31 replies to this topic

[Stridercal]

Nobody admits they were wrong on the internet, so i just can't believe such a thing would happen. It's almost like you are decent person, acting reasonably.

... wow, suddenly i look and feel like such a ****.

[Ced Riggs]

Stridercal, on 29 June 2017 - 12:56 PM, said:

... wow, suddenly i look and feel like such a ****.

In my younger years, I commited so many internet debate sins, I deserve any and all rough words tossed my way. Don't feel bad. You just blew my happy place bubble about magic space guns.

[ChapeL]

What just happened here?? That's not how the internet works! That's not how any of this works! What have you done?!?!

Ahem... so any actual thoughts on UAC20 as 1 slug guns with recoil inbetween shots ?

[pyrocomp]

Tunanya, on 29 June 2017 - 11:34 AM, said:

Do...Do none of you understand how Gauss works? By the laws that we understand today, a Gauss projectile would generate a lot less recoil than say an AC20 counterpart. As there are no gasses to expel, there is one less variable to account for. The length of coils required to produce the magnetic PULL, not push, would also help dissipate the pushback values. The majority of the forces would be exacted upon the coils themselves...and why would we not load them with recoil tracts?

Yes, there IS recoil, but the stuff we see in game is for gameplay balance, not reality.

Reference:

https://physics.stac...ve-any-kickback
https://en.wikipedia.org/wiki/Coilgun (yeah, yeah, it's Wikipedia).

Take a moment to read carefully. You somehow just skipped the sentences about GR recieving momentum almost equal to that of a projectile. In the very post you've quoted.

ChapeL, on 29 June 2017 - 01:11 PM, said:

What just happened here?? That's not how the internet works! That's not how any of this works! What have you done?!?!

Ahem... so any actual thoughts on UAC20 as 1 slug guns with recoil inbetween shots ?

See above in between the tech takes that it might be ok, but requires testing. Poll it.

[Stridercal]

What happened here? Ced proved that i'm a jerk, jaded and argumentative without good reason.

Also, for my part, i've always thought Battletech ACs (of nearly any flavor) were multi-shot bursts. That's how they've always been described in the fiction. Hell, even the background wallpaper on this page shows a Rifleman spewing a whole bunch of discarded shells at once.

But that being said, the point of a Battletech autocannon is to put a lot of damage onto a single target location with minimal heat, so a burst of shells doesn't jive with that, either.

At the end of the day, i'm actually pretty pleased with most of PGI's balancing decisions, but I don't see a way forward on this issue that will make everyone happy...

[Tunanya]

pyrocomp, on 29 June 2017 - 01:28 PM, said:

Take a moment to read carefully. You somehow just skipped the sentences about GR recieving momentum almost equal to that of a projectile. In the very post you've quoted.


See above in between the tech takes that it might be ok, but requires testing. Poll it.

I love this. The both of you (You and Stridercal) are super quick to ignore what I actually wrote and take it as an attack that must be countered. Slow down a minute, there's too much hyperventilating in both or your posts' content.

I'll restate as I said originally "a Gauss projectile would generate a lot less recoil". At no point did I attempt to even HINT that there was no recoil. This ISN'T a recoil-less rifle. You, pyrocomp, appear to be cherry picking in that source material as much as Stridercal. There is certainly a good bunch of research on the hypothetical, and the real rail guns the armed forces have created would have helped prove and/or disprove it. Sadly I imagine a good deal will be classified for decades to come.

We also need to differentiate between felt recoil and recoil impulse. Felt recoil attributes to the shake in cockpit, which is apart from the impulse or "real" recoil.

But that doesn't preclude the fact that it generates less.. meaning that the shake is purely for game balance. Which is where I believe my argument was going in the first place. You also interpret push and pull as laughable, yet you talk about direction of force, Stridercal. It will indeed impart force in a fairly same amount to the given action, yet the blow-back is dampened by the heading of the projectile.

Strider, that's an excellent example on a small scale coilgun. I really wish we could go to the actual specs and documentation, but it appears that material is all offline at the moment. Let's try and give it a comparison, right?

