Would bipedal mechs actually be useful?

[Forboding Angel]

I dare say that 4 legged mechs would be much more useful than bipeds. Assuming that those mechs have more than 2 joints per leg to allow for maximum climbing potential.

Ideally joints could be locked in place to make things like running less arduous.

[MetalSucker]

I am thinking wild feline style running/jumping is optimal, the number of joints required is insane but it would actually get to dodge things so it's a trade-off between ruggedness and agility. Shield technologies would require power generation/batteries and that means a really large unit with today's tech - and even then I don't really know of a feasible energy shield thing, I've seen some cloaking things though on the internets.

OTOH quad copter acrobatics:

http://www.ted.com/talks/raffaello_d_an ... uadcopters

Aggressive quad maneuvers:

https://www.youtube.com/watch?v=MvRTALJp8DM

<no I don't sell quadcopters>

I'm having serious doubts a human pilot/driver can withstand those G forces / landing shocks (should it be bigger than a toy). The whole metal robots mindlessly & automatically fighting eachother thing seems more plausible each day.

I think that as far as the UI goes, Pacific Rim got it right as far as sci fi mechs go, physical feedback is a major issue on one hand, and there's no reason to build them into a human-like shape unless there's a neural connection already used to that shape that's needed to control it.

But as far as games go, I think space marines and giant robots are more fun.

[PicassoCT]

The additional problem is, that with so much weight on two legs, allmost everything not solid concrete- becomes a kind of swamp..

Mechwarriors in citys, would be struggling most of the time to get there sunken in legs out of cannalisation and rooftops.

[Forboding Angel]

Not to mention sewers and catacombs long forgotten.

[PicassoCT]

"LanceLeader, i would attack - but im stuck in a car, and his owner has made a real evil trap with epoxid glue.."

[LordMuffe]

The additional problem is, that with so much weight on two legs, allmost everything not solid concrete- becomes a kind of swamp..

Mechwarriors in citys, would be struggling most of the time to get there sunken in legs out of cannalisation and rooftops.

doubt that, its just a question of feet-size: an elephant weights about 5 tons with its 4 feet covering roughly a square-meter together. And you never hear that they have any problems walking through cities... ...

[PicassoCT]

They have allready trouble with going up slight elevations, as that means additional energy, they have to reconsume. And a mech is not 5 tons.

A mech is in the thirty ton range like a tank.

[smoth]

Bipedal biomechs are the backbone of modern warfare. But would upscaled ones be sufficiently better? Probably not.

There are fundamental issues with making 90-ton things that walk on fragile sticks with narrow contact area.

F22
Length: 62' (19 m)
Weight: 43,430 lbs (19,700 kg)

according to wikipedia:
In the United Kingdom the ton is defined as 2,240 pounds(long tons)
1.938839285714286 tons..

then there is the abrams..
Length: 32.04' (9.77 m)
Weight: 43,430 lbs (19,700 kg)
Tonage: 62!

made up stats for the 18meter rx78(gundam)

Head Height: 18.0 meters
Max Weight: 60.0 metric tons
Standard Weight: 43.4 metric tons

even when you consider the f22 is a fighter craft, say the real weight of the rx78 was 10x that... we are talking what? 20 tons? If you used the abrams as a base,(64/9/4 = At, At*9=Nt, Nt*2 =144 and some change). Of course that is assuming the thing is solid armor like the abrams..

so the wild range of 20-144 tons for a 18 meter mech... and they have the baseline(standard weight) of the rx78-2 at 43.4. So that is a fairly reasonable weight..

most people see mechs and think of fucking HUGE things the size of godzilla. they are not. I have a bunch of scale comparison images but honestly, since I have not worked on GRTS for a long time they are buried in my forum and I don't remember where I have them stored. Either way...

scale comparisons one guy did
http://quentinlau.blogspot.com/2011/04/ ... rison.html

[LordMuffe]

They have allready trouble with going up slight elevations, as that means additional energy, they have to reconsume. And a mech is not 5 tons.

