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[Radio Controlled]

You're saying that as if the NPC armies can't have their own mercenaries, special ops, humanity values, or weird traditions that cause them to march up to the big black gates of the nearest UWM base they can spot and duke it out with the defenders. I try not to pigeonhole things into any specific role. I'd rather have a design that works for everyone, and then some dedicated units for special circumstances.

But even then, a ducted fan jetpack suit is still inferior to a drone in all the areas where it matters. Also, trying to have a design that works everywhere all the time isn't very efficient. Is there merit in universality and adaptability? Sure, but within reasonable limits. It's the difference between a car that's sporty but also roomy, and a vehicle that's a car but also a submarine.

My design philosophy is: the right tool for each job. If that means some universality, then it will get that, but no more than strictly needed (and some margin for error of course). When building for an army, that often means more specialized units (again depending on situation. An infantryman must be adaptable. An artillery unit not really, it just need to shoot things good) as far as I'm aware.

Mostly, yet not entirely. See above. And don't forget that the Sword's division is not the only merc group in the ARM forces, even right now.

From various discussions with syv and pw on the topic, yeah, I do think the differences are substantial.

Perfect and recent example: would a simple heat seeker missile work as AA? It should, but it's expensive when using tokens, and due to the rtd d6 system still kinda wonky, when looking at our Sword team. But for npc's, going from our own sods to rebels we supply? They ought to work really well. It's a proven system! And yet, for player characters, it'd probably not really work, compared to alternatives.

That's mostly because people tend not to waste fuel, I'd say. PW abstracts away "minor usage", and only really limits things when things reach a certain scale - like getting to orbit, or flying a long distance in one go.
Though at this rate he'll abstract away even the ammo. Let's toss ammunition concerns out the window and give everybody rapid-fire rocket launchers!

... I do think he abstracts ammo often already. When ammo usage is updated on wiki, it's usually done by ourselves anyway (or more precisely, our amazing wiki gnome team). Still, remember we should have even better fuels now thanks to my research project, so Mk.III operational range should have increased.

Well then, you don't even need Anton to do anything. Just search the VR database for generator-driven VTOL turboprop dropships of ye olden times, and you're set.

I'm just trying to explain why I think a drone design would work better than what you have in mind. If I do ever need one, you can be sure I'll let ARESTEVE design one for me. Besides, that was as an answer to your 'they should exist already' in regards to how much time it would cost to design these (as a 'new project', as you said it).

I can be as naive and deluded about its usability as I want to be, but if it works, then it gets made and tested.

*Cue Simus swooping in and noping it all to hell and back again* 

But really, aside from the engineering problems (which you have acknowledged, as far as I can see?) we're just trying to explain why we think an alternative design would work better. As I said, you are free to design electric poodles that shoot lasers out their eyes, but then if you ask for feedback (which you did, if I remember correctly?) you can expect people to point out that, no, obviously kinetic cats work better.

Worst that can happen is that it ends up being one of those rarely bought specialized suits in the armoury and that one battleship gets a crate of suits it will never use. Besides, this is a game and it's supposed to be fun. And that suit is definetly fun and plausible.
Plus, it's Sean's project, it's his character's choice to build it. That's his job. In the end his character is the one who has the final say in trying to build this.

He did ask for feedback, and he's getting our personal opinion on the matter.

As I've said before, in the end, I prefer whatever option works best. If Sean, despite my heavy a priori doubts, can make this work, then all the better! I love being proven wrong if it means we'll be better of because of it.

I still don't see what the problem is. Both suits are multipurpose and cover different areas.

For example, Sean's can easily be used underwater, a Mk3 boils everything around it. So it would be perfect for spec ops requiring you to go underwater and then escape quickly. The suit may not be able to go supersonic like the MK3 but it should be able to achieve the same speed.

Because a well designed drone can do these better still. Also, Milno used his Mk.III in the dam missions sans problems if I recall correctly. I guess you have a point for spec ops... But they already have these they could use:

Spoiler (click to show/hide)

[Nikitian]

By the way, to chime in:
What would you people say if Sean's design could be made around the price of the current Mk II or jump pack? RpTC law calls it would be much cheaper to produce than regular Mk III, so we could probably outfit entire infantry companies with those, as opposed to a few squads of elite specialist Mk III users. Would that addition to our forces make this design worth producing?

