950 replies to this topic

[Alex Morgaine]

Tamara Xiang, on 06 August 2012 - 12:10 AM, said:

Maybe next time i get my Lostech Toaster, where i can warm up to 4 slices of Bread AT ONE TIME!!!

I got one of those, but still use my IS T2-O 2 slice toaster, cause it has a lil oven built in :3

[Theodor Kling]

Melcyna, on 11 August 2012 - 09:59 PM, said:

And naturally we also come into a real snag there in the recoil department when considering the fact that a 50ton battlemech firing an AC-20 have IDENTICAL gun performance as an Atlas weighing double of it firing the same gun, with the same weight and space... which of course would make no sense if you think about it from physical point of view (but it does naturally makes sense in gameplay point of view which is the main concern for the dev).

Now that you mention it... I never though of it, but good old Newton strikes again here.
As to the weight of the weapon: I think it´s not only recoil compensation. But also the loading mechnism. You need a fully automated mechanism that is capable of moving whole packs of ammo from whereever that is stored to the weapon.
Which leads to another realism problem: Most AC20s tend to be toso mounted.. no trouble there. But others are often arm mounted. While I can imagine a Rfileman or Jägermech to feed that ammo to the arms , basicly just gun barrels on a shoulder joint, I wonder how this is going to work in a Centurion, or even worse, most clan omni mechs. Those cute little arms of a Mad Cat don´t look to me as if they could hide an ammo feed from the torso to the weapon pods in the arms.

[Chaon]

People are a little confused over the range limitations of weapons in BT.

It is not that the weapon can't fire over their maximum range it is that they can't fire accurately over that maximum distance. You can still fire that MG at a target out 500m but your change of actually hitting something even as large as a mech and doing significant damage is nil.

Since mechs are almost constantly moving, firing mechs are going to have a lot of difficulty calculating firing solutions that deal with movement of the firing mech, movement of the target, any problems with the targetting mechanism of the weapon, any terrain between weapon and target, etc.

And a mech is limited in how big their computers can be and still deal with all the various requirments of moving, firing, detecting targets/companions/terrain, dealing with damage, running a fusion reactor, cooling, etc.

[Theodor Kling]

Chaon, on 12 August 2012 - 07:46 AM, said:

And a mech is limited in how big their computers can be and still deal with all the various requirments of moving, firing, detecting targets/companions/terrain, dealing with damage, running a fusion reactor, cooling, etc.

That is the problem.. BT assumes 80s Computers . It´s like saying Star Trek beaming is impossible due to the shear amount of data that needs to be stored. There is that comparisson that you would need a stack of harddrives form here to the moon to store it.. but that is from a time when a "huge" harddrive was coming near 1 GB, while having roughly the same physical size of todays 2TB ones. I mean there are enough other problems with beaming.. but the computer system is probably not it. Same should go for BT. Their computers are shown to generate holo-displays, with working speech recognition, controll said fusion reactors, generate threat analysis for display in the cockpit using multible sensor systems at once... but they can´t make a weapon shoot straight?!
You don´t realy need that complicated a targeting software to hit something as big as a mech on a few hundred meters. And something as slow as a mech, comapred to it´s size. Sure a mech can turn pretty fast, and bob and weave.. but it´s still a huge target. If the mechs are "too fast" to be properly targeted..have fun with aerospace fighters playing dive bomber on you.
And even if the computer can´t do it... a pilot might be able to do it. But the rules realy say: you can´t hit **** at a certain range. Even if you target a hex. A 30 m wide area that is not moving. Even if you don´t move! How inaquarate are thos weapons?
I can see some reasoning there for lasers. ( although those with energy densities large enough to be visible should reach a bit further). But with balistic weapons it is aboluteley nonsense.

[Melcyna]

Indeed..

Aside of the gun inaccuracy itself being quite ludicrous, the 'unable to hit or get targeting solution to fire' angle is very difficult to swallow as well when we use existing known history.

from as far back as WW2, we have mechanical gunnery director, essentially one of the first MECHANICAL analogue computer for combat use on an aircraft installed on B-29 superfortress, these are similar in principle as the computer installed on naval ships of the era (which incidentally are extremely light compared to BT computer).

They do pretty much exactly what BT primitive targeting computer do short of guiding missiles, and more in others... they even calculate lead automatically and compensate for inertia of the aircraft movement in effect on the rounds fired when providing the gunnery direction command to the turret.

And these analogue computer mind you are doing this against targets moving much faster (and suicidal in later part of the war as the japanese grew more desperate and started kamikaze attack against B-29 formation), and with much further range than BT combat, utilizing .50 cal rounds projectile flight time in the case of B-29 (except of the 20mm cannon on the tail).

