17 replies to this topic

[AWOL 01]

I've been thinking about how many people, even on these forums, think that mechs wouldn't have a place on the battlefield, and I think that's mainly because mechs are portrayed pretty unrealistically, so I decided to make my own model of what I think a mech would look like if it were being used today. I'll try to finish more models later on but for now this is mainly just a Leopard 2 turret on top of a pair of legs. While mechs wouldn't be the supreme rulers of the battlefield that they are in the Battletech universe, they would have a place next to modern tanks and infantry. Let me know what you think about the design and how I can improve it!

Dimetric View


Front View


Right Side View


Top View

Edited by AWOL 01, 20 November 2014 - 10:50 AM.

[Hex Pallett]

Hate to be "that guy" but your starting point is wrong.

Now, I'm no physicist, but to understand how a thing can walk on two legs, you need to think of its center mass, namely how the weights are distributed/focused. As far as I know, the center mass should be as close to ground as possible, and the two supporting legs should also be relatively close to each other.

We human have a very balanced center mass - symmetric build, weight of upper body lies on the bowel and heavy, muscular legs. We have complicated muscles and bones and arm-flings and stuff to keep our upper torso balanced.

And most importantly, our legs are very close to each other, and when we walk and shift the weight between our legs, where the wight goes to the ground is never far from our center mass.

"But", you may ask, "there are things that have leg being rather far apart, like...ostrich!"

I know, and that's why we need to take a look at this:



You see? The majority of an ostrich's body is even lower than that of a human's!

(and this pic also serves as a perfect demonstration of how your, as well as every single bird-leg 'mech in MWO, are completely unrealistic. Notice that bird-legs do not have "reversed joints", they have short thighs and veeeeeery long feets.)

Not mentioning that an ostrich's wings' sole purpose is to aerodynamically balance itself at high-speed.

So, assuming your mech could walk, despite its impractical reversed joints, it would walk like a very fat man, constantly shifting its weight from left leg to right leg as it moves forward. Not only is it terrible for accuracy when firing its guns, it also looks really, really nasty.


TL;DR: don't design a "realistic" mech thinking about how it looks, think about how it walks.

[AWOL 01]

I know exactly what your saying, I'm working on correcting the design right now. Mechs are always shown with the leg coming straight out of the from the hip, rather than below all of its weight, which would put an enormous amount of shear force on the joint. I'm in the process of making the legs attach more like Asimo's.



I modeled the legs that way because it was easy to do quickly in SolidWorks (I used the AT-ST as a template ) but I'm going to add a joint so that the current "hip" is actually the knee. Most of the mass on the model is at or very near the hip joint, but maybe I should add some more? I also made a model of a Leopard 2 on treads to give a comparison of size.

[AWOL 01]

Okay so here it is with the legs fixed:


It's a little taller than I would like, but here's a comparison:


Front View


The legs attach directly below the platform the turret rests on. The degrees of freedom are shown below.

[Hex Pallett]

That makes a lot more sense to me. The only thing I'm not so sure about is the "suspension" - I mean, in animals the muscles themselves also serve as suspensions. But that depends on the technology level you have in mind.

[Brody319]

I imagine the first mechs will be quad legged or tri-legged. For stability when firing a large gun. Since your model looks pretty top heavy it might topple over.

I think there will be 2-3 different kinds that are vastly different.
One would be a city mech, similar to what you designed but instead of a big gun it would be mounted with large caliber machine guns so it wouldn't knock itself over. Would probably be pretty fast if it wanted too.

Second would be an assault like mech, would be much bigger. with fat feet to hold it up. That mech would be good for large caliber tank rounds since it would be slower and better weighted down at the legs.

Finally I imagine there would be something much bigger, but would have to lower support pistons in its legs, similar to a firetruck that would give it much better stability and basically be a mobile long range mech. Likely with missiles, artillery shells, and would stay far away and bombard the enemy.


So you would see the second and first mechs in city warfare lightly fighting tanks and people in buildings, while the final one softens the enemy and provides long range artillery. Probably will be limited in numbers and slowly increase as they improve it.

[Grantham Besat]

No walker will mount equal armor or armaments to a tank of equal technology. The only way to make one useful is if it is supper mobil in mountains. City battles are no place for any afv regardless of it being a walker. To be useful in mountains and cities puts a size limit on your mech. They will be like a BT proto mech or elemental. You cant trump physics so tracks will always rule the front lines when you want maximum armor and firepower.

[AWOL 01]

Helmstif,
The double-sided arrow halfway down the leg on the last picture is where some sort of shock absorbing device would be. On this model there is a flat spring along the back of the leg, so as the mech is walking it will bend slightly to absorb the impact. It will also use carbon nanotube muscles, which would act similarly to an animal's muscles. I wrote a paper on these artificial muscles and they're pretty incredible. They're very light (most of their weight comes from the paraffin wax they're coated in), extremely powerful (85x more powerful than biological muscles), and require very little power (they can be designed to contract using the sun's rays or heat from your hand). They're pretty costly right now, and they haven't gotten multiple bundles to work together yet, but they're estimating they can mass produce them and have bundles working in unison by around 2020. With all the advantages they have, walking vehicles would become much more viable. Also, because they produce a linear force and not a rotational force, they couldn't be used to propel a tank or other wheeled vehicle. Another interesting thing they're working on is making the muscles "heal" or bond back together when damaged. Combined with the nanotubes' already impressive strength, the legs would be very well-protected rather than being the mech's weak point.

