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Old 2008-10-23, 22:06   Link #1221
Ithekro
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Could it be that Macross fleets can construct new Macross-type ships, but they have to order certian parts from Earth (Eden or wherever they are building them these days)? This would mean the construction of the vessel would be closer to the "frontline" where it is needed, but would keep the special construction equipment and designs out of potential enemy hands
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Old 2008-10-23, 22:32   Link #1222
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You mean like the gunship?
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Old 2008-10-23, 22:41   Link #1223
Haesslich
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Quote:
Originally Posted by Ithekro View Post
Could it be that Macross fleets can construct new Macross-type ships, but they have to order certian parts from Earth (Eden or wherever they are building them these days)? This would mean the construction of the vessel would be closer to the "frontline" where it is needed, but would keep the special construction equipment and designs out of potential enemy hands
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Originally Posted by ReddyRedWolf View Post
You mean like the gunship?
That's about the only way I see it working - colonization fleets can build the ships... but then they have to buy the heavy-duty weapons or transformation gear from the UN Spacy, who supplies them. Unless they're building the ships FOR the UN Spacy who crews them while they support the ships materially. Otherwise you run the risk of the technology getting into the wrong hands. At least, if you control the manufacture of the gunships, then the UN Spacy would have the advantage against Anti UN Spacy forces who didn't have them, even if they had the materials and know-how to build warships.

Plus it's a pretty good reason to justify why the gunships are seperate from the rest of the carrier for both of the Macross ship classes outside of the original Macross-class.
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Old 2008-10-23, 23:29   Link #1224
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Quote:
Originally Posted by Ithekro View Post
Could it be that Macross fleets can construct new Macross-type ships, but they have to order certian parts from Earth (Eden or wherever they are building them these days)? This would mean the construction of the vessel would be closer to the "frontline" where it is needed, but would keep the special construction equipment and designs out of potential enemy hands
If so I'm sure there would be a hell lot of bureaucracy involved. After all, we never saw a fleet with two super carrier class units. I'm sure they are permitted to repair or even construct one in the event the original was destroyed.
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Old 2008-10-24, 09:44   Link #1225
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Helmet Mounted Display used in the F-35 and some other 4th-generation fighters. A real-life version of the VF-27's virtual cockpit and the tracking system in the VF-25's helmet.

http://gizmodo.com/gadgets/combat-he...ies-260482.php
http://www.vsi-hmcs.com/pages_hmcs/03a_f35day.html
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Old 2008-10-24, 17:32   Link #1226
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Originally Posted by mechabao View Post
Helmet Mounted Display used in the F-35 and some other 4th-generation fighters. A real-life version of the VF-27's virtual cockpit and the tracking system in the VF-25's helmet.

http://gizmodo.com/gadgets/combat-he...ies-260482.php
http://www.vsi-hmcs.com/pages_hmcs/03a_f35day.html
Indeed - they've been working on those for over ten years now... and the virtual cockpits in Macross date back at least to Macross Plus with both the YF-19 and YF-21 having them, with the HMD-style displays as well, from what I recall seeing on the front of Isamu's faceplate.
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Old 2008-10-24, 20:29   Link #1227
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And you would definately not want to fire them unbraced in the atmosphere or while flying either in space or in the atmosphere. Especially in space where losing thrust is bad.
Firing them with legs in an atmosphere (I'm assuming that's what you meant, since I never claimed they should be fired while the thing is flying in an atmosphere) is bad since it will knock the mech on its ass. It's just not practical to put high recoil weapons on a machine with legs.

Saying "losing thrust in space is bad" shows you don't really understand how combat in space works. There are no brakes in space, there is almost no friction in space. Depending on the combat tactics, slowing down is completely logical, and firing your weapon while doing so, allows for different kinds of tactics. In addition, firing your weapon can also make you gain thrust, or change your velocity (speed and direction). All of these factors are important in a space setting.