On a semi-related note, I think it's high time we reconsidered and discussed the role of infantry (all kinds of infantry) in our military doctrine, the way we did it with battlesuits.

[Sean Mirrsen]

To be honest, Sean, it's like you've got an invisible dragon in your basement.  If someone asks to see it, you say it's invisible.  If someone asks to hear it moving around, you say it's silent.  If someone asks to throw chalk dust on it to see the outline, you say it's permeable to chalk dust.  At some point there's nothing in the basement at all.  If the design of something requires so many caveats, at some point you are designing nothing at all.

Wait, so which parts of the design are impossible, exactly? Ducted fan compact jetpacks work IRL, as demonstrated by the Martin Jetpack. Electric ducted fans are efficient enough for VTOL and high-speed flight, as demonstrated by Project Zero. A personal electric VTOL has been in development by NASA for a few years, but, eh. You know how NASA is with side projects these days. This is current-day technology, which the ER-verse is supposedly centuries ahead of. Even just taking the existing technology I just mentioned, and combining it with the advanced power systems in the form of the compact generators, and the personal exosuit system used as a mounting instead of an external vehicle-like frame, this project is feasible. What else do you want?

Your invisible dragon implies that any of my claims are untrue, whereas all I'm seeing is that you're just not liking the answers I'm providing. In the end, even as one of the Council, you would have no power to overrule the creation of a prototype. I can be as naive and deluded about its usability as I want to be, but if it works, then it gets made and tested.

That's kinda missing the point, Sean.  None of the claims have to be untrue, indeed, all of them are true.  The dragon makes no noise, cannot be seen, and is intangible.

What you are designing is like a Martin Jetpack, except it doesn't have a power source, (you've left it unspecified), doesn't have an engine, (you still need something to move the power from the power source into electricity, and then into the motors), and doesn't have a fusalage or frame, as I have no idea what it's actually made of, or what is holding it together.

It doesn't have any performance characteristics, other than being capable of flying everywhere forever.  It has no operational ceiling, flies at no defined speed, is not of a defined size, has no lifting capabilities, and masses nothing.

That's what I mean by invisible dragon.  I am unable to interact with the dragon, as I am unable to interact with your proposed suit.

Wait, you... want me to provide specifics, beyond what I already said? I don't understand you there. I specified the frame used - a MkIII-like aerodynamic exoskeleton. I specified the powerplant - an ER-tech generator. I specified the propulsion - electric ducted fans. I have no idea about the specifics because I have no idea what a MkIII weighs, what kind of output to mass ratio an ER-tech generator has, what exact maximum torque an ER-tech electric brushless motor of a given size can have, what high-tensile-strength lightweight materials exist in ER to make propellers out of, I know nothing of this. That universe does not exist except in PW's head and notes.

But PW can't be expected to know all of those things either, he is not a physicist. He can approximate numbers if he is given some sort of tangible thing to compare them against. That's the purpose of the Council - scientific advisory.

So question for you, then, sir knowledgeable person. How much must a ducted fan flight-suit weigh, maximum, in order to fly with current tech? Probably not much, or not enough. Then how large and strong must its propellers and motors be to have enough lift for double the mass of a MkIII? How strong must the materials be to make them smaller? How powerful, in real-world terms, must a generator that drives those motors then be?

If you can answer those questions, then PW - who knows his universe - will be able to say if the required materials science, electric engine technology, and powerplant technology, are actually as readily available to work with as I believe they are.

If you can't, then I'm afraid all both you and me can do is point at the Martin Jetpack, at Project Zero, and at NASA's Puffin, then vaguely wave our hands around for a plausible-sounding explanation, slap a generator on the back of the thing, and call it done. From then on it's just up to PW and the council to decide on some balanced stats for the thing, such that it is fairly priced compared to its rocket-powered competition, and has reasonable flaws as befits is highly polarizing construction.

