Is it possible to build a "mecha" with today's science? With some limitations of course?

[Archinist]

Every other thread on reddit, quora or stackexchange on this topic almost always has a super-futuristic idea of the "mecha" we're supposed to build. It's 5 stories high, the motors can reliably punch through solid concrete, it's held up by two legs, it can climb, sprint fly etc etc.

Okay, what if it wasn't supposed to do any of that? Let's say it's about the same height and width as a small tractor, a large forklift or a skidsteer. It has the option of being fully enclosed and armaored for military LARP (no army would use it).

The armor isn't 10x stronge then any real world material. It's maybe a few mm of hard steel at the thickest parts, the rating is for .308 ball or lower.

If two legs are too difficult then maybe it's on wheels or tracks, goes about 5 - 10 km/h, it can't fly or leap or sprint or burrow underground.

Basically it's a regular utility vehicle but styled like a "gundamn mecha". Instead of having a front "arm" that lifts 10 tons, it has two side-facing arms that lift like 1 or 2 tons each? Or less/more? I don't know.

Question is, why isn't this possible? I've done some research and there seems to be a few vehicles like this that did exist at one point (the Megabots mech, the Hacksmith's powerloader (Aliens) mech, a quadwheeled mech with dubious arm strength and supposedly the US air force had a logistics "mech" at one point (It's in a popsci article...?) plus a Japanese rescue "mech" that resembled a forklift with two arms. No idea if the US AF mech existed there's not much evidence besides a popsci article.

Yeah, it feels like it's physically possible, but you'd have to find a bunch of personal project engineers and give them like $100k and hope for the best.
I'm sorta surprised that none of the eccentric billionaires have tried to popularize this yet. It seems a whole lot cheaper to build, heck, some Youtubers built one out of their mechan. workshop for like $50k, and you have billions poured into 25 km-long skyscrapers in the desert and AI chatbots lol.

[Jaglavak]

Sure, you could. But there are a few real world limitations. When you make things large, they get heavier faster than they get stronger. Basically as if the materials got weaker. So large machines will never be as strong and agile as small ones. And every time you add another moving joint, the structure gets weaker and more flexible. Also keep in mind that the available prime movers boil down to a gasoline engine, diesel, or a turbine. So far no other power source even comes close. And last but not least, these things are expensive. And the more large precision joints and actuators you add, the spendier it gets. You end up with a large slow lumbering machine thats hard to control and easy to damage. What are you going to do with it? When you spend that kind of cash, the guy with the big checkbook wants something useful from it. In reality a trackhoe is a lot cheaper and more useful.

[C2H5OH]

1) You ain't gonna build the kind of thing you're envisioning for a measly $100K. $100M is more like the budget you're looking at needing, and that's to do it on a shoe-string with your engineers doing the R&D on a 'labor-of-love' wage scale.

2) You're going to come up with something who's only real-world use-case is as an attraction at Monster Truck rallies. No practical real-world utility to justify the expense. And probably not enough income from doing Monster Truck rallies to ever reimburse your cash outlay to build it.

ETA: I must say, though, that this particular brain-fart of yours is less incredibly stupid than your usual class of threads. With this one, you've come up with something that qualifies as "If I had Elon Musk's wealth, what could I do with it that would be more fun than overpaying for Twitter by a few billion and then crashing it's value by 72% in just over a year?" It sure as shit would have been a lot cheaper than what he wasted his money on, slowly killing Xitter.

[Archinist]

Originally Posted by Jaglavak

1)

Of course there's probably things they don't show us, it could malfunction or fail once every few minutes, and I wonder a large company with a RnD budget could iron those bugs out. After all their mech is mostly using already existing components so it's probably not perfect.

Regarding power source, I wonder what the maximum usability you'd get out of having the power source be a ceiling tether, a low endurance but high output battery, or like a shorter tether that goes to a portable generator on a trolley (or a truck next to it). If it's not using a ICE engine because it's designed for indoors use for example. People always say the limitation of "power armor" stuff is the power source, why don't we see exoskeletons that uses, say a tether going to a truck, tank or wheeled generator, which could be armored-up or have a propulsion method attached to it, like a armored-generator-cart or mini truck. Which the exoskeleton dude/dudette rides on.

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Originally Posted by C2H5OH

1) You ain't gonna build the kind of thing you're envisioning for a measly $100K. $100M is more like the budget you're looking at needing, and that's to do it on a shoe-string with your engineers doing the R&D on a 'labor-of-love' wage scale.

2) You're going to come up with something who's only real-world use-case is as an attraction at Monster Truck rallies. No practical real-world utility to justify the expense. And probably not enough income from doing Monster Truck rallies to ever reimburse your cash outlay to build it.

ETA: I must say, though, that this particular brain-fart of yours is less incredibly stupid than your usual class of threads. With this one, you've come up with something that qualifies as "If I had Elon Musk's wealth, what could I do with it that would be more fun than overpaying for Twitter by a few billion and then crashing it's value by 72% in just over a year?" It sure as shit would have been a lot cheaper than what he wasted his money on, slowly killing Xitter.

I don't know about $100M, the MegaBots/Gundamn robot went on sale for $50k after the owners realised they wouldn't get any income from it, and some Yoytube engineers/mechanics made a Aliens powerloader for the same.

I'm more interested if there's any real world use for a forklift that has two much smaller masts on both sides that operate either by lever or a fancy motion capture 'glove' like what they use to teleoperate robots in commercials. Sure it wouldn't match the lifting capacity as a larger single mast forklift, but in the video it's capable of picking up a car using both masts (okay we don't know if the engine was taken out or not) so it's definitely stronger then a person.


Giant Robot Image


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86 mechs are waaaaay too "out there" from looking at a youtube video of them. I don't understand the comments saying it's realistic. It shows 50 or 100 ton spider tanks flying/jetpacking/leaping or dodging bullets as every other Gundamn-era anime does. I'm no expert but pretty sure if a 50-ton mech built using current or near future materials fell 10 storeys it'd turn into a small scrapyard at the bottom.

[Jaglavak]

I am an expert and you're right about that part anyway.

The engine with the highest power to weight ratio is the turbine. Your most power dense method of actuation is hydraulics. With an onboard turbine or external power source, and enough money, you could definitely build a big humanoid robot. It would be slow and easily damaged, and balance and agility would be an expensive challenge.

Now what are you going to do with it that couldn't be done by a tank chassis with a couple of backhoe arms mounted to it? Which could be built in a month for a fraction of the cost, with armies of experienced operators available who could be trained up in a week.

[C2H5OH]

Originally Posted by Archinist

I don't know about $100M, the MegaBots/Gundamn robot went on sale for $50k after the owners realised they wouldn't get any income from it, and some Yoytube engineers/mechanics made a Aliens powerloader for the same.

Yeah. They made something on the cheap that would look good as a movie SFX, but none of those were actually useful in a real-world application.

Ripley fighting the Alien looked cool, but nothing actually useful for the fictional purpose could possibly be built on that kind of budget. If it's even possible at any budget point.