Now, bracing yourself against a big ship so you can fire your railgun makes about as much sense as having walking 16 inch guns on a battleship. What's the point? There is no point, that's why they are turrets, not separate vehicles.
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Old 2008-10-24, 21:37   Link #1228
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Quote:
Originally Posted by Daigo View Post
Firing them with legs in an atmosphere (I'm assuming that's what you meant, since I never claimed they should be fired while the thing is flying in an atmosphere) is bad since it will knock the mech on its ass. It's just not practical to put high recoil weapons on a machine with legs.
Which is why there's a brace that drops down from the back of the Monster, but I believe this has been pointed out to you several times and you just keep ignoring it. I mean we even see the VB-6 brace itself in the show. So the VB-6 will not be knocked on is ass, because it's ass, if you will, drops down to brace the guns.

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Saying "losing thrust in space is bad" shows you don't really understand how combat in space works. There are no brakes in space, there is almost no friction in space. Depending on the combat tactics, slowing down is completely logical, and firing your weapon while doing so, allows for different kinds of tactics. In addition, firing your weapon can also make you gain thrust, or change your velocity (speed and direction). All of these factors are important in a space setting.
I apologize, I've been using thrust when I mean velocity. Guess I'm slipping in my old age here. Still, this is Macross, where Jackie Fischer rules and Speed is Armor. Typically, it's your *only* armor, outside of pin point barriers. If you're in shuttle mode, you're using it to get from point A to point B and losing forward velocity by firing your guns is probably less helpful than it sounds. Leave the shooting fast movers to the fast movers on your side, who should be escorting you anyways.


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Now, bracing yourself against a big ship so you can fire your railgun makes about as much sense as having walking 16 inch guns on a battleship. What's the point? There is no point, that's why they are turrets, not separate vehicles.
Well, you could ask Battle Galaxy and those Vajra in Episode 7 how much sense it
makes. Main point though, is that it makes sense in the Macross universe because they operate VB-6s. And for an organization that started as convoy escorts, that being SMS, a giant, mobile gun turret does make sense since they're probably escorting transports with little to no weapons.

Point is, someone thought it was a good idea in the Macross universe, and it has remained in use, if limited. This does make sense, since you don't need a VB-6 all the time. Sometimes though, you probably need a massive arty piece that can keep up with your main forces, which is exactly what the VB-6 is. It's never going to get a lot of screen time though, because like the VA-3 and the VF/VA-14 it's not a sexy fast mover.
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Old 2008-10-24, 22:25   Link #1229
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I want to point out something: the firing impulse of one of those railcannons, as Haess calculated, is about 968700 kN of recoil. Per gun. Which means that you're looking at total firing impulse of 3.9 MILLION kN.

The VF-25's engines, in contast, produce 1620 kN thrust per engine, for a total of 3240 kN thrust. And these are the most powerful Variable Fighter engines to date.

Now the Koenig Monster can go Mach 1.7 at 10k meters, so it should be possible to calculate from there how much thrust it has, but from the above it's obvious that it frankly does not have enough thrust to counteract the recoil of the guns firing.

"That's what recoil absorbtion systems are for."

And those work when it's braced against something. That's how ALL recoil absorption systems work. Recoil can only be absorbed if there's something that the gun is braced against.

"Well what about when it braces itself against the ships then? Why aren't the ships going off-course?"

More mass means that the force of the recoil is spread over a larger area, and ships have fucklarge thrust to move them anyway.
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Old 2008-10-24, 23:39   Link #1230
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Which is why there's a brace that drops down from the back of the Monster, but I believe this has been pointed out to you several times and you just keep ignoring it. I mean we even see the VB-6 brace itself in the show. So the VB-6 will not be knocked on is ass, because it's ass, if you will, drops down to brace the guns.
No, I remember it. I just don't buy it. The fact is, just because they draw it as such, doesn't mean that's what will actually happen in real life. In gundam seed, you have the freedom gundam that flies around with those retardo wings on its back, but that doesn't mean if you actually built one, it would be able to fly like that, let alone fly at all.

But even if I suspend my disbelief and accept that it can take the recoil, that still doesn't answer why it uses legs instead of treads with struts/braces. What advantage are you getting with those stumpy legs? Don't say greater all terrain movement, because that's bull. It could barely walk. Presumably the legs are there so it can move around a little after it lands, but why not just use treads for that? Where's the advantage of using legs?