I want to have an electric ducted fan flight suit that gets 200kph in horizontal flight, can pull 2.5g along the main thrust axis, and doesn't disintegrate if it's so much as grazed by a laser rifle. I know that RL tech can't match that yet, but it has things that are close, and I think that ER-tech can bridge the gap and make it possible. Whether or not it does, is not my question to answer.
I see nothing else I can really do.

[syvarris]

Holy... I didn't check ER for most of the day, and shit went down.

Now, I've got my own opinions of course, but I'm gonna put them in the below Spoiler.  First, I'd like to ask everyone to take a breath, and wonder whether they're making other people's lives happier with what they're saying.  Honestly, the last few pages look, to me, like they're bordering on a flame war.  I'm honestly extremely surprised it got that far, since generally Tinker people are pretty civil.

Spoiler: Hopefully non-inflammatory opinions (click to show/hide)

Actually, I'm way too tired to provide a decent commentary.  I felt like I saw where the disagreements between sides were, but I forgot it halfway through the explanation.  Maybe tomorrow.

In lieu of calming commentary, have some soothing music.

Oh, one thing for the numbers explanation request: I got PW to let me power a quadcopter capable of lifting 80+ pounds using a few gauss rifle gens, which are the size of card decks.  He also, later on, let me build an automatic crystal rifle capable of destroying a battlesuit in seconds, and that rifle was cheap and had nigh-infinite ammo.  Both of those were done purely from math, RL tech, and numbers PW gave.

Anyone who acts like physical numbers are important for a Tinker project does not know how Tinker works.  If numbers are needed from PW, those numbers can be gotten- and those numbers can be whatever you want, as long as you know how to phrase the question.

[Devastator]

I want to have an electric ducted fan flight suit that gets 200kph in horizontal flight, can pull 2.5g along the main thrust axis, and doesn't disintegrate if it's so much as grazed by a laser rifle. I know that RL tech can't match that yet, but it has things that are close, and I think that ER-tech can bridge the gap and make it possible. Whether or not it does, is not my question to answer.
I see nothing else I can really do.

Thank you for naming some numbers.  Sadly, I don't see how ER tech can bridge the gap.

What you need to lift, minimum, is about thrice that of the prototype listed, about 140 kg, to lift the ERverse robot soldiers.

The Martin Jetpack can lift about one kilo per two kilos of dry weight, that is, without fuel.  I'm going to assume you can do much better than that, (despite the jetpack being made of kevlar and carbon fibre, which are both very light and very strong.)  Say one kilo per one point five kilos, including the engines and the turbines, but not including the generator.

Now let's look at it from an energy standpoint.  The Martin Jetpack has a 150kw engine.  It lifts 430 kilos upwards, with a maximum climb rate of 800 feet per minute.  That's about 4 meters/second, which implies a maximum acceleration of about 1.1g.  Useful force is about 4600 N.  That's a bit over 3% efficiency, which is actually pretty damn good for an air turbine.  Lets assume you can do twice that in the ER verse, which is well beyond iffy, but sure, lets go for it, for a 6% efficiency.

You need to lift 140kg * 2.5, or 350 kg, so far so good, and in order to get 2.5 g acceleration, you need 8580 watts.  At 6% efficiency, you need a 143kw engine.  Again, so far so good.

Now how many TPU would a 143 kw engine be?  Well, combat lasers need what, 4TPU generators.. and they're about what, 200 watts?  So you'd need.. a 715 TPU generator.  Hmm.  There's the rub. 

I'm also not mentioning that you need turbines twice the size to deliver the 8580N of upward force, not to mention it needs to be big enough to carry it's own generator.

The thing is, I'd think you could build one easy, if you just accept a large range rather than an infinite one, and that it would be about the size of a big car or small pickup truck.  Those blueradite shards would make for a nifty power source, and you could probably get a 500 km range out of it.  200kph in air is probably too high (at that point intake design and aerodynamics become non-trivial), but 100 or 150 would be pretty easy.  And it wouldn't imply that 145kw infinite energy generators are pocket-sized.

