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Electrified wingsuit from BMW reaches 186MPH on first flight

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Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#181

Post by girvo »

tomc1985 wrote: post #133
lopmotr wrote: post #129

Earlier quoted context omitted.

Of course, otherwise those fancy cameras would have no market and disappear. Just like film is pretty much completely gone now, as are glass plate cameras. The truly inferior tech disappears and what's left fits some extreme niche where it surpasses the cheap consumer stuff in some way. There are things you can do with a PC that you can't with a smartphone too.

That's incredibly optimistic of you to call the PC dead. I really, really, hope (and am pretty sure) that you are wrong

I think the death of the PC won’t happen until phones and similar have the same power user capabilities as one. As long as we need a PC to build things for our phones, they’ll exist in some form.

The PC for everyday regular usage though is indeed dying. My girlfriend has an iPad Air with the keyboard case from Apple and it’s her primary computing device!

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#182

Post by girvo »

3princip wrote: post #113
JKCalhoun wrote: post #53

Earlier quoted context omitted.

Allow me my cynicism (this is HN after all): the rise of electric R/C planes and "foamies" has been a fascinating change in the model-airplane hobby but at the same time it has shown that you can practically put an electric motor + lithium cell on anything and it will "fly". So much so that I feel like the art/science of aerodynamics in modeling has fallen by the wayside. Your run of the mill quadcopter is an ideal e…

One could argue that the increase in hardware performance of computers has led to the art of software design falling by the wayside. Horribly inefficient software runs because the hardware performance hides the truth under the hood.

That in theory gives a programmer who does care about performance an edge: they can leverage the amazing performance of modern day chips in a way that the average product doesn’t, and it should mean a business advantage...

In practice it seems more complex than that — but I have experienced a softer version of that idea in practice with my own work. Performance does matter, but it isn’t the only factor.

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#183

Post by throwaway0a5e »

stjohnswarts wrote: post #166
tomc1985 wrote: post #122

Earlier quoted context omitted.

Internal combustion engines don't degrade to uselessness after three years

Are you joking? Electrical motors can go for decades before they need replacing if they're built well. Same with electronics. Contrary to HN bits don't rot, electronics fail though over time depending on robustness. Just because you don't update to the latest and greatest every couple of weeks doesn't mean anything if the device you're using is serving it's purpose well enough. I'm not sure where you're getting "3 ye…

Are you joking?

The kinds of electric motors that go for decades with just a couple pumps of grease are reserved for industrial applications because their economics doesn't make sense for consumers most of the time.

I like my cordless drills and grinder but I'm not delusional enough to compare them to industrial motors that are twice (or more, they tend to have massive cases) as heavy for the power output and live for decades. I have a 15hp motor kicking around that dwarfs a Tesla motor in every way except output. That kind of stuff is monumentally inefficient for any non-stationary use.

3yr and you're done sounds about right for consumer battery degradation in hard use. How long a battery lasts is basically a reflection of how nice you are to it in terms of charge and discharge cycles and how much reserve capacity you want to tote around.

We've got electric motors pretty much down and can build them for just about any use case but for a given longevity vs power output batteries are still pretty bulky for the output you get.

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#185

Post by pandaman »

For people wondering what is this for. BMW has just announced a new electric SUV (iNEXT) and started production on another one (iX3) so they are hyping their electric technology. In my opinion, they could do much better by just allowing their plugin hybrids to charge at the full rate of a lv2 charger.

A PHEV X5 could be the killer product with the X5 already being one of the best selling cars in its segment except it takes 6 hours to charge on a lv2 for the full 30 miles range due to the current limitation. The battery itself seems to be able to handle much higher current when it charges off the engine so it seems like an artificial limitations to prevent the PHEVs from competing with the few BEVs they struggle to move.

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#186

Post by Robotbeat »

sudosysgen wrote: post #141
Robotbeat wrote: post #12

Lithium-based batteries (and associated tech) are to the 21st century what the internal combustion engine was to the 20th century and what the steam engine was to the 19th century. There’s a ~90% chance you’re using a device powered by a lithium chemistry battery to read this right now (laptop or tablet or phone). The smartphone alone (enabled by lithium based batteries) has transformed the world. Lithium-based batte…

Isn't the efficiency of jet turbines, even microjets, wildly dependent on velocity? I don't know how you can calculate an efficiency without qualification.

I used figures from a hobby turboprop which gives mechanical power output in kilowatts (or horsepower, if you prefer) and it’s basically independent of velocity.

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#187

Post by skykooler »

dmurray wrote: post #95
Someone wrote: post #84

Earlier quoted context omitted.