Quote:
I apologize, I've been using thrust when I mean velocity. Guess I'm slipping in my old age here. Still, this is Macross, where Jackie Fischer rules and Speed is Armor. Typically, it's your *only* armor, outside of pin point barriers. If you're in shuttle mode, you're using it to get from point A to point B and losing forward velocity by firing your guns is probably less helpful than it sounds. Leave the shooting fast movers to the fast movers on your side, who should be escorting you anyways.
Ok, I've been trying to explain space tactics and the importance of changing velocity in space, but for the sake of argument, lets ignore that for a moment.

Think carefully about what you are actually saying. You are saying this machine depends on a much larger ship to actually fire. It depends on this larger ship to fire because the ship is much more massive, and therefore won't be as affected by the recoil of the guns. So basically the Monster has to follow this big ship around like a gnat, and if there are no big ships available then the Monster is screwed because it can't fire. And this is a good thing... how? Why doesn't that big ship just use a turret then? It would be even better at bracing for recoil, have more ammo, more energy which means greater muzzle velocity, and you could make it much bigger too. The whole concept of even having a Monster becomes a nonsequitor because all it is, is just a big, fat, vulnerable, floating turret that needs to latch on to a big ship like a parasite in order to even fire.

Quote:
Well, you could ask Battle Galaxy and those Vajra in Episode 7 how much sense it
makes. Main point though, is that it makes sense in the Macross universe because they operate VB-6s. And for an organization that started as convoy escorts, that being SMS, a giant, mobile gun turret does make sense since they're probably escorting transports with little to no weapons.
Then escort those transports with big warships ships then (which in Macross, they are). The Monster, as you envision it, is a non-sequitor, because it relies on big ships in order to even fire. It's just a turret.

Quote:
Sometimes though, you probably need a massive arty piece that can keep up with your main forces, which is exactly what the VB-6 is.
Again, just use the turrets on bigger ships for "arty" as you put it. Which btw, doesn't make sense since the ranges for space weapons like lasers or particle beams are in hundreds of thousands of miles where ironically, railguns are utterly inaccurate. Artillery is mostly a terrestrial concept, it doesn't have much relevance in space combat where everything is being fought at stupendous distances already.
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Old 2008-10-25, 00:36   Link #1231
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One thing, although I'll have to check further, the recoil of a rail gun is not like conventional chemical charged weapon where it is the equal going the opposite direction.
Remember the force that propels the slugs are by Lorentz force which acts 90 degrees perpendicular to motion and that electromagnetism creates a feed-back loop.
From what I read one of the problem with this system is that the muzzle trys to tear itself apart, meaning that reaction is feeding back into electromagnatism.
I am not saying that it has no kinetic recoil whatsoever but I do not think it is full force in the opposite direction of that of the projectile.
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Old 2008-10-25, 01:14   Link #1232
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Originally Posted by Tri-ring View Post
One thing, although I'll have to check further, the recoil of a rail gun is not like conventional chemical charged weapon where it is the equal going the opposite direction.
Remember the force that propels the slugs are by Lorentz force which acts 90 degrees perpendicular to motion and that electromagnetism creates a feed-back loop.
From what I read one of the problem with this system is that the muzzle trys to tear itself apart, meaning that reaction is feeding back into electromagnatism.
I am not saying that it has no kinetic recoil whatsoever but I do not think it is full force in the opposite direction of that of the projectile.
It's debated - the rails WILL be pushed 'sideways' by the magnetic field, which means you have to mount the buggers securely. The papers I've been looking at say the recoil'll mostly manifest at the breech... and based on a ballistic force of 2 mN there's still about 100,000 N (100kN) of trunnion load applied to the hull for about 100ms with a 1000kg recoiling mass... which is pushing down from the cannon into the body of the VB-6. To put this in perspective, the M256 smoothbore 140mm cannon used by the M1A2 Abrams generates about 14,244 kN of force in total to launch an M829A3 sabot round... or about one-seventh of the force that is being experienced here as recoil.. and the trunnion load is much less on the M256 as a result, but it is enough to push a 70-ton tank back onto its rear tracks, leaving only 1/6th of its total area is in contact with the ground at that point. If I've got all four cannons going and the figures hold up, that'll leave 200kN going down into the frame of the VB-6. I wouldn't want to see what that'd do the airframe if I didn't have myself mounted on a larger mass.

