The technical risk is extremely low following a few Tango Bravos. Can they screw it up?... Sure, but (my obs) there is a general feeling of purpose (if not relief) at doing something we know how to do. I call this F-35 fatigue or "please GOD, not another F-35 bulkhead".
2) The Mach 6 wind tunnel is sweet!!!! We are talking massive volumes of air flow.
3) Who said Mach 6 needs to be obtained at high altitude??
That would make it a spacecraft and that is a NASA mission,. :lol3 .... In other words, it is an assumption and word to the wise, not everyone in DARPA knows how to do stuff. People in commercial companies (like Lockheed Martin) might be experts in their field too and who is to say their security might not be more stringent then Federal Assets?4) Credible threats? There are no chemically driven platforms that can intercept an actively aware hypersonic platform (that I know of). DEW can be managed, as the most plausible threat is airborne DEW. Ground based DEW is going to have some serious issues (as you know).
5) Some people commented on compressive lift: It doesn't have to look like an XB70 to be a wave rider... google wikipedia and it gives a good list of hypersonic shapes.
6) Most of the conversations centered around the same Tango Bravos that would reduce the tyranny of distance for Cargo Operations. Lets double the C-17's efficiency and then followed onto F-22 replacement tech. I know, boring stuff... the SR-72 (itself) is a non-issue. The technologies coming out of that program is the interesting point.
e.g. Can they be used for cargo operations, Growler, etc, etc. Growler made me blink as I was not aware of the full electronics payload capacity (off the top of my head). I immediately thought of you guys as your Growlers are not sitting on a carrier deck exposed to salt air.
7) I wish you were there GF, it would have been fun
cheers
W
7) I wish you were there GF, it would have been fun
cheers
W
Believe me, I'd be there in a heartbeat under different circumstances ....
Yep. There was also this thing: [ame="http://en.wikipedia.org/wiki/Soviet_laser_pistol"]Soviet laser pistol - Wikipedia, the free encyclopedia[/ame]
I saw a photo of it on iirc englishrussia, but I'm too lazy to find it.
Iirc it was in "Battle for the Skies" that there was info on Soviet space weapons.
EDIT: Photo here.
http://www.geraldika.org/06_2007_10.htm
EDIT2: Actually you're right, it was a 23mm cannon. Here's the wiki: [ame="http://en.wikipedia.org/wiki/Almaz"]Almaz - Wikipedia, the free encyclopedia[/ame]
This is interesting "OPS-2 (or Almaz 101.2), announced as Salyut 3, was launched on June 25, 1974. The crew of the Soyuz 14 spacecraft spent 15 days aboard the station in July 1974. A second expedition was launched toward OPS-2 in August 1974, but failed to reach the station. The station successfully remotely test-fired an onboard aircraft cannon at a target satellite while the station was unmanned. Salyut-3 was deorbited in January 1975."
EDIT3: I should stop derailing this thread...
Acoustics? Im curious.
Just playing around with some numbers.
Just some napkin calculations regarding something travelling at Mach six going straight up (ie not realistic) and losing power at 22km would still mean it would go pretty high. It will be interesting to see if developments end up in the meso/thermosphere range with ballistic type trajectories. Below LEO sats, but above anything aircraft based.
Acoustics?
Yes, there are applications but I am curious as to why you would think that? The candidate orbits for hypersonic aircraft are low energy orbits. e.g. A Molniya orbit, used by earlier Soviet era spy satellites, is a low energy orbit.
cheers
w
I've been casually reading a few papers in this field, aeroacoustics is a recurring theme. I assume this may have been what GF was alluding too. I'm a physics guy, so I see waves everywhere anyway.
I would assume that they wouldn't quite achieve a Molniya orbit (at least initially), but something Molniya like, but theres not a whole lot of public information on the details to fill in the gaps, so I am now just playing around with some numbers to see what seems feasible. Its all very interesting, I will be watching to see where these technologies go.
Airborne acoustic anomalies are more easily controlled through changing the configuration of the source (the aircraft) itself. e.g. A hypersonic biplane reduces the acoustic signature dramatically over a mono-plane configuration because it creates wave cancellation and disruptor effects. You also get interesting compressive lift qualities from a biplane. There is plenty of open source information on supersonic biplanes.
The Return of the Supersonic Biplane - Popular Mechanics
cheers
w
Thanks for the info, I've got some more reading to do..