Theodor Kling, on 12 August 2012 - 04:16 AM, said:

Which leads to another realism problem: Most AC20s tend to be toso mounted.. no trouble there. But others are often arm mounted. While I can imagine a Rfileman or Jägermech to feed that ammo to the arms , basicly just gun barrels on a shoulder joint, I wonder how this is going to work in a Centurion, or even worse, most clan omni mechs. Those cute little arms of a Mad Cat don´t look to me as if they could hide an ammo feed from the torso to the weapon pods in the arms.

One of my friend joked that the Timberwolf squeeze the ammo through the little arms with it's myomer bundle like an intestine instead of using proper bulky ammo feed through it, we had difficulty looking at Timberwolf with a straight face for a while after that.

Edited by Melcyna, 12 August 2012 - 01:48 PM.

[Bluetavius]

Okami Ryu, on 31 July 2012 - 08:59 PM, said:

rail guns are more costly and unwieldy than Gauss rifles

BT Gauss Rifle IS a rail gun, according to the Blood of Kerensky trilogy

Daniel Wraith, on 01 August 2012 - 06:35 AM, said:

Gaus slug is described as the size of a VW Bug being thrown an mach 6 I own a 72 vw bug i wish it could go mach 6

Blood of Kerensky says its watermelon sized, which with a rail gun, is as big as you would need it

[Melcyna]

Bluetavius, on 12 August 2012 - 02:00 PM, said:

BT Gauss Rifle IS a rail gun, according to the Blood of Kerensky trilogy

Which is actually a gross mistake when compared to the real world term...

a Gauss gun aside of utilizing similar basic EM principle, has a DRASTICALLY different propulsion mechanism to a Rail gun...

[Yojimbow]

Some really crazy things from BattleTech:

Myomer Bundles, how stupid is that right? I mean, like we could ever design something that contracts with electricity with enough force to move a mech.

oh wait: Nanotube Muscles

Fusion Reactors? Who would have thought you could pass magnetic fields through plasma created by a fusion reaction into a loop to generate electricity. How dumb.

Also, on the topic of Gauss vs Rail. Gauss rifles in BattleTech utilize a non-explosive projectile accelerated by magnetic field. Rail guns use the same principle. In essence, they are the same technology. DRASTICALLY different propulsion mechanism? Magnetic fields are not so drastically different from.... magnetic fields.

[Bluetavius]

Melcyna, on 12 August 2012 - 02:23 PM, said:

Which is actually a gross mistake when compared to the real world term...

a Gauss gun aside of utilizing similar basic EM principle, has a DRASTICALLY different propulsion mechanism to a Rail gun...

Yep

[Melcyna]

Yojimbow, on 12 August 2012 - 03:19 PM, said:

Also, on the topic of Gauss vs Rail. Gauss rifles in BattleTech utilize a non-explosive projectile accelerated by magnetic field. Rail guns use the same principle. In essence, they are the same technology. DRASTICALLY different propulsion mechanism? Magnetic fields are not so drastically different from.... magnetic fields.

Some basic physics behind Gauss gun and Rail gun and why the two are DRASTICALLY different.

Coil gun or Gauss gun works by series of electromagnets positioned in a series along the barrel initiated one after another just in front of the projectile, essentially dragging the projectile via a moving magnetic force done by energizing specific electromagnet rings calculated ahead of the projectile, then shutting it down as the projectile move to predetermined position, then energizing the next electromagnet rings set, and so on and so forth... until the projectile leaves the barrel (the last ring shut off before the projectile approaches the muzzle)

Railgun on the other hand consist of a pair of conductor connected to the main capacitor of the device (the conductor most logical form being a pair of rail, hence the name) and with the projectile forming the third part that connects the pair of the conductor/rail and allow current to pass through between them. The projectile then experience electromagnetic force represented by flemming's left hand rule that will push the projectile along the direction of the axis of the rail as long as potentials are applied to the conducting rails and current flow through them (essentially similar to a motor but on a linear path).

Unlike the Gauss gun, in the Railgun the projectile (or it's sabot or enclosure) forms the complete electrical circuit together with the rails that essentially produce the basic function of the device. And unlike the Gauss gun the Rail gun are not dependent on timing, whereas a Gauss gun must time each of it's electromagnet rings correctly to produce the most net force on the projectile, the Railgun in it's basic form simply energize the conducting rails until the projectile or it's sabot that forms the device leaves the muzzle, upon which the device circuit is severed since the projectile itself was part of it.

These incidentally are basic high school physics...

The two are so different that no one will mistake one for the other assuming they know at least the base principle in which they function.

To put an analogy of it, cannon shell and rocket propulsion are essentially based on the principle of gas expansion... however the two are drastically different in terms of how they actually utilize the principle and achieve the net force effect.

Edited by Melcyna, 12 August 2012 - 05:18 PM.

[Nebfer]

Theodor Kling, on 11 August 2012 - 09:53 PM, said:

AC calibres are only estimates, because as you said, exeptions exist due to different rounds per burst.