For insects, hummingbirds, and quadcopters of similar size, there’s no danger in dropping from the sky. J.S. Haldane in “on being the right size”: “You can drop a mouse down a thousand-yard mine shaft; and, on arriving at the bottom it gets a slight shock and walks away, provided that the ground is fairly soft. A rat is killed, a man is broken, a horse splashes. For the resistance presented to movement by the air is…

> A rat is killed, a man is broken, a horse splashes. I had thought that cats could fall from any height safely, but that's not quite true: observational studies suggest [0] they have a 50% or 90% survival rate from terminal-velocity height onto hard surfaces, but not without injury. Still, I'd expect a rat could also "walk away". It's quite a lot smaller than a cat, though it may lack other evolutionary adaptations…

Rats lack the long legs of cats that allow them to cushion their fall, though. Cats have a ton of adaptations that each help with some aspect of landing from a fall.

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#188

Post by skykooler »

JKCalhoun wrote: post #53
Robotbeat wrote: post #12

Lithium-based batteries (and associated tech) are to the 21st century what the internal combustion engine was to the 20th century and what the steam engine was to the 19th century. There’s a ~90% chance you’re using a device powered by a lithium chemistry battery to read this right now (laptop or tablet or phone). The smartphone alone (enabled by lithium based batteries) has transformed the world. Lithium-based batte…

Allow me my cynicism (this is HN after all): the rise of electric R/C planes and "foamies" has been a fascinating change in the model-airplane hobby but at the same time it has shown that you can practically put an electric motor + lithium cell on anything and it will "fly". So much so that I feel like the art/science of aerodynamics in modeling has fallen by the wayside. Your run of the mill quadcopter is an ideal e…

This reminds me of various videos I've seen where people strap the guts of a quadcopter to various lightweight things to make them fly (the most recent being the Corridor Crew video on making a flying Nerf gun), and they just...work. (With much shorter battery life.) Of course, that's almost entirely thanks to the control electronics - that sort of active stabilization enables almost anything to fly. You couldn't do the same thing with a passively-stable R/C airplane, for example (speaking from experience).

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#189

Post by shi »

generalizations wrote: post #4

> BMW says the electric wingsuit enabled Salzmann to accelerate faster than his mates at a peak speed of 186 mph. (Normal wingsuit operators typically reach horizontal speeds around 62 mph.) Very cool; it appears to be an assist, however, without the power to actually do a takeoff.

> Normal wingsuit operators typically reach horizontal speeds around 62 mph.

Normal wingsuits can easily reach ground speeds up to 250kmh/155mph.

Source: https://ppc.paralog.net/listtracks.php?sort=Speed&record=C

Re: Electrified wingsuit from BMW reaches 186MPH on first flight

#190

Post by lillecarl »

usrusr wrote: post #160
lillecarl wrote: post #150

Earlier quoted context omitted.

If you lose power on a quad they become unstable, if you lose power on a heli you can pitch the blades slightly downwards which keeps rotation in them and level out close to the ground landing perfectly smooth. IIRC this is something you practice to get your license. Can be done with both RC helicopters and real ones.

But brushless electric motors are so much more reliable than combustion engines (internal or turbine), the comparison is not even funny. They are basically solid state devices. "Losing power" is simply not much of an error state outside of complete battery failure. And if you still want to be safe from motor failures (or from propeller failures), octocopters exist. I share the "multicopters are boring" attitude, but…

Absolutely, as long as they're operating within parameters there's no failing them. I've been running brushless systems in RC cars for the last 7 odd years. The only motor failures has been when It's been subject to extreme abuse, as in the rotor reaching 100+° (internally), going from ~55-60K RPM to 0 in fraction of a second or the rotor being forced through the bearings.

For unmanned flight i do agree on multicopters being the best option. See this[1] video for an example of a multicopter flying with disabled props.

However, as you see this flightmode isn't appropriate for human beings, humans should keep flying helis for now. The swash plate design even though more complex than a prop mounted on a shaft is still a rather simple design, litterally a bearing mounted on a 2 axis system and rods attached to rotate the blades. Multicopters with swash plates are interesting too as they can be simplified not to tilt the plate but only offset it up and down to alter pitch the same way all around the rotation. If. This exerts less force on the bearing, but considering there's still 4 of them rather than one might increse failure rate. With swash plates on multicopters we could have two motors driving one system that drives the props, and do many amazing things with computer aided controls in case of failure.

Idk why i keep on going, TL;DR: Being able to control pitch is key, multirotor or not.

I'm not really with Elon Musk on alot of things, but personal human flight is one thing where i agree with him, It's not going to happen.

[1]: https://www.youtube.com/watch?v=w2itwFJCgFQ

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