Let's say the projectile is similar in mass and shape to a 6.5 Creedmore round. I'm more familiar with those than say 30-06, so it'll provide a general example. Imagine the coilgun's weight and profile are matched to the rifle firing the 6.5 to provide a basis for equality of test conditions.

Using a standard hunting round as the equivalent, the projectile is 100 Grains using a standard load of 40 Grains RL15 powder. Firing from a securely mounted position generates ~ 2950 ft lbs. of energy from the rifle. Can't say as to the coilgun, that'd require some real deep digging. Go for it if you'd like. However, left unsupported like you've referenced in the video, that gun would fly back a good 5 feet at a minimum. Again, we're not talking about no recoil, just comparatively less.

I'm sorry that my post appeared to have gotten you so flustered, and then haughty when you were tilting at windmills. It merely bugged the sh*t out of me that PGI seems to go for balance and the community then goes way off tangent and argues over the merit of the commenters postings.

Here's some of the references if you want em:

https://load-data.no...a/65-creedmoor/
http://emptormaven.c...coil-and-range/
http://www.hornady.c.../6.5-Creedmoor/

Edited by Tunanya, 30 June 2017 - 10:08 AM.

[Mike Barnes]

As to the UAC/20 single slug, I think they tested that privately, and determined it was too powerful. Probably why we have the massive ammo shortage for UAC/20s and 10s right now. The cockpit shake of hgauss is a holdover from TT, and whether you like it or not, the game sticks pretty close to TT where it can, and does a lot of simulating where it cant. I'm not interested in UAC/20s doing cockpit shake, because to get the amount of shake we would need to accomplish what you want, it would be way too much. More than double what you get out of firing dual heavy gauss right now. Also I feel that the IS UACs, Gauss rifles, LBXs, and to an extent the PPCs are in a really good place balance wise right now, don't screw with it, fix the actually broken things.

[Dr Cara Carcass]

Tunanya, on 30 June 2017 - 09:37 AM, said:

I love this. The both of you (You and Stridercal) are super quick to ignore what I actually wrote and take it as an attack that must be countered. Slow down a minute, there's too much hyperventilating in both or your posts' content.

I'll restate as I said originally "a Gauss projectile would generate a lot less recoil". At no point did I attempt to even HINT that there was no recoil. This ISN'T a recoil-less rifle. You, pyrocomp, appear to be cherry picking in that source material as much as Stridercal. There is certainly a good bunch of research on the hypothetical, and the real rail guns the armed forces have created would have helped prove and/or disprove it. Sadly I imagine a good deal will be classified for decades to come.

We also need to differentiate between felt recoil and recoil impulse. Felt recoil attributes to the shake in cockpit, which is apart from the impulse or "real" recoil.

But that doesn't preclude the fact that it generates less.. meaning that the shake is purely for game balance. Which is where I believe my argument was going in the first place. You also interpret push and pull as laughable, yet you talk about direction of force, Stridercal. It will indeed impart force in a fairly same amount to the given action, yet the blow-back is dampened by the heading of the projectile.

Strider, that's an excellent example on a small scale coilgun. I really wish we could go to the actual specs and documentation, but it appears that material is all offline at the moment. Let's try and give it a comparison, right?

Let's say the projectile is similar in mass and shape to a 6.5 Creedmore round. I'm more familiar with those than say 30-06, so it'll provide a general example. Imagine the coilgun's weight and profile are matched to the rifle firing the 6.5 to provide a basis for equality of test conditions.

Using a standard hunting round as the equivalent, the projectile is 100 Grains using a standard load of 40 Grains RL15 powder. Firing from a securely mounted position generates ~ 2950 ft lbs. of energy from the rifle. Can't say as to the coilgun, that'd require some real deep digging. Go for it if you'd like. However, left unsupported like you've referenced in the video, that gun would fly back a good 5 feet at a minimum. Again, we're not talking about no recoil, just comparatively less.

I'm sorry that my post appeared to have gotten you so flustered, and then haughty when you were tilting at windmills. It merely bugged the sh*t out of me that PGI seems to go for balance and the community then goes way off tangent and argues over the merit of the commenters postings.