Last edited by Haesslich; 2008-10-25 at 01:26.
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Old 2008-10-25, 01:32   Link #1233
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The YF-19 and YF-21 ultimately could both move faster than was safe for the pilots, but from what I could see the shape-changing wing and the vector-thrusting that was a legacy of the Queadlunn-Rau design the YF-21 was based on made a huge difference with regards to the manueverability of the YF-21. VF-19's faster, but the VF-22 dives and climbs harder, and seems to turn better even if it has less overall thrust, and so can (especially with the larger number of micromissiles we saw Guld use) box a target in to kill it faster.
Well, considering specs of VF-22 as well as YF-21 it's Rate-of-Climb is much lower then YF/VF-19. This properly shows how much power difference we have in both of those Fighters. Diving ability is also a part of engines output potential so I'm guessing YF/VF-19 still does better then 21/22. If the flexible wings are somewhat capable of negating the 1 ton mass increase of the General Galaxy Fighter then this is probably the place where it can catch up to the 19. Then again, I feel sorry for VF-19 because it lacks the canards it's prototype had.

Those canards give a plane added stability as well as maneuverability. You see, my problem with the 21/22 Fighter is that realistically wise it is not possible for it to catch up to 19 with it's specs. Both present similar technology but as long as the limiters stay present on 21/22 it is bound to perform worse then 19.

This 'worse' exact amount is not know and we certainly saw that there is little to no difference in the anime but I'd rather take that as a plot necessary aspect of the show.




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Originally Posted by Haesslich View Post
Not a core, but still it was used with the elites, and Gamlin along with Diamond Force ended up flying the buggers as the VF-19's and VF-22's were only starting to come into service at this point (2045, or about five years after the ATF competitions which resulted in the final decision. Not a bad pace compared to real-life procurement processes. And you'll note that the VF-11 Thunderbolt was still considered a mainline fighter, as the VF-171 is in the 'current' (2059) timeframe.
I think we both can agree on this statemnt. It's satisfactory enough.



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Gravity is an insignificant force in space combat unless you're close to a planet's gravity well, and the deforming wings were supposed to help it in-atmosphere. The rear-facing canard just above the cockpit would've reduced the VF-19's maximum speed in atmosphere somewhat (which may be reflected in the stats that show it having a significant drop in speed compared to space) as it did with the VF-11. The biggest advantage for the VF-22/YF-21 based on how it heavily borrowed elements from the Queadlunn-Rau and other Zentradi power armor was that it was MUCH more maneuverable in space, and could literally turn on a dime while packing a lot of missiles.

In atmosphere, it could do very well... but at the same time the VF-19 did have an edge due to the way its wings and canard were set up, from what I could tell, and Isamu pushed it to its very limits.
Yes, gravity has little to no effect when you're flying in the depths of space. Then again, you'll always feel the g.forces because of the mass of your plane and it's acceleration. But that's beside the point.

I really hope the space modification of VF-22 had something to do with it's abilities. Even in space you have to have increased thrust / vernier output to move better, especially that mass. The specs say nothing significant about thrust so maybe verniers? I really can't tell.


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Speed's important for catching up with a target - but maneuverability comes heavily into play, and the VF-22 system seems to excel with that due to its thrusters and everything else it stole from the Zentradi designs. Of course, considering who founded General Galaxy, 'stole' is probably the wrong term to use with them. Speed is really important in intercept and pursuit missions where you have to catch up with or just catch a target - it lets you pull into range faster to fight. With BARCAP and FORCAP roles, it's less important than being able to maneuver and just latch onto the enemy craft... which Bowman and later Max and Millia managed to do very well with these superior craft.
Well, the thing with speed is tricky. It really depends where your craft is able to produce the said speed. We can have an afterburner speed or supercriuse speed like the present F-22. VF-19 speed comes solely from it's engines huge output. If the plane has the whole range of that engine power at standby in pilot's throttle leaver then it can perform a new range of maneuvers. Thrust vectoring of 19 along with it's acceleration abilities give it an edge in turning, climbing maneuvering. The problem here is how much the flexible wings can compete with all of that.