True but thoughs are the calibers that tend to show up for a given class.

Melcyna, on 11 August 2012 - 09:59 PM, said:

You are correct, i stand corrected with the KE figure, i missed the 0.5 modifier (that was embarrassing mistake right there) so the speed figure for the 600MJ i did actually applied for the 300MJ.
With regard to the speed though, that's still not that fast... at 2,191m/s or Mach 6.4 assuming of course that the 300MJ figure holds.
Current US ammunition for example is slightly slower since they have their own line of thought on how to best achieve the penetration (and they are less picky about using DU penetrator of course).
The german and most EU nations on the other hand that utilize tungsten heavily had to increase the muzzle velocity further to improve penetration performance, Rheinmetall D43A1 for example (which is pretty old shell back from 90s) is reaching speed of 1740m/s, and that was just using the shorter L/44 barrel... with L/55 barrel and further optimization on the propellant reaching Mach 6 is probably achievable for the next gen shell... though from there it's probably going to be extremely difficult to proceed any further without enlarging the bore.

From what I have seen we will not be reaching mach 6 any time soon with current technology's, their is a reason why a number of military's are looking into ETC, liquid and or Electromagnetic systems, as we are reaching the limits of current technology.

In any case we only have a basic idea on how fast a Gauss round is, we know two things on it's velocity, their commonly stated as hypersonic, the second is that their supposedly twice as fast as conventional weapons (or in some vases simply stated as having "incredible velocity's"). We also know that current B-tech auto cannon rounds have superior velocity's to current day weapons.

Quote

And if we want to think of the AC and Gauss rifles weight as coming from their recoil counter though, then we kinda hit a snag when we compare them to the ground vehicles... since logically the lower profile vehicles with their lower center of gravity would have superior recoil management performance.
So they either need less heavier recoil dampener or their gun performance would've been superior...
in particular the popular notion seems to be that the larger AC have shorter effective range because of the burst 'recoil' (evidently all that weight wasn't enough to fit dampener sufficient for it), but if such is the case then when mounted on the heavy tanks the AC should have superior performance.
And naturally we also come into a real snag there in the recoil department when considering the fact that a 50ton battlemech firing an AC-20 have IDENTICAL gun performance as an Atlas weighing double of it firing the same gun, with the same weight and space... which of course would make no sense if you think about it from physical point of view (but it does naturally makes sense in gameplay point of view which is the main concern for the dev).

That last sentence you wrote should of answered 90% of your questions... If it was not then then the game would be absurdly complex for most people to play and or balance properly... (yeah lets have at lest a dozen different configurations for the same weapon... as we now have to account for ones on mechs, dropships, buildings, tanks, blue water ships and towed guns for infantry use and not to mention different weight classes...)

Look your thinking way to hard about this, and if you look at almost every sci-fi out their it will catastrophically fail at some point with the kind of analyzing your doing...

Writers (as well as game creators) do not have PHDs in physics, nor majors in engineering or even medical degrees.... So their bound to have at lest some flaws. This dose not stop though who are willing to look at the series to see what kind of feats it's capable of doing, this is not an easy task at times (made harder at times due to the limited info available). However for the most part many series can have a basic understanding of what they can do.

Edit:
Most what if debates I have read and done generally do not go into this kind of nitpicking...

edit 2:

Ide thought I would mention this
One of the older explanation of B-techs ranges comes from the older B-tech mag (IIRC issue #3) it basically mentioned it was due in part to three things (with a battlemech bias) -this dates to around 1988ish
1: mechs are highly mobile, and difficult to hit at range
2: ECM is heavily used, making it difficult to detect and target units at range
3: the armor made it difficult to damage at longer ranges partly due to the effect of it's movement at range, making it able to disperse more of the damage (i.e. the more concentrated the damage the better).

Recoil while not specifically mentioned dose help in the regards as it would at range reduce the ability for the weapon to concentrate damage.

It also mentions that technology even in 3025 days was in the range of 21st or 22nd century levels...

Also it has a set of rules that brings the weapons to a more realistic range level

Ballistics have a max range of 7.5x long range (I.e. an AC-20 would have a range of just over 2km)
Missiles have a range of 5x long (LRMs would have a range of 3.15km -not to bad for a 8.33kg missile)
Energy is line of sight.
MGs have a 15x modifier but can not harm armored targets at that range

Edited by Nebfer, 12 August 2012 - 06:02 PM.

[Sidney]

Nebfer, on 12 August 2012 - 05:29 PM, said:

Writers (as well as game creators) do not have PHDs in physics, nor majors in engineering or even medical degrees.... So their bound to have at lest some flaws. This dose not stop though who are willing to look at the series to see what kind of feats it's capable of doing, this is not an easy task at times (made harder at times due to the limited info available). However for the most part many series can have a basic understanding of what they can do.