[Sean Mirrsen]

I want to have an electric ducted fan flight suit that gets 200kph in horizontal flight, can pull 2.5g along the main thrust axis, and doesn't disintegrate if it's so much as grazed by a laser rifle. I know that RL tech can't match that yet, but it has things that are close, and I think that ER-tech can bridge the gap and make it possible. Whether or not it does, is not my question to answer.
I see nothing else I can really do.

Thank you for naming some numbers.  Sadly, I don't see how ER tech can bridge the gap.

What you need to lift, minimum, is about thrice that of the prototype listed, about 140 kg, to lift the ERverse robot soldiers.

The Martin Jetpack can lift about one kilo per two kilos of dry weight, that is, without fuel.  I'm going to assume you can do much better than that, (despite the jetpack being made of kevlar and carbon fibre, which are both very light and very strong.)  Say one kilo per one point five kilos, including the engines and the turbines, but not including the generator.

Now let's look at it from an energy standpoint.  The Martin Jetpack has a 150kw engine.  It lifts 430 kilos upwards, with a maximum climb rate of 800 feet per minute.  That's about 4 meters/second, which implies a maximum acceleration of about 1.1g.  Useful force is about 4600 N.  That's a bit over 3% efficiency, which is actually pretty damn good for an air turbine.  Lets assume you can do twice that in the ER verse, which is well beyond iffy, but sure, lets go for it, for a 6% efficiency.

You need to lift 140kg * 2.5, or 350 kg, so far so good, and in order to get 2.5 g acceleration, you need 8580 watts.  At 6% efficiency, you need a 143kw engine.  Again, so far so good.

Now how many TPU would a 143 kw engine be?  Well, combat lasers need what, 4TPU generators.. and they're about what, 200 watts?  So you'd need.. a 715 TPU generator.  Hmm.  There's the rub. 

I'm also not mentioning that you need turbines twice the size to deliver the 8580N of upward force, not to mention it needs to be big enough to carry it's own generator.

The thing is, I'd think you could build one easy, if you just accept a large range rather than an infinite one, and that it would be about the size of a big car or small pickup truck.  Those blueradite shards would make for a nifty power source, and you could probably get a 500 km range out of it.  200kph in air is probably too high (at that point intake design and aerodynamics become non-trivial), but 100 or 150 would be pretty easy.  And it wouldn't imply that 145kw infinite energy generators are pocket-sized.

Okay, now that is a fair bit more constructive. ^_^

Really quite informative too, all the way up to the generator. (I'm really just assuming all numbers you gave are correct as long as they pass a sanity check - my modus operandi is verisimilitude in such things).
I don't know about how powerful combat lasers need to be, but 200 watts is less power than my ten-year-old desktop PC is using. And, if I'm reading the techinfo sticker on my laptop's charger right, about enough energy to power five portable tablets.

For reference, the typical lasers the US army uses to take out aerial drones and the like, which are probably comparable in power to a ER laser rifle on a high power setting, or a really low-power cutting laser, are in the neighborhood of 150kW. I.e. the HELLADS system, which is designed to be mounted on a Hummvee.

Let's get it scaled down to a reasonable number and say that 1 TPU is in the neighborhood of 10kW, putting the handheld laser rifle at 40kW. I don't know, so it seems more believable from a current-day standpoint. That would mean I need a 14.3 TPU generator. A 4TPU generator on the Spektr is integrated into the stock (well, more like it is the stock). Conservatively estimating the weight at... five kilograms? The whole weapon has a decent strength requirement, but it's bulky by itself as well. That means an array of 4 such generators, for 16 TPU, would weigh 20 kilograms, and assuming I don't botch the math too badly, the end power requirement with the mass increase is 151kW, or 15.1 TPU, almost comfortably under the capacity.

How far off the mark am I?

((Edit: further googling turned up Lockheed-Martin's 30kW laser that can take down a UAV with a two-second pulse, so my 40kW mark for the handheld laser rifles in ER isn't that far off. Huh.))

