146 replies to this topic

[Johannes Falkner]

Ranger207, on 15 April 2012 - 03:36 PM, said:

Exactly correct. The force of the recoil has to overcome inertia first, so after that, recoil isn't that bad.
Where did you get those huge numbers?!?

Volthorne, on 15 April 2012 - 01:39 AM, said:

I want to know where you came up with those absurdly large numbers. Your final calculated acceleration puts the projectile at 367.35 mach/s^2 (which is, frankly, an oversight not even FASA could manage).

@Volthorne - m = meter... standard notation. You should note that I wrote v=1,000 m/s (~mach 3)... At sealevel and standard temperature and pressure mach 1 is 343 m/s.

The huge numbers come from the time term being squared.
from the first equation:
t = 1000 m/s divided by a
t^2 = (1000 m/s)^2 divided by a^2
t^2 = 1,000,000 m^2/s^2 over a^2
Then since the second equation is d=0.5*a*t^2 one of the a's in the divisor is multiplied out leaving
d=0.5 * 1,000,000 m^2/s^2 * 1/a
since d=4m, the second equation can be rearranged so that
a = 0.5*1,000,000 m^2/s^2 *1/4m = 125,000 m/s^2

Edited by Johannes Falkner, 15 April 2012 - 03:54 PM.

[Strum Wealh]

Johannes Falkner, on 15 April 2012 - 03:52 PM, said:

@Volthorne - m = meter... standard notation. You should note that I wrote v=1,000 m/s (~mach 3)... At sealevel and standard temperature and pressure mach 1 is 343 m/s.

The huge numbers come from the time term being squared.
from the first equation:
t = 1000 m/s divided by a
t^2 = (1000 m/s)^2 divided by a^2
t^2 = 1,000,000 m^2/s^2 over a^2
Then since the second equation is d=0.5*a*t^2 one of the a's in the divisor is multiplied out leaving
d=0.5 * 1,000,000 m^2/s^2 * 1/a
since d=4m, the second equation can be rearranged so that
a = 0.5*1,000,000 m^2/s^2 *1/4m = 125,000 m/s^2

One critique I have is that BattleMech-mounted Gauss Rifles are more often described as "hypersonic", which implies a muzzle velocity of at least Mach 5.0 (~1,710 m/s under standard day conditions), and likely not much more than Mach 10.0 (~3,415 m/s under standard day conditions).
Though, the Gauss Rifle on the Yellow Jacket VTOL is stated to have a muzzle velocity of Mach 2.2 (~749 m/s under standard day conditions), implying that it can be toned down if needed (as a 30-ton VTOL in flight might not be able to handle the greater recoil of a "full-power" shot, or be able to sustain a reasonable ROF on an ICE with "full-power" shots).

Also, there is a rather interesting paper describing the 45-stage (1 stage = 1 coil) coilgun mortar being developed by DARPA (the US Defense Advanced Research Projects Agency), titled "EM Mortar Technology for Indirect Fire" by B.N. Turman et al.
Of particular note is this section:

Quote

The coilgun barrel is a space-frame that aligns and axially compresses the individual coils over a thin-wall fiberglass boretube. This barrel frame is coupled into the gun mount that is the same size as used in the Future Combat System (FCS) NLOS-M vehicle. The mount contains the recoil system and is capable of elevating the gun for future field demonstrations of projectile range capability. Also located in the mount is the 94 GHz Doppler radar that senses the projectile during launch for controlled firing of the individual coils. The hardstand and baseframe are coupled to conserve the momentum of gun’s and catcher’s recoil.

And their target "launch velocity" (muzzle velocity) was on the order of only ~420 m/s (approximately Mach 1.23).

I would imagine that similar issues - and methods for resolving those issues - would apply to a weaponized direct-fire coilgun (e.g. Gauss Rifle)...

But, yeah... about those ACs...

[Johannes Falkner]

Strum Wealh, on 15 April 2012 - 05:14 PM, said:

But, yeah... about those ACs...