Perkins- is that you?

In any case, I would point to "Cray" who has been a writer for Battletech for years now. He's a materials engineer and seems to be doing an excellent job in shoehorning a 1980's game setting into something that at least seems somewhat reasonable to reality.

[Melcyna]

Indeed... which is where the FUN! is

you expose them to extensive thought process gauntlet using known principles (tech can change, but the basic physics principle wouldn't unless stated otherwise).

and you can find interesting things... Cray for example arguably did an impressive work indeed the more i read about his work on attempting to put a coherent tech Lore for it, it's impressive enough that essentially one can see where it's his work, and where it's likely someone else's... the tech manual makes for a very amusing read once i realized that he was working with external limitations as well.

[Sidney]

Melcyna, on 12 August 2012 - 09:02 PM, said:

and you can find interesting things... Cray for example arguably did an impressive work indeed the more i read about his work on attempting to put a coherent tech Lore for it, it's impressive enough that essentially one can see where it's his work, and where it's likely someone else's... the tech manual makes for a very amusing read once i realized that he was working with external limitations as well.

Indeed. There's a bit of 'tongue in cheek' humour to his work too, where he pokes fun at how the earlier explanation isn't correct (and has been pointed out by fans).

As for limitations, I remember he once took at look MechForce U.K (MFUK)- an official (although non-canon) 'fanzine' back in the FASA days. MFUK were the ones that originally came up with the Rotary Autocanon, although it had been Clan based, and not Inner Sphere.

It also came in all four flavours.

Their example design featuring it was a Clan vehicle that weighed 200 tons as I recall, and mounted *TWO* RAC20s.

Which is what Cray decided to look at.

From what I remember, he pointed out that this tank was capable of putting 2.4 Tons of ammo down range per turn.

At which point the recoil generated from Newton's Third Law dictated that the tank would actually be launched backwards several hexes. More hexes than the engine could drive it forward.

EDIT: The post must have been on the old CBT forums that are no longer available. The only thing I could dig up was a discussion about RACs on Sarna. Cray explains RACs- at which point someone asks about the Clan RACs.

Cray answers: "I try to forget about CRACs."

Edited by Sidney, 12 August 2012 - 09:25 PM.

[Yojimbow]

Melcyna,

I highly doubt you graduated with a degree in Engineering (I did). And I highly doubt you study the field of electromagnetic propulsion (I do). Please don't reference high school physics when you attempt to make an argument. In both scenarios, an electromagnetic field propels the projectile. This is a far cry from your analogy of gas expansion. The gauss rifle and the rail gun are both based on the relationship between current and voltage which is identical to the relationship between electrostatic and electromagnetic forces. The fact that one includes the projectile to complete a circuit or not is an elementary argument at best.

Given the two are different in this fact, I will grant you they are "different" but we are talking about a game that introduced us to this technology in 1980. By this time, very few people were aware of Hansler or Henry but they are both functionally identical. A better analogy would be the standard combustion engine vs a Wankel engine. Both operate on internal combustion, but convert energy differently.

As a side note, and one that has no benefit to this argument, is that the technology in BattleTech started my interest in theoretical physics. I'm not trying to start a full-scale argument, but the technicality you put forth demanded a retort.

[Melcyna]

I suppose i should've used a better analogy, that was a poor one i used indeed...

But since you have a degree in Engineering then you should fully realize the significant difference of railgun and coil gun/gauss gun base principle... and ESPECIALLY as an engineering graduate you should be fully aware that mistaking one for the other is inexcusable.

And the reason why i mention the part with it completing the circuit is because when you attempt to build a simple railgun, THIS will be one of the first obstacle you'll face when you start putting significant current through them. Wait, scratch that, it will be a problem on a railgun regardless of it's complexity, that has to be compensated for... and one of the most significant one too.

Most enthusiast new at this will lose a few of their early prototypes to it... a problem that the coil gun does not face.

Edited by Melcyna, 13 August 2012 - 12:43 AM.

[SakuranoSenshi]

I agree that the difference between railguns and coilguns is largely semantics. I know why they are different but I also know that they use exactly the same principles to generate their force, when you get down to it. Technically, both are a form of motor.

[PewPew]

Everyone does not go blind when a laser is fired.

[NocturnalBeast]

Houses invest in mechs rather than nukes.

Houses invest in mechs rather than nukes.

[SakuranoSenshi]

PewPew, on 13 August 2012 - 09:59 PM, said:

Everyone does not go blind when a laser is fired.

What makes you think they should?

The only real thing with the LASERs, or rather the most obvious thing with them, is that you can't actually see a LASER beam unless there is scatter (say from dust) or you're on the receiving end. However, to do damage with one you probably want non-visible frequencies anyway.

Edited by SakuranoSenshi, 13 August 2012 - 10:48 PM.