A mech is in the thirty ton range like a tank.

is it? http://en.wikipedia.org/wiki/BattleMech ... 20-100t ... yeah the feet would be a bit bigger... but also harder so more presure isnt that much of a problem for the feet themselves.

example 30t mech:

Don´t know how much presure most city streets over sewers can withstand, but considering that you need roughly 100 times the space a motorcycle (~350 kg) uses ( one palm per wheel (http://de.wikipedia.org/wiki/Reifenaufstandsfläche)) to get the same presure while standing ( ~0.65 m^2, even less than the 5t elephant has) , its not to hard to imagine that with bigger feet it wouldnt crack the surface of the road even while moving/running). Of course that might be wrong, couldnt find good numbers for the pressure resistance of streets. And while the surface might withstand the pressure, the sewer under the street might not withstand the wight of the mech ( manholes as specific problems ).

So i would say, that there would be more trouble with wet earth than with streets or stone as ground for mechs, just like it is for tanks. So tanks don´t have to worry over the additional force stomping around causes. Though, after a quick fly-by over the net it seems that in the human walk-cycle you don´t go over 2-3 times earth gravity on half the space with half the weight, and for only a short period of time. So unless im completely wrong with the numbers, its not a "real" problem.

regarding the energy... if we are at the point that computation power isn't a problem anymore to handle the mech, than surely the energy source won´t be much of a problem either. Also: horses have quite some trouble catching up to fossile fueled machines, even those lighter then themselves. i don´t see the argument here.

[PicassoCT]

A tank has to be quiet often repaired. I presume a mech has that problem too, unless you have selfrepairing feet..

What could be interesting is a tank, that has legs in addition, allowing it to have all the tank benefits (flat profile, speed , and in a city to fall back on foot.

[Anarchid]

so the wild range of 20-144 tons for a 18 meter mech... and they have the baseline(standard weight) of the rx78-2 at 43.4. So that is a fairly reasonable weight..

most people see mechs and think of fucking HUGE things the size of godzilla. they are not. I have a bunch of scale comparison images but honestly, since I have not worked on GRTS for a long time they are buried in my forum and I don't remember where I have them stored. Either way...

Some things i've realized while reading your post:
1) A 18 meter mech weighting 30 tons implies its density is less than that of water, lest steel.
2) Materials capable of withstanding the wear-and-tear of bipedal locomotion while being so lightweight are interesting.
3) It is possible that in a world where such X-factors exist, legged mechs are somehow more energy-efficient.

However: if you could make a denser unit with a lower profile and the same firepower, you'd likely gain advantages. Or same legged locomotion, but with a lower profile?

It is undoubtedly possible to imagine a world where those would make sense, but that world is usually very far from ours and rather specific.

That is, all such worlds pretty much have to be specifically tailored to make mechs useful.

[Forboding Angel]

As mentioned before, weight distribution matters as well. In an abrams that weight is distributed all along it's frame.

In a mech, all the weight is distributed in the feet, so depending on how large the feet are, you could end up with the equivalent of needles punching through streets every time it takes a step (hyperbole, but you get the idea).

[smoth]

However: if you could make a denser unit with a lower profile and the same firepower, you'd likely gain advantages. Or same legged locomotion, but with a lower profile?

yeah, that is why most of the mechs in my game are pretty much 40ish feet tall.

[smoth]

Also this is an rx78 next to an a10 of the same scale. I have a bunch more crap but yeah, this is all I can find

[MetalSucker]

Here we go, state of the art:

2014 RoboCup SPL Grand Final: rUNSWift Vs HTWK

https://www.youtube.com/watch?v=dhooVgC_0eY

Feeling threatened already ...

[KDR_11k]

(sorry for the thread necromancy)

So Smoth's examples show that making a mech stand up might work. However even if you get a standing mech "for free" you still wouldn't want to build one for military purposes.

Tanks are flat wedges for many reasons.

One is that the smaller you are the harder you are to hit and the more of yourself you can hide behind cover. Obviously not getting hit is the best defense. Humans go prone when shooting at long ranges because that makes them smaller targets. Imagine a prone mech, remove the legs it's not using, add treads to the underside to let it move prone and you have a tank anyway.