[Devastator]

Really quite informative too, all the way up to the generator. (I'm really just assuming all numbers you gave are correct as long as they pass a sanity check - my modus operandi is verisimilitude in such things).
I don't know about how powerful combat lasers need to be, but 200 watts is less power than my ten-year-old desktop PC is using. And, if I'm reading the techinfo sticker on my laptop's charger right, about enough energy to power five portable tablets.

For reference, the typical lasers the US army uses to take out aerial drones and the like, which are probably comparable in power to a ER laser rifle on a high power setting, or a really low-power cutting laser, are in the neighborhood of 150kW. I.e. the HELLADS system, which is designed to be mounted on a Hummvee.

Let's get it scaled down to a reasonable number and say that 1 TPU is in the neighborhood of 10kW, putting the handheld laser rifle at 40kW. I don't know, so it seems more believable from a current-day standpoint. That would mean I need a 14.3 TPU generator. A 4TPU generator on the Spektr is integrated into the stock (well, more like it is the stock). Conservatively estimating the weight at... five kilograms? The whole weapon has a decent strength requirement, but it's bulky by itself as well. That means an array of 4 such generators, for 16 TPU, would weigh 20 kilograms, and assuming I don't botch the math too badly, the end power requirement with the mass increase is 151kW, or 15.1 TPU, almost comfortably under the capacity.

How far off the mark am I?

((Edit: further googling turned up Lockheed-Martin's 30kW laser that can take down a UAV with a two-second pulse, so my 40kW mark for the handheld laser rifles in ER isn't that far off. Huh.))

(I'm a lot more constructive when I'm not trying to poke at an invisible dragon!  ;-p)


Hmm, I might have lowballed the laser power some.  Lasers do get a lot of bang for the buck, though..

Hmm, looks like Lockheed-Martin shot a drone down with a two second pulse from a 10kw laser a couple years ago as well as a 30kw laser last year.  I don't think they're measuring the lower limit.  It's also trailer-sized and IR, for what that's worth.  They're also building it to shoot down supersonic missiles and mortar rounds, which you can't do with the handheld laser rifle..  so it's less powerful than that.

I'd suppose a better way to figure it out would be to what you can't do with the laser rifles, that way, we know they're not powerful enough to do that.  Industrial cutting lasers are at about one KW... so that would probably be the upper bound.  They're not more than that, or you wouldn't need cutting lasers.  (You might need stronger lasers against military-grade armor, but it wouldn't make sense to have cutting lasers if laser rifles did it but better.)  You also could probably shoot down a drone just fine with a 1kw laser, drones are big but they're slow and very fragile.  Missile, probably not, but that's okay too.

I think I could live with that.  Overall efficiency would be better than current, which would bring it to about 40-50%, for 2-2.2kw generator power required.  Lets say two.  That would make one TPU 500 watts... good enough for ballparking purposes.

At 500 watts, that would make it a 387 TPU generator, weighing 483 kg.. which is too much.  You're probably overestimating the 5kg / 4TPU ratio, though.

To be honest, you could probably jigger the numbers around so they work, but lasers are really effective for the electricity they use.. and chemical fuels are really, really good energy stores.  It's easy enough to mock the obsolescence of fossil fuels, but a kilo of gasoline still stores a mean 42 megajoules in it.. enough to power a 10kw laser at 50% efficiency for 35 minutes.

..plus, well, I'd rather not make energy storage obsolete.  If the solution to everthing is to throw infinite energy generators at it, that kinda wrecks the fun.

..and I don't even want to think of what I would do with infinite energy generators good for 8kw/kg, available in any size.  I wouldn't mind discussing them via PM if you don't believe me.  ;-)

[Sean Mirrsen]

RL industrial cutting lasers are for cutting sheet metal, not buildings.

But, yeah, I'm probably rather too optimistic with 10kW to a TPU. Hm.

See, I'd really rather have infinite range over just "really long range", because you can get "really long range" by other means. The ducted fan flight pack has way too many limitations compared to the rocket pack to settle for anything less, that's its primary strength - effectively unlimited power supply plus all-electric propulsion system, it's the Quantum Vacuum Plasma Thruster of atmospheric flight, and (tangentially) the reason people wanted to see nuclear thermal jets work back in the day. The ability to stay in the air indefinitely, and the lack of need for resupplies, should not be discounted.