Then again, if we assume that zentradi tech was able to provide it a great deal of really powerful verniers then I guess we can say that 21/22 is comparable to 19 if not better. It's only an assumption though




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As for the VF-25S, the stats we have so far to compare with the VF-25F don't show any real difference performance-wise between the two, although historically pilots with squadron leader mecha tended to have better performance and maintenance done on the vehicles. Whether this was due to it being the squadron leader's mecha, or the squadron leaders historically being the best pilots (thus being able to pull more out of the mecha) is the question. The main thing that amazed Alto was that the Super pack, which was designed for extra performance in space combat, was not giving him an automatic edge over Ozma with the 'heavy Armored pack' that added four beam guns (on the shoulders), all those extra micromissile launchers, a radar unit for them, and extra armor plating on what would become the torso and arms and legs of the mecha (also containing micromissiles).
I think we weren't shown the full set of stas for both of the fighters. As you said, history has shown us that the leader always has a better unit. I just wonder how much. Still, I'd always take VF-25F over the darker S version simply because of the color scheme



EDIT. Well, this is how I see the competition between 19 and 22. I can't add much more then that so I'll just make this my last statement.

Rep + for a nice discussion on Macross. The thread really needed that
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Old 2008-10-25, 01:53   Link #1234
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Yes, gravity has little to no effect when you're flying in the depths of space. Then again, you'll always feel the g.forces because of the mass of your plane and it's acceleration. But that's beside the point.

I really hope the space modification of VF-22 had something to do with it's abilities. Even in space you have to have increased thrust / vernier output to move better, especially that mass. The specs say nothing significant about thrust so maybe verniers? I really can't tell.

...


Well, the thing with speed is tricky. It really depends where your craft is able to produce the said speed. We can have an afterburner speed or supercriuse speed like the present F-22. VF-19 speed comes solely from it's engines huge output. If the plane has the whole range of that engine power at standby in pilot's throttle leaver then it can perform a new range of maneuvers. Thrust vectoring of 19 along with it's acceleration abilities give it an edge in turning, climbing maneuvering. The problem here is how much the flexible wings can compete with all of that.

Then again, if we assume that zentradi tech was able to provide it a great deal of really powerful verniers then I guess we can say that 21/22 is comparable to 19 if not better. It's only an assumption though
One quick note - the special equipment lists for the VF-22 that I've seen all list an improved 'inertia vector control' systems that were derived from the Queadlun-Rau's. That seems to be THE thing that give it the extra edge in the G's it pulls despite not having the same raw thrust or high rate of climb enjoyed by the VF-19, although the Fire Valkyrie's modifications seem to make it better than the 'standard' VF-19 as far as its G-limits even if it has the older FF-2450B engines that also power the VF-22. The Queadlunn Rau, and now the -Rea, seem to be able to pull turns and maneuver better than any VF in existence EXCEPT the cutting-edge VF-25 Messiah and VF-27 Lucifer, whose performance profiles apparently edge out even the best current Zentradi tech. The -27 seems to hold a similar edge over the VF-25 due to its ability to push past human limits... which is probably why it reminded me of the VF-22 from Plus, especially with the semi-rivalry that Brera and Alto developed. Except these two pulled a Max and Millia at the end, instead of having Brera re-enact Guld's fight with the X-9...
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Old 2008-10-25, 02:03   Link #1235
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One quick note - the special equipment lists for the VF-22 that I've seen all list an improved 'inertia vector control' systems that were derived from the Queadlun-Rau's. That seems to be THE thing that give it the extra edge in the G's it pulls despite not having the same raw thrust or high rate of climb enjoyed by the VF-19, although the Fire Valkyrie's modifications seem to make it better than the 'standard' VF-19 as far as its G-limits even if it has the older FF-2450B engines that also power the VF-22.
Ah, yes, I see it. I wonder if it's all of the Zentradi tech that was implemented into VF-22. The fearsome thechnology of 500.000 cycles.


