478 replies to this topic

[Nightbird]

I'm pretty sure pistols and rifles have gotten a lot lighter and also perform better than 80 years ago...

[0Jiggs0]

Nightbird, on 10 March 2018 - 02:53 PM, said:

I'm pretty sure pistols and rifles have gotten a lot lighter and also perform better than 80 years ago...

They are also firing slugs that weigh substantially less. WW2 rifle slugs weighed around 150-200 grains, where modern slugs are generally between 50-60 grains. Modern weapons weigh less because lighter weight ammo removed the need for them to weigh more. A better example would be the flywheel in an automobile engine. If the wheel weighs more, the engine has more work to do to turn the wheel, so its RPM will increase/decrease more slowly. Decrease the weight of the wheel and RPMs increase more rapidly, but also fall more rapidly as well. Make the flywheel too light, and the engine may begin to stall when the throttle isn't applied.

The availability of lighter weight materials does not override the engineering need for mechanisms to have a specific mass in order to function properly.

[Nightbird]

And if you hold the number of grains and projectile weight/size constant... no improvements in reliability, weight, fire rate?

[Grus]

size does not dictate mass or weight..

[Nightbird]

Grus, on 10 March 2018 - 04:34 PM, said:

size does not dictate mass or weight..

Nightbird, on 05 March 2018 - 08:07 PM, said:

So I got a question. I've been thinking though the density question, and here's what I got.

Say we start with a standard structure and standard armor Commando and Atlas.

(1) 10% of the weight goes to structure, and 20% (approx) goes to armor. The structure and armor should be the same density, given how it's all swappable (in case of structure as scrap). At this point, we've used up 30% of the total weight and at the same density for both mechs.

(2) The remaining 70% of the tonnage goes into the 53 free slots. We know the slots are the same size, since if they scaled with tonnage a 3 slot DHS on a Commando would take up less than 1 slot on an Atlas, which is not the case. It doesn't matter which slots you fill and which slots you leave empty, you have 17.5 tons versus 70 tons going into the same sized 53 slots.

We don't know what % of the total volume the structure and armor take up, but we do know that for 30% of the total tonnage, the density is the same, and for the other 70%, the Atlas is much more dense (4x more). Right? Or can there be other 'empty space' in a mech that is not part of the slot system?

Unless you meant the Atlas is stuffed with feathers and that's why it's so large, in which case... touché!

Edited by Nightbird, 10 March 2018 - 05:23 PM.

[occusoj]

0Jiggs0, on 10 March 2018 - 04:04 PM, said:

They are also firing slugs that weigh substantially less. WW2 rifle slugs weighed around 150-200 grains, where modern slugs are generally between 50-60 grains.

Thats only true for small calibers like the .223 or 5,45x39 that became popular - partly due to their smaller weight.
Theres still a good deal of heavier calibers like the .308 in use. Especially when it comes to machine guns or long range shooting.

0Jiggs0, on 10 March 2018 - 04:04 PM, said:

Modern weapons weigh less because lighter weight ammo removed the need for them to weigh more.

The ammunitions weight is irrellevant, its (mostly) the smaller bore diameter, smaller physical dimensions of ammunition and somewhat better materials.

0Jiggs0, on 10 March 2018 - 04:04 PM, said:

The availability of lighter weight materials does not override the engineering need for mechanisms to have a specific mass in order to function properly.

Which mechanisms in a gas operated self loading or even manual repeating rifle require a 'specific mass' to function properly?
Maybe weight is an aspect when it comes to barrel harmonics but the average soldiers service rifle or civilian firearm for sure isn't tuned to a point where it would even remotely matter.

Even most blowback designs could be adapted for a wide variety of component weights.

Nightbird, on 10 March 2018 - 02:53 PM, said:

I'm pretty sure pistols and rifles have gotten a lot lighter and also perform better than 80 years ago...

Not by a lot lighter when comparing roughly similiar rifles.
A Mosin Nagant 91/30 still weights roughly the same as a stock 700 Remington in .308.
Our militaries assault rifle, which uses a lot of plastic to become more lightweight, only is about a pound less than a Garand.

Nightbird, on 10 March 2018 - 04:26 PM, said:

And if you hold the number of grains and projectile weight/size constant... no improvements in reliability, weight, fire rate?

Weight only with some pistols.
Otherwise, not a lot since WW2.
Current small arms are still mostly based on 40/50s technology with barely any substantial changes/improvements. Even the often praised but never widely adopted concept of caseless ammo dates back to the fourties.
The seemingly modern Bullpup design goes back right to 1900 or so.