So I'd really prefer to have this particular design scheme work. It's integral to its purpose.

Rest assured though, the bluerad cells are going to be replacing a lot of generators in the upcoming designs. Such efficiency of storage does a lot to push them into "functionally unlimited" territory. I recall a bit of dialogue from the XSGCOM fanfic, about the XCOM laser rifles. The advanced batteries only hold about enough power for a thousand pulses, but if you think how much you have to be shooting to deplete that during a typical mission...

Anyways. I'd like to request a more exact quote on generator mass, and maybe even power, from PW, but in the meantime it's fair to assume that you're closer in your estimate than I was. I don't want to drop the project, so I think I'll wait for answers on that front - besides, we got research done for better generators, if I recall correctly.

Just the power output figure is pretty great help, actually. 143kW (which is lower than the actual power that's going to be needed, electric motors are not 100% efficiency themselves) is actually rather a lot. A 150kW diesel electric generator weighs in at 2.8 tons. (A 200kW one is 3.5 tons) I think PW can make provide a figure on the size and mass of the required generator from those figures. Let's continue this once we have some solid numbers to work with.

[tryrar]

You know, this reminds me of a tentative idea I had for an actual flightsuit that used small jet engines rather than rocket pods, and wings good enough to provide lift when moving. The obvious issues I saw were that unless it was an oxygen atmosphere it would be useless, and that it might be heavy enough to not really be man-portable, even with an exoskeleton. That and it might not be able to fly longer or more efficiently than a rocket pack, even with the efficient fuels we have.

[Devastator]

There's another possibility, you know.  You could give up the flying and make an infinite energy electric bycycle.  You'd probably want pedal-assistance, and it would be better for reasonably lighter characters, but you could make a bike that could go forever.  If you make it able to fold up, it would be really convienent for a lot of things.

I also didn't do the math assuming that you would need to support the generator (frame weighs more to properly support generator), or for the larger turbines required for the greater forces required for more max force  ;-)  The actual math assuming you need larger rotors for a larger thrust would have required me to break out the paper... they aren't reasurring numbers, though..  I'm not even sure it's possible if you assume the generator weighs nothing at all.

The 143kw number assumed a 6% total efficiency number... so that's already taken into account.  That's about in the range of 'ludicrous' for what the application is.  It's also a 143kw generator, not a 143 kN engine.

At the end of the day, though, I am going to have to remind you of the specifications.  You're asking for far greater overall performance than any pure rotocraft in history, intended to be wearable, rather than a vehicle, with a very large carrying capacity for it's mass and power, with infinite range, while being quiet, and (presumably) cheap.

It's also annoying me that the number for performance is listed in 'g's' for a purely atmospheric craft.  ;-)  That's a thrust-to-weight ratio, not a performance number!  And it's a huge one, like everything else!

[tryrar]

Hmm, how about something that's more piloted than worn? This sounds like it might be more in the realm of a replacement for a battlesuit flightpack, or we could make smething along the likes of a minishuttle using this: I had the idea of something that you'd half pilot, half wear using the fans you're proposing that appears similar to those minisub you see all the time, just an atmospheric equivilant.

[Devastator]

To be honest, if you remove the VTOL capabilities, and requirement to stay up forever a powered flight suit shouldn't cause any problems.  You would have the difficulty of taking off, but if you jump off a shuttle or something that'll do it.  Same with something you strap onto rather than wear;  Military gliders and such have existed forever, and adding some power to something like that would work fine.  You'd probably not want to fight or walk around while strapped to it, though.

[tryrar]

heh, I just found the most awesome thing while tooling around the internet, the Magneto Hydrodynamic Explosive Munition(
DARPA link). Basically, it uses am EM flux capacitor and pinching to form penetrators rather than chemical explosives, and is supposed to be much more efficient than the latter at it. With the new radite batteries, I'm thinking I can get this into the size of a gauss round!

