52 replies to this topic

[ManDaisy]

I don't know if this was addressed anywhere. In my opinion an AC 20 would have to deal with more kick then an AC 2, HOWEVER, whether or not this is already accounted and reduced in the battlemech and targeting computer to make it negligible, I wouldn't know.

[SquareSphere]

Nothing has covered this yet, but I hoping that there is side meta effects for large bores and the gauss rifle

[Stone Profit]

Yes, definitely. Fired a heavy gauss? hella recoil! I know we cant have HGauss yet, but Im waiting for it, along with a Heavy PPC and some MRMS!

[Zerik]

Makes sense. Bigger cannon = rocks you, and your enemy even harder than you.

[ManDaisy]

I was also hoping for a higher standard deviation from your targeting point the longer you go full auto on an auto cannon. Initially when your targeting computer and weapons synced up with where you were aiming you would have a small area where your bullets could land. As you fire off you have more recoil and your computer cant compensate so you area of bullet spread increases. Naturally for larger bore weapons the max possible bullet spread area would be larger. Ac 2's on the other hand should have a relatively small max bullet spread area.

Edited by ManDaisy, 09 February 2012 - 08:21 AM.

[Chuckie]

Guass/rail guns would have less recoil due to smooth nature of the way they fire (I.E. NO propellant), than a AC. According to physics, every action has a equal and opposite reaction, either heat or force is generated in launch. In the case of an AC its in a shell and the propellant explodes, having a kick like a piston. The Gauss/Rail guns would be smoother like a subway train taking off, but thier rails generate a lot of heat. It also stands to reason the more force the more reaction, so bigger ACs have more recoil no doubt.

In the realm of Guass/Rail Gun tech.. it would depend on the design and if that opposite reaction is force or heat and would greatly depend on the weapon and its design..

As for LRM/MRM/SRM they can either have a lot of recoil.. or no recoil at all.. depends on location of the missle rack and if it can vent the exhaust of the rocket or not. I.E. In the case of a stinger missile the tube is open to the rear and a man can fire it.. all gases are vented to the rear and thus no recoil.

So MadCat (no recoil as missiles can vent to the rear), Centurion could have recoil issues since the missile launcher is centered in the torso (harder to vent the missile exhaust).

As for Lasers/PPC they should have absolutely zero recoil.. the opposite reaction to their use is in the heat they generate.

At least that would be my take on it..

[Philipe von Rohrs]

I agree with larger recoil for larger weapons.

I know lasers are recoilless, but what of PPCs? They fire some form of matter don't they?

Edit: It's the 31st century (in game) right? We have recoilless guns now...

And 'mechs have gyros to help stability.

But I admit it woukd "feel" more visceral firing off rounds with recoil shaking the mech :-)

Edited by Philipe von Rohrs, 09 February 2012 - 08:30 AM.

[ManDaisy]

Missiles... I think and this is factoring minimum range... they have a duel launch system. First a small propellant fires them out of their launcher then once they are out the missile launcher, the main missiles fuels starts to burn off outside the mech propelling the missile forward. So missiles should have very little recoil. However if they performed like rockets on the other hand then recoil may be higher.

[Nick Makiaveli]

ManDaisy, on 09 February 2012 - 07:41 AM, said:

I don't know if this was addressed anywhere. In my opinion an AC 20 would have to deal with more kick then an AC 2, HOWEVER, whether or not this is already accounted and reduced in the battlemech and targeting computer to make it negligible, I wouldn't know.

Unless the AC/20 is just a AC/2 that shoots 10 times as many shots or is a collection of 5 AC/2s firing twice as many shots.

Point being, higher rating doesn't always means a bigger caliber. That was where the different manufacturers came in. Some made larger calibers, others just had more (or more effective) propellant charges etc etc.