[Nightbird]

occusoj, on 10 March 2018 - 04:57 PM, said:

Not by a lot lighter when comparing roughly similiar rifles.
A Mosin Nagant 91/30 still weights roughly the same as a stock 700 Remington in .308.
Our militaries assault rifle, which uses a lot of plastic to become more lightweight, only is about a pound less than a Garand.


Weight only with some pistols.
Otherwise, not a lot since WW2.
Current small arms are still mostly based on 40/50s technology with barely any substantial changes/improvements. Even the often praised but never widely adopted concept of caseless ammo dates back to the fourties.
The seemingly modern Bullpup design goes back right to 1900 or so.

Lots of great info! Even if only a pound, that's what? A 15% improvement? 15% over 80 years, 60% over 1000 years... not impossible.

As far as handling the recoil, at least in fiction science, the mech has actuators and gyros on top of the weight of the weapon to handle it, whereas modern artillery must handle 100% of the recoil themselves right?

[occusoj]

Nightbird, on 10 March 2018 - 05:14 PM, said:

Even if only a pound, that's what? A 15% improvement?

Yes, about 15%.
But then, our modern military rifle fires a much lighter cartridge than the old Garand. Thats 5,56NATO vs. 30-06, the latter one has more than twice the muzzle energy of the former one. Should have mentioned that in my post.

Quote

whereas modern artillery must handle 100% of the recoil themselves right?

Every system that launches a projectile out of a barrel must handle 100% of the resulting impulse itself. Revolver, artillery, mech, spaceship,... doesn't matter.
Artillery pieces already can, for example, use hyropneumatic damping to "spread" the recoil over a much longer time.

Recoil wouldn't topple over a mech, not even today, that could all be easily taken care of in the future. Worst case is that the robot would have to take a step backwards, like a human that gets pushed back.

Btw., MWO autocannons don't even seem to use muzzle brakes.

[Nightbird]

occusoj, on 10 March 2018 - 05:58 PM, said:

Yes, about 15%.
But then, our modern military rifle fires a much lighter cartridge than the old Garand. Thats 5,56NATO vs. 30-06, the latter one has more than twice the muzzle energy of the former one. Should have mentioned that in my post.

Fixing the 5.56x45mm NATO round then for comparison,
I'm no gun historian, but the M16A1/2 weighs 8-9 pounds, and today you can find rifles @7.5 pounds loaded (30 rounds)?

occusoj, on 10 March 2018 - 05:58 PM, said:

Every system that launches a projectile out of a barrel must handle 100% of the resulting impulse itself. Revolver, artillery, mech, spaceship,... doesn't matter.
Artillery pieces already can, for example, use hyropneumatic damping to "spread" the recoil over a much longer time.

Recoil wouldn't topple over a mech, not even today, that could all be easily taken care of in the future. Worst case is that the robot would have to take a step backwards, like a human that gets pushed back.

Btw., MWO autocannons don't even seem to use muzzle brakes.

The system for the mech can be the Autocannon + the mech is closer to what I meant. Especially for arm mounted weapons, I see the arm swinging back and therefore removing the need to build "muzzle brakes" and "hyropneumatic damping" into the weapon itself, reducing weight.

[Chados]

The 100 ton über-Commando looks like a badass assault mech.

I want one.

[Jungle Rhino]

MadBadger, on 04 March 2018 - 05:58 AM, said:

I have no idea what PGI based their scale calculations on, other than 'we think this looks about right'. Regardless, we have what we have and I suspect it will never change.

Re-skinned weapon balance dartboard

[Sebaztien Hawke]

But... tonnage and volume are not the same? There could be internal differences with mass? (Endo steel is an obvious example)

Lights seem pretty small to me when they are running around at 120kph+ and I have 500ms latency...

Just from the artistic point of view, I don’t think scaling needs to be strictly volumetric, but since this a real time video game I suppose it might be part of a balance issue. But is it so wrong for some ‘mechs to have better silhouettes? It’s not like they have actually built them with a viable myomer structure either.

[kapusta11]

What are you talking about? Mass has everything to do with volume, as well as density. V=p*m, where V is volume, p is density and m is mass.

The problem is that MWO is a video game. People can buy into 10-15% bigger or smaller mechs if it improves gameplay.