Yeah, I was trying to put the GR thing to bed so we could get back to arguing over bursts and whether they should be hyper accurate or not and how fast the shells should travel. It just got more involved than I expected with the poor algebra and reading skills in use.

to be clear:
Thread = ACs = Good
Post = Gauss Rifle = Bad

[Nik Van Rhijn]

The one thing that *I think most people are agreed on is that whatever mechanism is posited for AC's, damage should be done in one area. Now whether that is a burst of shots all impacting the same "hitbox" is another matter, it is the implementation in game that is the point.

If they do internal modelling of "criticals"/equipment then it may make more difference rather than just armour reduction. The LB 10X firing "shot" has 10 individual "pellets" to be accountes for. Any one of which can achieve a TAC, which is the only reason not to use a solid slug, and could be spread over a number of hitboxes, depending on the range and dispersion.
This does assume of course that we will have both types of ammo and that we will have TACs.

[Johannes Falkner]

I wonder if people would go for having an AC fire a burst with greater than listed damage on the assumption that you will miss with X% of the shells?

[RogueSpear]

My idea for the ACs would be to have the users choose what type of weapon they want, a single shot AC like in all the footage shown so far, or a burst weapon (Perhaps pay-for-change? Similar to premium ammo on WoT? Entirely new weapon?). We already have autocannons in today's militaries that work on this principle - short magazines for burst fire. If it's a purely aesthetic change, justify it by having the aiming software take into account the delay and the movement, moving the gun as it fires to land all shells on target. If it actually is a functional change, perhaps have the burst weapons do more damage overall to compensate for less single point damage, hold more ammunition, cause more dramatic rock (Half a second of constant juddering is more significant than a single large knock, weapon focussing wise) or similar. Any thoughts?

Note: I know some of the above suggestions conflict with TT, but as the tagline says, this is not your father's mechwarrior. The game has to be balanced in it's own right, rather than being broken because of religious adherence to turnbased rules, so please don't dismiss them out of hand for that reason!

Edited by RogueSpear, 16 April 2012 - 08:13 AM.

[Kartr]

Johannes Falkner, on 16 April 2012 - 07:54 AM, said:

I wonder if people would go for having an AC fire a burst with greater than listed damage on the assumption that you will miss with X% of the shells?

I could get behind this. The AC principle remains the same, but the weapon fires a couple extra shells so that you'll get the full rated damage in one location. You might get some extra points somewhere else because the duration of the burst was longer due to the extra rounds, but the rated damage gets slammed into one location.

RogueSpear, on 16 April 2012 - 08:12 AM, said:

My idea for the ACs would be to have the users choose what type of weapon they want, a single shot AC like in all the footage shown so far, or a burst weapon (Perhaps pay-for-change? Similar to premium ammo on WoT? Entirely new weapon?). We already have autocannons in today's militaries that work on this principle - short magazines for burst fire. If it's a purely aesthetic change, justify it by having the aiming software take into account the delay and the movement, moving the gun as it fires to land all shells on target. If it actually is a functional change, perhaps have the burst weapons do more damage overall to compensate for less single point damage, hold more ammunition, cause more dramatic rock (Half a second of constant juddering is more significant than a single large knock, weapon focussing wise) or similar. Any thoughts?

Note: I know some of the above suggestions conflict with TT, but as the tagline says, this is not your father's mechwarrior. The game has to be balanced in it's own right, rather than being broken because of religious adherence to turnbased rules, so please don't dismiss them out of hand for that reason!

Actually all the AC fire I've seen so far is bursts. At about 6s into the game play trailer the Atlas the camera is in fires a burst of what looks like 5 shells, at about 17s the Hunchback on the left fires what appears to be 5 or 6 shells in a single burst from its AC.

That kind of aiming software doesn't exist until the Clan targeting computer and then in 3068 the IS version of that. The normal targeting computer can only give you an aimpoint not adjust the aim of your weapons mid burst.