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The Queadlunn Rau, and now the -Rea, seem to be able to pull turns and maneuver better than any VF in existence EXCEPT the cutting-edge VF-25 Messiah and VF-27 Lucifer, whose performance profiles apparently edge out even the best current Zentradi tech. The -27 seems to hold a similar edge over the VF-25 due to its ability to push past human limits... which is probably why it reminded me of the VF-22 from Plus, especially with the semi-rivalry that Brera and Alto developed. Except these two pulled a Max and Millia at the end...
About this issue. It has been stated that VF-25 has ISC (Inertia Store Converter) possibly being a g. force nullification device of some sorts. I wonder if it has anything to do with Macross gravity control mechanisms. This would be the most logical assumption as Naked VF-25F thrust is enough to kill any pilot let alone 27's. I'm guessing that Lucifer is a machine that is beyond the reach of ISC operation limits. After all, the device has to have it's size and power limitations.
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Old 2008-10-25, 02:49   Link #1236
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This whole Monster discussion got me wondering what kind of spin would happen if a Koenig fired off a railgun while floating in space. I haven't taken a physics class in over a decade so this was a nice stretch, though I'm sure I screwed up somewhere.

First of all, I'm not sure where the .003s Haesslich used in his calculations came from... I assumed that with a 41m barrel, to go from 0 to 5812m/s, plug into F = mv^2/(2d) gives me 206,000kN or about a fifth of Haesslich's number. The time it would take came out to be about 0.014s (using t=2d/v). So definitely same ballpark, though not as nice a number as 1 000 000kN.

Then approximating the the Monster as a 25m diameter 100ton sphere and assuming it was fixed in space at it's center of mass (which is impossible of course) I got about 54rpm from firing one gun. Pretty nasty, even if reality would be some fraction of that.
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Old 2008-10-25, 03:30   Link #1237
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Originally Posted by Vulcannis View Post
This whole Monster discussion got me wondering what kind of spin would happen if a Koenig fired off a railgun while floating in space. I haven't taken a physics class in over a decade so this was a nice stretch, though I'm sure I screwed up somewhere.

First of all, I'm not sure where the .003s Haesslich used in his calculations came from... I assumed that with a 41m barrel, to go from 0 to 5812m/s, plug into F = mv^2/(2d) gives me 206,000kN or about a fifth of Haesslich's number. The time it would take came out to be about 0.014s (using t=2d/v). So definitely same ballpark, though not as nice a number as 1 000 000kN.

Then approximating the the Monster as a 25m diameter 100ton sphere and assuming it was fixed in space at it's center of mass (which is impossible of course) I got about 54rpm from firing one gun. Pretty nasty, even if reality would be some fraction of that.
I pulled the speed figures from the US Navy's specifications for that naval railgun that Daigo was talking about - and then got the time based on the length of the barrel (20m) from estimates based on the specified size of the VB-6 and the length of the railguns compared to the main body... which appears to be about 20-ish meters, as the remaining 9 meters of the airframe's length. Basically the way the HWR-00's and VB-6's guns are set up (bore size and apparent length) look to be Kawamori stealing the design from a battleship turret (the 16"/50 Caliber Mark 7 guns). This means that t=0.007, and now I see where I fucked up the calculations.

Just to be sure, what was the mass you were punching in there? I was doing just a straight F=ma calculation, IIRC, but substituted v/t as I didn't have the acceleration at the time. If I'm keeping the mass of the railgun slug at 500kg, then punching that into the formula (F=mv^2/td) along with the distance of 20m (2d = 40m) gets me a yield of around 422,242 kN... which is just under half of what I had with the incorrect figure (I had the time set too low), but still a godawful huge force.