[Kroete]

Old MW4 Ranger, on 10 March 2018 - 06:15 AM, said:

only by same Material ..and thats is nothing by Complex Vehicles...a Arm with a Weapon has aother Desity as one arm with ammunition or Heatsinks ,with a full modelling Hand or only a Weaponspylon...a old TV from 1950 has other Weight as a New LED Monitor in same size...a Marauder has a special Armor thats only the Marauder has ,all mechs have differnet Aurtocannons with different mechanics and calibbersfrom different Companys...a Quetzlocoatlus Pterosaurus with 12 m Wingspan as a Different bonestructur as a Titanosaur or Liopleurodon

You should better use an example from some similar dinos, but in different scales.
You are trying to compare a osprey with bucket excavator and a submarine.

About weapons in mwo: the autocannons are all different, but they all have the same space and wheight.
For the mechs structurs, they have 3 different materials with different densitys to choose but dont make them bulkier outside because they go in the internal slots, the same counts for armor, dont make it overcomplicated.


But back to volumetric scaling :

1 box, 1x1x1m, 20 tons, 1m³ volumen,
1 box 1,3x1,3x1,3m 43,9 tons, 2,2m³ volumen,
1 box, 1,5x1,5x1,5m, 67,5 tons, 3,4m³ volumen,
1 box, 1,7x1,7x1,7m 98,3 tons, 4,9m³ Volumen,
1 box 2x2x2m 160 tons, 8m³ volumen.
(Dont know if the math is right, was done after wakeing up without a tea or smoke.)

Lets use the same density for all mechs and our example locust has a volumen of 1m³ and is our base scale.
Now
a cicada would have double the volumen,
a catapult tree times the volumen and
a atlas five times the volumen of our locust.


For the mwo comparsion, you need to set one mech as base scale,
get its volumen and weight and calculate its density.
If you have the base density for all mechs and know their weights,
you can calculate the volumen they should have.
Then just scale them up or down until they reach the calculated volumen.

If you want it more realistic, you need also to increase the structure % of the bigger mechs,
because doubling a structur does not increase their streght as much as their weight increases.
Our atlas then would not be fat, but it would have heavy bones.

Edited by Kroete, 11 March 2018 - 03:02 AM.

[Y E O N N E]

Nightbird, on 10 March 2018 - 02:53 PM, said:

I'm pretty sure pistols and rifles have gotten a lot lighter and also perform better than 80 years ago...

Nightbird, on 10 March 2018 - 04:26 PM, said:

And if you hold the number of grains and projectile weight/size constant... no improvements in reliability, weight, fire rate?

The felt recoil from the same round will be worse because there is less mass to move. Rate of fire is a function of the spring rates and the mass on the breech block, and it doesn't take much alteration to those to radically change the rate. And if you only increase the mass by a few dozen grams, you can either end up with an uncontrollable rate of fire or a really slow one.

Edited by Yeonne Greene, 11 March 2018 - 09:26 AM.

[Nightbird]

In the OP, I noticed that some of the mechs were floating further off the ground than others, so I fixed them up. The heights should a little more representative of volumetric scaling now.

Yeonne Greene, on 11 March 2018 - 09:23 AM, said:

The felt recoil from the same round will be worse because there is less mass to move.

Regardless of the weight of the gun, shouldn't physics require 100% of the recoil (horizontal) be absorbed by the shooter's arms (pistol) or shoulder (rifle)? The rise (recoil vertical?) may be worse though because the gun is lighter, and that's due to gravity.

Yeonne Greene, on 11 March 2018 - 09:23 AM, said:

Rate of fire is a function of the spring rates and the mass on the breech block, and it doesn't take much alteration to those to radically change the rate. And if you only increase the mass by a few dozen grams, you can either end up with an uncontrollable rate of fire or a really slow one.

Temperature tolerance affects rate of fire, the hotter the barrel can withstand without warping, the longer a high rate of fire can be maintained and the shorter the cooling period (larger delta with ambient temperature equals more heat transferred per second). Though.. material science can also improve heat dissipation for the same mass or surface area or both.

Edited by Nightbird, 11 March 2018 - 09:35 AM.

[Y E O N N E]

Nightbird, on 11 March 2018 - 09:28 AM, said:

Regardless of the weight of the gun, shouldn't physics require 100% of the recoil be absorbed by the shooter's arms (pistol) or shoulder (rifle)? The rise may be worse though because the gun is lighter (I mean the upward movement, not familiar with all gun terms), and that's due to gravity.