Their usage is the major factor in their design, so if they're going to be a front-line unit they'll need heavier armor, a lower profile, and a heavier main gun, like the Leopard 2 turret used above. If they're going to be more of a scout unit (think attack helicopter on legs) they'll need longer legs for a longer stride and more speed, and a higher vantage point, with a turret more like a Bradley or another IFV with a 20-30mm cannon and a couple TOW missiles. With the complexity of the machine it would probably require a crew of at least a driver and a commander/gunner.

Brody319,
The advantages to using 2 legs are that they are better at travelling long distances because it uses less energy, and that they would be much faster. In the animal kingdom, animals on 4 legs usually move faster because they have a flexible spine, but this would be difficult to have in a vehicle that weighs many tons. Plus ostriches have been known to outrun racehorses, so it's all in the design. A quad-legged mech would have a place though, especially as mobile artillery pieces, but not so much tri-legged, because it would be harder for them to move without the symmetry of having 4 or 2 legs. Also, I would imagine the mech would have to have a system that absorbs a majority or the recoil, along with the mech bracing itself. When a person fires a rifle they lean into it, separate their feet, etc., so the mech could do the same possibly? You are exactly right on there being different kinds of mechs. There isn't just one type of tank, the military uses MBTs, light tanks, IFVs, and reconnaissance vehicles so it would only make sense to have heavily armed and armored quad-leg mechs along with lightly armored, quick moving, bipedal recon or fast attack mechs.

[ChapeL]

I always imagined "mech" type vehicules would be closer in size to gears from the Heavy Gear universe. Incidentally, as was stated above, Proto mechs from Battletech. Something agile and "fast" over very broken terrain to be used as a means of holding ground that airborne units cannot do.

[Grantham Besat]

Yup profile is a killer for the walker concept past a certain size. Those muscles sound great for an armoured suit.

[AWOL 01]

I would say the maximum height for a mech to be viable would be no more than 20 feet. anything past that and the costs will outweigh the benefits. Gears are a good example, but the first mechs probably won't have arms or look extremely humanoid. The CNT muscles that they use will provide enough protection and keep the weight low enough that a mech could support pretty heavy weaponry, Armored suits/exoskeletons will probably be used as well, but I don't know if they'd have enough surface area to mount heavier weapons on, since they'd be pretty small, probably around 8 feet.

Thank you for all the input! I'd like to make another design but before I get started I'd like your input on how tall it should be, its basic shape, the weapons it will mount, the crew number, what its purpose is, and anything else you can think of.

I like the basic shape of this one. I'm thinking its around 15 feet tall.


This could be some sort of heavily armored suit? The torso wouldn't rotate 360 degrees but the pilot could sit in the main body and "look" using a head unit?


The legs wouldn't really work on this one but the layout is nice. A little tall though, around 25 feet.


Here is a real life bipedal robot that the legs could be modeled after.


And another. This one's small but it's more mech-like and participated in Mech Warfare at the RoboGames.


Or if the mech is 4-legged should it walk like WildCat, which would give it more speed and allow it hold more weight,


Or more like a spider so it's lower to the ground and more stable on rough terrain and when firing?

[Tustle]

AWOL 01, on 21 November 2014 - 08:26 AM, said:

And another. This one's small but it's more mech-like and participated in Mech Warfare at the RoboGames.

Funny you show that one, that particular bot's supposed to be modeled after Battletech's own Mad Dog/Vulture; the maker mentioned this in a 2009 article on Mech Warfare in Robot Magazine. He even named it 'Hagetaka' after the Japanese term for 'Vulture.' From what I remember reading however, there were some sort of issue in getting it to walk...and as far as I can tell from match footage, the mini-Vulture never got to fight. And at the end of the day for Mech Warfare matches there was just no beating the stability and agility quads had over what few bipeds actually entered in the classic leagues.

At least it was able to stand and aim tho...

Edited by Tank Man, 21 November 2014 - 09:17 AM.

[zagibu]

Mechs in real life wouldn't replace tanks. They wouldn't be about armor and weapons, but about versatility. Support and specialistst, mainly. Tearing down things, clearing away rubble, reclaiming damaged equipment, etc. Maybe with some weapons for self-defense, if armed at all.