[Jungle Plague]

Well, I think that the higher recoil for the bigger guns is a great idea. One thing that I think should be taken into consideration... The US Navy is currently developing rail gun technology. The guns, which they hope to put on ships in the near future, are absolutely monstrous. They launch a hunk of metal at, give or take, a zillion miles an hour. Even though the projectile is accelerated by magnets, and it gives a smoother accerlation curve, the projectile is nonetheless shot out of the barrel of the gun with a very high velocity. The impulse of the recoil may not be as high as that of a traditional chemical propellant, there is still a lot of recoil energy. (Though as fast as the projectile leaves the barrel I am sure that the impulse is fairly high) I think that, should gauss rifles be implemented (and lets face it we know they will) they should be a very high risk/high reward weapon. Railgun projectiles have such tremendous kinetic energy, I feel as if they have been shortchanged in past mechwarrior titles. Perhaps, they should have the instant travel time, as they did in mechwarrior 4, but they should have a charging time, similar to the Bombast Laser from the same title. Once the gun charges, it fires automatically. Essentially, the gauss rifle would have a 2 or 3 second delay from the pull of the trigger: making hitting a target a more difficult endeavor... but, if the projectile connects on target, it really does horrendous damage.

[Kartr]

The missile systems most likely have a two stage launch system. First a charge of compressed air throws the missile out of the tube and into flight, once the missile is far enough away from the 'Mech the main propellant charge kicks in and goes through its rapid burn. Once the propellant is burnt the missile finishes its arc without power, relying on its momentum.

Larger bore guns should have higher recoils as that is the easiest explanation for their extremely short ranges. The rounds themselves no doubt travel just as far as modern rounds (well over 3km), but the fact you're firing a burst means your grouping is going to loosen up very quickly. Its like firing an M16, when you fire it single shot 500m is your max effective range, when you fire it on Three ShotBurst your max effective range is closer to 100m or less.

@Makiaveli: The manufactures make the same caliber weapon that can use the same exact ammunition. That's why when you're on the battlefield you can salvage weapons and ammunition and expect them to work when you load them on your 'Mech. Standardization is extremely important on the modern battlefield as it eases the logistics situation. This would be even more true in wars that jump from planet to planet. Also the Master Rules Revised states that AC's are cannons ranging from 30mm to 120mm that fire multiple rounds in succession (not the exact wording as I don't have it sitting in front of me).

Besides even if it was multiple AC/2's that fire 10 times as many rounds, or 5 AC/2s firing in concert you would still have much more recoil than a single AC/2 firing its normal burst. In the first situation the recoil adds up leaving your weapon tracking further and further off target, just like when a Machine Gun is fired the succession of recoils forces the barrel upwards. In the second scenario you'd have significantly more recoil as 5 AC/2s fired off simultaneously.

Not going to comment on rail guns or PPCs as I do not have enough real world experience or knowledge to form an informed hypothisis.

[Tannhauser Gate]

+1

This is part of a whole level of immersive detail I’d like to see In MWO. I would be disappointed to see underwhelming weapon discharge effects. The majority of mech weapons range in size from heavy vehicle-mounted weapons to major field pieces that would have recoil, incredible noise, pressure waves and rippling heat as well as shell casings (if applicable), the hiss of cooling systems as they engage, and the reloading sounds all layered together in less than a few seconds. Awesome.

Also the environment would be affected by a weapon discharging nearby. Weve all seen WWII footage or Iraq video of artillery and tank cannons firing in the confines of a city street. The walls are hit by that pressure wave and plumes of dust rise, broken glass falls, and rubble bounces.

Id like to see that.

Edited by LakeDaemon, 09 February 2012 - 08:55 AM.

[Nik Van Rhijn]

From the fluff it seems that some of the weight of AC's is down to recoil absorbing systems and the computer/gyro's taking out the rest. Otherwise an arm mouted AC20 or Gauss Rifle (assuming it has recoil) would tear the arm off.

[Nasty McBadman]

The mass of the mech firing the weapon should also be used in determining recoil effects for ballistic weapons.

[ManDaisy]

Now there is something overlooked... bigger mech, better gyro, more force needed to shake the arms or torso.

Edited by ManDaisy, 09 February 2012 - 09:05 AM.

[Tannhauser Gate]

Regarding gauss weapons, in rl they do have recoil. Magnetic coils that accelerate a projectile would still be subject to newtonian physics even if theres no chemical propellant. There is an opposite reaction pushing against the mass of the weapon away from the projectile mass. There would be recoil effect especially if the weapon is suspended on a mech's arm structure as opposed to a concrete base the ground.