Next there's armor. I don't know the exact values but modern tanks are said to have about 1 meter thick front armor on the body (more on the turret). Multiply that with the frontal profile of your mech and you'd need insane amounts of armor to get a similar level of protection. And you need similar levels because anything less (previous gen tanks were something like 70cm armor thickness I believe) means a tank cannon can pierce your armor. Now of course not every vehicle needs to fill the battle tank role and withstand tank cannon fire but with something as big as a mech you're going to be slightly larger than a family home and thus take a lot of fire. Hell, at the size of a mech you'd have trouble getting enough armor thickness to stop RPGs. Planes can get away with their big profiles when seen from below because they're fast and far away so they are much harder to hit. Your mech won't be.

Then there's the angle of deflection. Tanks are wedge shaped because when shots hit at an angle sharper than maybe 45° their force is partially deflected and thus they damage the armor less. Your vertical mech would not get that benefit on many surfaces.

Of course arms aren't good gun holders compared to turrets with their 360° traverse and centered position (which helps with the massive recoil of a tank cannon) but not all mech fiction uses jointed arms.

Another thing is camouflage, you want to hide your vehicle from enemy recon (especially aircraft) when you're not fighting so nobody drops a bomb on your head. Kinda difficult when your vehicle is as tall as a tree in a forest.

Now let's think about the legs:
Two large legs are giant targets and if one breaks your mech is immobilized and probably unable to fight (since it falls over). Of course a tank with a destroyed tread will not drive much either but at least the gun stays on the top.

Being upright can't be good for aerodynamics, a 12 meter mech would probably be slowed a lot by air resistance.

A spider configuration would of course work. I'd go for more than just 4 legs so that a broken leg or two will not immobilize the vehicle, the legs would keep the body of the vehicle fairly low to the ground though the highest point of the legs should probably not reach above the turret or you lose a lot of firing angles, I guess that would limit the movement speed so it might not actually be an improvement over a tracked tank. Also the legs would need to have at least enough armor to withstand small arms fire or you'd lose the point of the tank entirely. I don't think you could build it to have spider legs in addition to tracks (maybe in addition to wheels) since tracks seem to take up pretty much the whole side of a tank with all their little wheels everywhere.

Of course unmanned vehicles are preferrable, they let you save a lot of space by not needing a crew compartment and stuff like life support systems (gas filters and stuff). Still need a human crew nearby for maintenance after the battle.

Fictional universes usually fudge it by giving mechs armor, speed and firepower far higher than their size and weight would allow. Generally tanks seem to have like 2cm thick armor in fiction.

[PicassoCT]

The natural enemy of tanks is the rocket or bazooka - fired from helicopters - which show a behaviour of sneaking up behind hills , peaking out and firing.

No reason given thus far by KDR , why a rocket-rodcricket stalking the terrain wouldnt win against a tank.
And while we are at it.. anything that keeps dangers like tanks or planes far away and at bay is going to win the battles of the future. So a carrier that can stalk the lands and have anyhting within miles supressed with robot drones, can look ridiculous to the max, and nobody will care, cause nooboditys wont be there.

[8611]

F22
Length: 62' (19 m)
Weight: 43,430 lbs (19,700 kg)

according to wikipedia:
In the United Kingdom the ton is defined as 2,240 pounds(long tons)
1.938839285714286 tons..
...
even when you consider the f22 is a fighter craft, say the real weight of the rx78 was 10x that... we are talking what? 20 tons?

this.
ten times this.

[MetalSucker]

https://www.youtube.com/watch?v=9qCbCpMYAe4

6:05 for awesome human size walking mech, 8:42 as well (or just watch the whole thing), some of them are creepy.

[Anarchid]

even when you consider the f22 is a fighter craft, say the real weight of the rx78 was 10x that... we are talking what? 20 tons?

I'm getting confused by the imperial weight units, but isn't 10*20t = 200t ?