Hence why I said "felt recoil" in the edit. A shorter, sharper kick is felt with a lighter weapon and that means less consistent accuracy and increased shooter fatigue. The amount that the muzzle rises can be managed by using a muzzle brake to direct the gasses upwards (and the muzzle downwards). It can also be managed by reducing the length of the moment arm the recoiling barrel has to act on (e.g. a pistol barrel is mounted high over your hand and so it wants to wheel your hand upward; if the barrel were mounted closer to your pinky, it would be more inclined to push straight back).

[Nightbird]

Yeonne Greene, on 11 March 2018 - 09:33 AM, said:

Hence why I said "felt recoil" in the edit. A shorter, sharper kick is felt with a lighter weapon and that means less consistent accuracy and increased shooter fatigue. The amount that the muzzle rises can be managed by using a muzzle brake to direct the gasses upwards (and the muzzle downwards). It can also be managed by reducing the length of the moment arm the recoiling barrel has to act on (e.g. a pistol barrel is mounted high over your hand and so it wants to wheel your hand upward; if the barrel were mounted closer to your pinky, it would be more inclined to push straight back).

Those are all fine these limitations are in the shooter after all, and a mech managed by a targeting computer would not be as affected = reduced weight of the weapon?

[Zigmund Freud]

Remind me, why don't we just normalize by lights? (Actually first make lights about 25% smaller, and then normalize). Lights are still somewhat ok, mediums are almost not affected by rescaling, heavies are good, and assaults become much more viable, because same armor, but harder to hit. Also, less crotch-hugging from lights, because assault crotches are lower now.
So basically increased TTK assaults, TTK the rest classes is same. Good, right?

[MW Waldorf Statler]

Kroete, on 11 March 2018 - 02:03 AM, said:

You should better use an example from some similar dinos, but in different scales.
You are trying to compare a osprey with bucket excavator and a submarine.

About weapons in mwo: the autocannons are all different, but they all have the same space and wheight.
For the mechs structurs, they have 3 different materials with different densitys to choose but dont make them bulkier outside because they go in the internal slots, the same counts for armor, dont make it overcomplicated.


But back to volumetric scaling :

1 box, 1x1x1m, 20 tons, 1m³ volumen,
1 box 1,3x1,3x1,3m 43,9 tons, 2,2m³ volumen,
1 box, 1,5x1,5x1,5m, 67,5 tons, 3,4m³ volumen,
1 box, 1,7x1,7x1,7m 98,3 tons, 4,9m³ Volumen,
1 box 2x2x2m 160 tons, 8m³ volumen.
(Dont know if the math is right, was done after wakeing up without a tea or smoke.)

Lets use the same density for all mechs and our example locust has a volumen of 1m³ and is our base scale.
Now
a cicada would have double the volumen,
a catapult tree times the volumen and
a atlas five times the volumen of our locust.


For the mwo comparsion, you need to set one mech as base scale,
get its volumen and weight and calculate its density.
If you have the base density for all mechs and know their weights,
you can calculate the volumen they should have.
Then just scale them up or down until they reach the calculated volumen.

If you want it more realistic, you need also to increase the structure % of the bigger mechs,
because doubling a structur does not increase their streght as much as their weight increases.
Our atlas then would not be fat, but it would have heavy bones.

yes after the abstract Construction TT rules (thats different in each Game ..seeing MW3 ...Mw4...MWO) and thats have nothing to do with the Concept Arts thats not make to after construction Rules ..only to artist Minds...by the Artists all the Weapons have nothing Weight, Size or Loading Mechanism ,Ammunition Boxes or somthing ..the Concept arts only empty Fantasy Hulls ...and a 180t Maus have not the Density like a Sherman Tank ...thats the Problem between Free Concept Art (seeing many Mechs in old TROS thats never going a Step while absolutly imbalanced)..very abstract unrealistic construction Rules and gaming Rules..for realistic Rule we must have 4 Basic x3 D Sceletons with empty Slotrooms for the class, 3D Armorplates and 3D Weapons Engines and now constructed this Equipment really i the Sceletons (like the old earthsiege Game)...in Concept Arts a Light can carry a 2 AC20 when the Artists thinking thats its to the rules ...and shrinked the AC 20 of the Size of a MG or make a MG in the size of a Aotocannon ...the concept Arts have nothing Construction Rules

In MWO we can take heavier Weapons in lights as in MW4 ...havier Engines...each MW game very different in mW4 you can spare Tonnage and the Mech is a little faster with the same Engine and we have a very different (and better) Slotsystem.

Edited by Old MW4 Ranger, 11 March 2018 - 10:19 AM.