[Sean Mirrsen]

2.5g is a fairly large ratio for an atmospheric craft, I agree.

However I'd like the rotorcraft to at least be able to carry another person, so as to be used for rescues. And to have a power reserve in case one fan is blown off/up/out, so as to leave the pilot (sans passengers or extra weight) a sliver of a chance to approach the ground in a nonlethal manner in that situation. Unlike the Martin Jetpack, this contraption would have two additional fans on a long lever arm (or rather leg - down at the ankles), allowing to compensate the torque from the shorter lever arm of a single stronger lifting fan, and prevent an uncontrollable spinout and crash. In theory, of course.

Sometimes you really confuse me though.

The actual math assuming you need larger rotors for a larger thrust would have required me to break out the paper... they aren't reasurring numbers, though..  I'm not even sure it's possible if you assume the generator weighs nothing at all.

You do realize that all-electric ducted fan vehicles already exist, right? The "Project Zero" technology demonstrator I linked to the wiki page of, running on regular rechargeable batteries. I'm really confused as to what you mean by it being impossible, especially since you mention larger rotors. Can you explain?

It's also a 143kw generator, not a 143 kN engine.

Yeah I know, and I do mean a diesel generator rated for 150kW of electric output. I literally just went and searched for diesel generators for sale online.

At the end of the day, though, I am going to have to remind you of the specifications.  You're asking for far greater overall performance than any pure rotocraft in history, intended to be wearable, rather than a vehicle, with a very large carrying capacity for it's mass and power, with infinite range, while being quiet, and (presumably) cheap.

Not quiet. Not by a long shot. It's quieter than the thundering rockets of a MkIII, but still nowhere near "quiet". The "wearable" part is... pretty much a given, considering. We got exoskeletons and power armor to mount things on. The carrying capacity I want to be at most its own weight, which is... hm. Actually about on par with the Skycrane. Yeah, that part is probably too much.
In regards to performance though, I'm just looking to pack the Project Zero into a man-portable package. That thing is downright impressive, and in their presentation they outright said that the only thing that's holding them back from actually going beyond a "technology demonstrator" article is the lack of high energy density power storage.

It's also annoying me that the number for performance is listed in 'g's' for a purely atmospheric craft.  ;-)  That's a thrust-to-weight ratio, not a performance number!  And it's a huge one, like everything else!

Heh, alright, alright.


So. Okay, so 2.5 is a stupidly high TWR to expect of a non-toy ducted fan craft. Let's drop it to say... 1.5. That should be closer to feasible, and if an overcharge system is added (or just a generator over the rated maximum), may even allow rescue ops. How do the numbers look then?

[Devastator]

For the record, a thrust ratio equivalent to 2.5g is nearly three times that of a fuel-less SR-71 blackbird.

I think I got confused there, and I must have made a mistake juggling numbers in my head, and forgot the larger concept.  Of course you can build one with a sufficiently energy-dense power source.  I suppose the question is if it can be called 'wearable'.  You should be able to do better than that concept craft, though, ER batteries are a lot better than real batteries.

Hmm, those are some pretty damn big rotors on that experimental craft.

Unfortunately, there's a real dearth of specs available.  I can't even say how big the rotors are, much less how much thrust it generates, or how much power is stored, or what it's weight capacity is.  It's also far too big to really be called wearable.

TBH, in order to lift another person you'd need it to lift about another 60kg.  If you're a bit short, you're left with a vehicle that relatively slowly drops to earth, and that's workable.  That would require a max thrust of about 12N/kg, which should be doable, and beaten only by really exotic rotorcraft using things like RoR.  It would also result in a very usable climb rate of several thousand feet per second, which is more than perfectly functional, and probably a top speed between 100km/h and 200km/h

I'll do the math a bit later.  I'm getting a bit burned out on this today, and have other stuff to do right now.  Okay?  I'm also going to need to do the math on comparing ER batteries and such to normal chemical energy, and that'll make my head hurt.

Off the cuff, it looks doable, but I can't say how big it needs to be without doing the math.