Here's some of the references if you want em:

https://load-data.no...a/65-creedmoor/
http://emptormaven.c...coil-and-range/
http://www.hornady.c.../6.5-Creedmoor/

If the recoil was applied to the mech who fired the gauss, you would kick the mech so hard....it would throw it on its back from the recoil of the gauss bullet. And before somebody says there is no recoil on a rail or gauss gun - you are wrong. Actio = Reactio! Frces come in pairs. If you push your car you can feel it pushing back on you because your heands start to hurt when you pushg really hard. it doesnt matter what is responsible for the exchange of forces. Magentic fields, electic fields or direct contact - all teh same.

Let met calculate the forces for you.....

Lets first think about conservation of momentum:

m1*v1=m2*v2 with m1=100000kg for the assault to make it a best case scenario for the mech fireing the gauss and lets assume the gauss bullet is m2=125kg in mass, therfore talking about the normal gauss rife.

we get v1=m2/m2*v2 =2.5m/s=9kph so it would instantly (in the time the gauss accelerates to 2000m/s) which is in the millisecond timescale which we will soon see. Now you try to accelerate 100 tonns to 9kph in that time to get a feeling for the forces at work.


Now lets assume the barrel of the gauss is 6m long - could be easily 1/3 of the atlas height when i look at the models in game.
So we know that within 6m the bullet has to reach 2000m/s and that acceleration times time has to be 2000m/s. or in formulas

1.) a*t=2000m/s
2.) 1/2a*t^2=6m

inserting 1 into 2 gives 1/2*(a*t)*t=1/2*2000m/s*t=6m <=> t=12m/2000m/s=0.006s=6milliseconds!!!!!
therefore we can calculate the acceleration a*t=2000m/s <=> a=2000m/s/0.006s=333.333m/(s^2)=33.978.93g
So the bullet is roughly accelerated with 34000g.

we also know that actio = reactio -> force on the bullet = force on the mech.

F=m*a=125kg*333333m/(s^2)=41666666N. Thats roughtly 41.5 million Newtons over 6ms. Lets hope the recoil doesnt simply rip the weapon out of the side torso. Its as if 4.15 million tons would press against the shoulder for 6 milliseconds.

Wanna see what the heavy gauss does?
it has 2 times the mass, but only half teh bullet speed - here we can already see that it should have half the damage since kinetic energy scales linearily in mass quadratic in speed - > Ekin=1/2*m*V^2
Ekin_gauss=1/2*125kg*2000m/s*2000m/s= 250MJ
Ekin_heavygauss=1/2*250kg*1000m/s*1000m/s=125MJ (4 shots per ton =250kg per bullet - sarna)

since the formulas for impulse and force are given above i will just type the results and we keep in mind that pgi says bullet speed is only 1000m/s:

Speed of the mech in backwards direction after fireing:
t=12ms
a=83.333m/(s^2)=8500g
F=m*a=250kg*83333M/(m/s^2)=20833250N =20.8MN Or roughly half the force experienced by the normal gauss.
conservation of momentum would kick the mech backagain with 9kph since mass has dobules but velocity has halved and both contribute linearily.


Light Gauss 2500m/s 62.5kg :

t=4.8ms
a=520833m/(s^2)
f=m*a=6.25kg*520833m/(s^2)=32552083N so more than the heavy gauss but less that the normal gauss. 3.2million kilos for 4.8ms.
mech willbe instantly moveing back with 5.625kph.

Now imagine fireing 2 of those....
Every mech would fall down if any of teh mechwarrior games would have real physics build in.

Take your ac 20 now - same formulas apply. however at 5 shots per ton in sarna the bullets are 200kg and the speed is 650m/s. Just assume for a moment that the rilfe is equally long. you will ahve a lot less recoil on the ac 20.

And holy **** lets have a medium with 50 tons fire a singe normal gauss - 18kph backwards after 6ms.

Edited by Cara Carcass, 30 June 2017 - 11:36 AM.

[Dr Cara Carcass]

pyrocomp, on 29 June 2017 - 09:04 AM, said:

A side note, all you wrote is more or less true in the intertial reference frames. In non-inertial reference frames the second Newton's Law of motion is not applicable. And, to be fair, realistically inertial reference frame cannot be found withing this universe. Only the reference frames that can be considered inertial for some period of time to some extent. But that's not to the point of proposed IS UAC20 to be single slug weapon with recticle shake. I'm for that and for lowering of the GH on AC20 (IS at least).