Put that back into your formulae, and you get ugly numbers. This isn't even considering the possibility of shock damage to the pilot and equipment inside that frame, since they're not ALL going to move at exactly the same velocity. Oh, and sheer stresses on the frame at the point where the gun joins the body... and if you've got axial twisting of the rails that you have to stop (which is going to happen in a railgun), then THAT KE has to go somewhere too - like into the barrel, and then into the rest of the mount that connects it to the Konig Monster.
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Old 2008-10-25, 04:29   Link #1238
Tri-ring
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From reading recoils on railguns, I do not think the bulk of the force will react in conventional momentum conversion.

http://www.df.lth.se/~snorkelf/Longi...ml#LorentzRail

Quote:
Railgun recoil
Railguns were of interest in the 80s SDI-program. Today, interest in electromagnetic launching has revived in NASA's plans for a new kind of a space-shuttle. A railgun consists of two parallel bars and a transverse rod, the sleigh, Figure 2.7A. When a current is passed through the circuit the sleigh is accelerated due to the Lorentz forces (the conduction electrons in the sleigh move in the magnetic field from the bars). As can be seen, Figure 2.7B, these forces are strongest in the corner regions, and directed at right angles to the conductor, i.e. they are transverse. The recoil forces were expected to be seated in the rear, section III in Figure 2.7B. But recoil forces were also observed in the rails, the arrows in Figure 2.7A, pushing the rails back and thus deforming them. Some experimenters observed plastic deformation of the rails [5]. Others reported severe friction losses, which could be generated by transient bucking of the rails.

If you look at figure 2.7b the force is evenly spread at in all 4 directions.
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Old 2008-10-25, 16:48   Link #1239
Haesslich
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Quote:
Originally Posted by Tri-ring View Post
From reading recoils on railguns, I do not think the bulk of the force will react in conventional momentum conversion.

http://www.df.lth.se/~snorkelf/Longi...ml#LorentzRail




If you look at figure 2.7b the force is evenly spread at in all 4 directions.
The force is spread through all directions... but at the same time, it should be noted that the electromagnetic fields of the railgun themselves carry momentum back into the breech as they can conduct it. My concern here is, even with the force 'spread' out that way, you have to restrain the rails as otherwise they have a tendency to push away from each other as well as to twist slightly due to the way the fields work.

Graneau's work which the page you linked to shows ("Application of Amper's Force Law to Railgun Accelerators", Journal of Applied Physics Vol 53, 1982, pp 6648-6654) argues that the rails will be the part of the railgun which manifest the most stress near the armature which hold the rails (from what I could see there), but later works (Robson and Sethian, "Railgun Recoil, Ampere Tension, and the Laws of Electrodynamics", American Journal of Physics, Vol 60, No 13, December 1992, pp. 1111-1117) have shown that the force of the recoil is communicated by the magnetic fields into the breach itself... and of course, we still have to worry about where that force is going - namely into the mounting of the cannon, as well as into the barrel itself.

To sum up, most of the force will be borne into the breech of the railgun, but there will be some forces working on the railgun's rails as well, as the rails are pushed on by the magnetic fields that propel the projectile and the magnitude of which will depend on the ratio of the width of the rails... which in turn will carry into the bracing structures that will keep the railgun's rails from pushing themselves out of line. Oh, and the barrel itself may fail due to the stresses put on it by repeated firings; one reason I kept the number of reloads on a VB-6 Konig Monster low (7 rounds per railgun, per the original HWR-00 combat load) is due to the fact that after each mission Canaria sorties on and uses her railgun in, they probably have to replace the rails and barrels, as the rails may develop stress fractures due to the amount of force applied to both rail and barrel, as well as other issues that may come up (the amount of power being used by the railgun is also converted to heat, which the liquid cooling of the railgun is supposed to handle... but whether that also manifests itself as 'arcs' inside the railgun - which would vaporize metal off the rails - is another question we have yet to get an answer for).

On a tangent, am I the only person somewhat agape at how this debate went from 'flying mecha with treads' to the physics of railguns and scholarly debates, with the odd incoherent interruption that seems to exist seperate from the rest of the thread?
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Old 2008-10-25, 18:56   Link #1240
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*shrugs* This happens all the time in Outer Cadia and Nanoha Magitech. Contrary to what Daigo thinks, I'm used to it.
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