[AWOL 01]

Tank Man,
I thought it looked familiar! Sad to hear it didn't get a chance to compete. You are absolutely right about the quads doing better but I think it was because they're so much easier to build since they're inherently stable and easier to program. Both have their pros and cons so I think we'd see a mix of biped and quad mechs on the battlefield. The problem is getting someone to fund the development. When the Wright brothers invented the airplane the US wanted nothing to do with it because they couldn't see it's uses. Now they're a major part in modern warfare. If someone supplies the funds to do the research we could definitely see some form of mech in our lifetime.

zagibu,
There's no way tanks would be replaced by mechs, but I do think they'd work together. Are you thinking of them being used by units like the Seabees? That could definitely be a possibility.

[StompingOnTanks]

Very, very interesting design! I especially like the second version.

Adding to the discussion - yes, I think mechs would be valuable on the modern and future battlefields. Here's why.

1 - Unsurpassed terrain navigating. The benefits of legs in rough, unpaved terrain is obvious - just look at nature. One of the greatest advantages you can have in a battle is the ability to get big guns into a tactically advantageous position. A vehicle that can walk, run, step over or around obstacles and perhaps even jump and climb would be the king of doing exactly that.

2 - Agility and controlability. Driving a tank requires two throttles; driving a car requires pedals and a steering wheel, but a mech - being a bipedal system like humans - could be made as easy to control as a first person shooter video game. All you need are two joysticks, one for movement and one to aim/look around, and buttons on the joysticks for weapons and advanced movement control (jump/crouch/sprint etc). A 10 year old Call of Duty player could probably control that. The result? Relatively little training required to operate it and drastically reduced pilot stress, the result being improved crew performance and possibly only needing one pilot to operate it. This in turn reduces the cost and profile of the entire vehicle.

Bipeds are also especially agile because of physics reasons I don't feel like writing an essay about right now (it's basically the concept of inherit instability that jet fighters use to increase maneuverability, applied to mechs, but there's more to it than that). Bipeds can move in any direction, turn almost instantly, change direction while moving while still facing the same direction, and alter their ride height while moving (kneeling/crouching while walking). As a result, assuming we have balance, traction, and ground pressure issues all worked out (which we should if we're trying to build mechs anyway), you have a vehicle with excellent handling and agility for close quarters combat or in tight spaces. This by itself already gives mechs a huge advantage in urban, forest, or jungle combat against wheeled or tracked equivalents because you don't have to actually turn the vehicle itself. This means a mech could quite literally run circles around tanks in close combat where there is little maneuvering room.

3 - The effect on enemy and friendly morale.

Imagine you're an infantry soldier in a future war. You're fighting to defend a city, armed with a power suit, a rifle, and grenades, and you and your squad is trying to advance. You sprint, round the corner, and stop dead when you see this thing.

Spoiler

I don't know about you, but I'd immediately soil myself and scramble for cover if not outright run in the other direction.

And scaring the enemy into retreating is always preferable to having to outright kill them. In fact, that's more or less what war is about; scaring your enemy into retreating or surrendering so you can win with minimal casualties and ammo spent on your side.

That being said, mechs will never replace tanks, because tanks have a tiny profile, small surface area and extremely low weight distribution on their side. Therefore, they will always have heavier armor for a specific weight class. So unless we see a massive shift in technology or military tactics, mechs will never surpass tanks in the "charge straight into enemy fire and crush them with raw brute force" department, unless you want to build a ridiculously huge mech to do it, which would be prohibitively expensive and heavy to actually deploy in a battle. I bet the Russians would still try it.

So if a mech and a tank do fight, the mech is going to have to use guerrilla tactics to win, or it will serve a role similar to WWII tank destroyers; wait in a nice concealed spot and snipe from extreme distance so your thinner armor doesn't become your death.

Edited by StompingOnTanks, 21 November 2014 - 01:12 PM.

[Lily from animove]

something tells me your mechs trying to shoot would probably drop backwards by the power of the shot.

[AWOL 01]

StompingOnTanks, on 21 November 2014 - 01:11 PM, said:

Imagine you're an infantry soldier in a future war. You're fighting to defend a city, armed with a power suit, a rifle, and grenades, and you and your squad is trying to advance. You sprint, round the corner, and stop dead when you see this thing.

Spoiler

Pretty terrifying if you ask me. And concerning the recoil, the mech isn't as fixed as a tank is. It can brace itself, and it can catch itself if it is falling. That's the mech's advantage: its mobility. If you skip to the 25 second mark in this video you can see how well these 2-legged vehicles could balance themselves.

[AWOL 01]

Alright so I made a new design and actually took the time to think through it first. It stands about 12 feet tall and is armed with a 30mm cannon and 3 TOW missiles. I haven't added any sensors or anything and a canopy just seems kinda dumb, but I don't know how else the pilot would see. Since it's lightly armed and relatively small I figured it only needed one crew member. The idea for the "elf feet," as my sister called them, came from prosthetic running legs (blades) so that at higher speeds the mech will run more on its "toes" than on its heels, similar to an ostrich. At lower speeds the larger surface area will help support it on softer ground. Feedback is appreciated!

Front View

Spoiler

Side View

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Top View

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Standing

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Crouching

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Kneeling

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Running

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