This is wrong on so many levels....

Non inertial frames of reference - aka acceletrated frames are not used because they would create forces out of nowhere since F=m*a.


Now imagine watching a car standing still while you yourself are standing still -> constant velocity -> acceleration a =0 -> F=0*m=0. No forces at play.

Now imagine someone pulls you back and accelerates you away from the car.

1.) cars frame of reference is inertial since it doesnt accelerate and sits still with the car..
For someone in the car it would look like forces are working on you since you are accelerating away. Everything is cool, the guy pulling on you accelerates you and not the car.

2.) Your frame of reference is accelerated since somebody is pulling you away.
From your point of view the car accelerates away and therefore forces have to act on it. That means if your frame of reference is used, th guy pulling on you accelerates teh car - not cool something is wrong. A magic force appeared that pushes the car away from you.

General relativity makes some admendments and allows for accelerated frames of reference, however that is not of use for us, sicne we are very very very far away from relativistic velocities.

Edited by Cara Carcass, 30 June 2017 - 12:49 PM.

[pyrocomp]

Cara Carcass, on 30 June 2017 - 12:45 PM, said:

This is wrong on so many levels....

Non inertial frames of reference - aka acceletrated frames are not used because they would create forces out of nowhere since F=m*a.


Now imagine watching a car standing still while you yourself are standing still -> constant velocity -> acceleration a =0 -> F=0*m=0. No forces at play.

Now imagine someone pulls you back and accelerates you away from the car.

1.) cars frame of reference is inertial since it doesnt accelerate and sits still with the car..
For someone in the car it would look like forces are working on you since you are accelerating away. Everything is cool, the guy pulling on you accelerates you and not the car.

2.) Your frame of reference is accelerated since somebody is pulling you away.
From your point of view the car accelerates away and therefore forces have to act on it. That means if your frame of reference is used, th guy pulling on you accelerates teh car - not cool something is wrong. A magic force appeared that pushes the car away from you.

General relativity makes some admendments and allows for accelerated frames of reference, however that is not of use for us, sicne we are very very very far away from relativistic velocities.

Would you try now to explain what you didn't understand in the first place so that you went all the way writing the same thing as I wrote but with more words? And, a hint, non-inertial reference frames are used, always when it comes to acurate and precise calculations. There is no fear of inertia forces and those can be accounted for, but they do not have a counterforce so to say or, in other words, thier actions do not invoke a counteraction. And that was specifically written to adress the following statement

Quote

there is an equal and opposite reaction

just to clarify a bit.

[LordNothing]

i like the recoil mechanic. its whats been missing from the bigger guns in the game.

Edited by LordNothing, 30 June 2017 - 04:40 PM.

[Dr Cara Carcass]

pyrocomp, on 30 June 2017 - 04:07 PM, said:

Would you try now to explain what you didn't understand in the first place so that you went all the way writing the same thing as I wrote but with more words? And, a hint, non-inertial reference frames are used, always when it comes to acurate and precise calculations. There is no fear of inertia forces and those can be accounted for, but they do not have a counterforce so to say or, in other words, thier actions do not invoke a counteraction. And that was specifically written to adress the following statement

just to clarify a bit.

You are mixing forces with fictitious forces. A force that is born out of an accelerating frame of reference is a fictitious force that has no balanceing force for some cases since there is no real force at work. Thats what bothered me. Thats why i explained what is going on to make the other guy understand it better, since you attacked him on a point that has no place in this discussion.

One could also make an example where those forces stemming from an accelerated frame of reference are balanced. As soon as they arent in free space. For example, a train going from north to south on our globe will wear out one side of the tracks more due to the corilis force. Here the coriolis force is met with an actual force. The track accelerates the train when it goes south to increse its radial velocity to keep up with the ground. Thats a real force comming from the rails since they have differentradial velocities along the way from north to south. That force is also met with an opposite real force, inertia of the train.

There is also no accelerated frame of reference where a real force is not met with an opposite force. His assertion when considering real forces is right in every frame of reference. Ther might just be additional terms in accelerated frame of reference. No matter what frame of reference you choose - if i push a ball away from me, there will be a set of opposing forces at work.