But, since this is fiction we can account for all kinds of advanced recoil compensation and dampening effects. Im sure the effects of recoil, propellants, mass, and newtonian physics have been well explained in BT terms.

Edited by LakeDaemon, 09 February 2012 - 09:19 AM.

[Aegis Kleais]

ManDaisy, on 09 February 2012 - 07:41 AM, said:

I don't know if this was addressed anywhere. In my opinion an AC 20 would have to deal with more kick then an AC 2, HOWEVER, whether or not this is already accounted and reduced in the battlemech and targeting computer to make it negligible, I wouldn't know.

Well, I could see that similar ignition method ballistics would have a feasibly higher recoil, like when comparing an AC/2 up to an AC/20. But when you get into other ballistics like Machine Guns and Gauss, whose to say that the method by which it imparts movement to the projectile (despite its slug characteristics or damage potential) would or would not be able to be of significantly lower recoil?

Helps to ensure a nice pro/con system so that not just every ballistic has the problem of recoil. Variety!

[Felix Dante]

I say recoil should be balanced with any weapon's size and type.

[Chuckie]

LakeDaemon, on 09 February 2012 - 09:18 AM, said:

Regarding gauss weapons, in rl they do have recoil. Magnetic coils that accelerate a projectile would still be subject to newtonian physics even if theres no chemical propellant. There is an opposite reaction pushing against the mass of the weapon away from the projectile mass. There would be recoil effect especially if the weapon is suspended on a mech's arm structure as opposed to a concrete base the ground.

True, I am just thinking it would be less than a comparable AC.. you would trade heat generation for smoother or less recoil.

Because unlike a propellant base weapon, its has more energy given to the projectile the further down the rail it goes, as opposed to having all the energy applied to it at the moment of ignition. So it should have a smoother launch and thus easier control and less recoil.

Again as you pointed out it is SciFi and not RL

[Strum Wealh]

Lasers fire photons, which have no rest mass.
Photons in motion, however, do have momentum represented as p = h/λ.
The "h" represents the Planck Constant, equal to 6.626x10^(-34) Joule-seconds (J*s).
The "λ" represents the wavelength of the beam (3.80x10^(-7) to 7.40x10^(-7) meters for visible light).
Recoil for a laser would be so small (values on the order of 10^(-27)) as to be negligible.
(Moreover, the beam, however, would exert some radiation pressure on the target. However, the effect of such radiation pressure on a multi-ton machine in a planetary gravity well would be negligible, so lasers would also have negligible/no "knock".)

PPCs fire heavier particles that do have rest mass (protons, neutrons, alpha particles, and so on) at velocities high enough to warrant describing in terms of fractions of c (the speed of light, ~3x10^8 meters per second), and so they would have recoil proportional to the product of the projectile's mass and said projectile's velocity (that is, recoil = mass * velocity).
Additionally, PPCs (unlike lasers) would produce "knock" as a result of momentum transfer to the target by the particles.

Flamers would likewise have some recoil proportional to the product of the mass (superheated gas) being ejected and the velocity of said mass (that is, recoil = mass * velocity).
However, with mass and velocity being rather low, I would think that the recoil (and knock) produced by a flamer would be so small as to be negligible.

ACs and MGs would also have recoil proportional to the product of the projectile's mass and said projectile's velocity (that is, recoil = mass * velocity).
It is possible, though, that they may include a recoilless operation (likely blow-forward or blow-back designs) in some models.



Gauss Rifles, being coilguns (NOT RAILGUNS!) or essentially very large and very powerful electromechanical solenoids, also have recoil (as a result of forces acting exerted by the magnetic fields and the projectile/armature on one another during firing) proportional to the product of the projectile's mass and said projectile's velocity (that is, recoil = mass * velocity).




For missiles, one would assume that the missile launchers have ducting and venting necessary to allow excess gas to escape, and so would avoid the issue of (significant) recoil by functioning identically to recoilless guns.





Your thoughts?

Edited by Strum Wealh, 09 February 2012 - 11:53 AM.