Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Electrified wingsuit from BMW reaches 186MPH on first flight

robbreport.com

Post reply on HN
Print view View original

151–160 of 203 posts

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

#151

Post by base698 »

bjornedstrom wrote: post #131
base698 wrote: post #128

Earlier quoted context omitted.

It's more active jumpers over their jumping career than just people who try it once. It varies wildly jumper to jumper based on the types of jumps done (cliffs are more deadly than bridges) and how often. Most people jump for a period of 3-6 years and quit. My wife and I were pretty active jumping in the era of wingsuit videos on YouTube. In her first year we had one good friend die and 9 people we'd met or hung out…

Didn't expect to find one here at Hacker News. 698... so you must have started around the early 00:s or thereabouts? Unfortunately I share your same statistics: I was very active in the early 2010:s and in that period I lost about 10 friends/acquaintances. Since then even more people I've hung out with are gone. So yeah: wingsuiting is dangerous. But BASE itself can be done "reasonably" safely I think: personally I w…

Yeah 2000 was first BASE jump. There are a few on here. Brendan W and a few others pop up on these threads.

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

#152

Post by lovemenot »

JohnJamesRambo wrote: post #93
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…

>after another few decades of battery chemistry improvement How do you know we aren't near the end of what is possible with batteries already? I assume that people in the steam and internal combustion era thought things would just keep improving forever as well.

>> I assume that people in the steam and internal combustion era thought things would just keep improving forever

Maybe at the beginning of steam, but as early as 1824 Carnot had put a theoretical limit on it.

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

#153

Post by andrewflnr »

DFHippie wrote: post #91
HPsquared wrote: post #71

Earlier quoted context omitted.

It's a matter of scaling laws. You don't see insects or hummingbirds gliding anywhere, small things fly differently.

Butterflies do glide sometimes.

Dragonflies, too. But it's true that they can only do so for short distances. I don't think I've seen either glide for longer than a meter.

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

#154

Post by wombatmobile »

CrazyCatDog wrote: post #14

An electric ducted fan (EDF) is highly inefficient, had they put similar wattage through a gearbox to say a folding prop, efficiency may have doubled (albeit an admittedly more onerous form factor). This is just the beginning of electric assist single passenger flight! Reference: plenty of experience pushing 8KW+ through 2KG RC gliders (F5B) and far slower EDF models.

> had they put similar wattage through a gearbox to say a folding prop, efficiency may have doubled (albeit an admittedly more onerous form factor)

They chose not to do this because the more onerous form factor results in amputation of the pilot's viscera and legs.

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

#156

Post by jiofih »

joosters wrote: post #60
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…

I don't understand the lasting appeal of quadcopters in particular. We can build remote-controlled 'normal' helicopters that have fantastic performance and much greater efficiency (no need for 4x the motors and stubby blades). The only downside I understand is that R/C helicopters are very difficult to fly, but that should be straightforward to overcome by putting a basic computer + sensors between the controller and…

Fantastic performance as in? Quadcopters routinely reach 60km/h, and cheap racing models can go over 100km/h. I doubt any kind of heli will ever perform like that

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

#157

Post by hwillis »

MiguelHudnandez wrote: post #104
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.

15kW should be enough to easily lift an adult human, but the stability implications are a good reason this is an assisted wingsuit and not a jetpack. Another thing to consider is that saying it has 15kW motors and 5 minutes of thrust does not necessarily mean 5 minutes at 15Kw. That would work out to 1.2kWH weighing what I guess to be about 40 pounds in batteries alone. I'm really impressed by wingsuits, and strappin…

> That would work out to 1.2kWH weighing what I guess to be about 40 pounds in batteries alone.

Absolutely not. Sony VTC4s are early 2010s cells that do 30 amps continuous with 2000 mAh capacity[1]. 172 cells weigh in at 17 lbs, 1.2 kWh, and a whopping 16.5 kW continuous rated output.

For lower power applications, higher-capacity cells like the NCR18650G[2] weigh below 10 lbs per kWh.

[1]: https://cdn.shopify.com/s/files/1/0674/3651/files/Sony_VTC4....

[2]: https://www.imrbatteries.com/content/panasonic_ncr18650g.pdf

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

#158

Post by hwillis »

skizm wrote: post #82

I'm genuinely wondering when I can buy a personal, commercially available, vehicle that will let me fly (or maybe sail) over the Hudson river on my commute into NYC. What are the stoppers for something like this? Landing? Economics? Regulation? I'd pay more money than a car for something like this.

a pilots license

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

#159

Post by hwillis »

demarq wrote: post #24

Something seems suspect here. There is just no way that small unit could generate near enough thrust to make a real difference. I think we need to look deeper into this claim

https://www.youtube.com/watch?v=mxJJ17HV1yU

Fans that small put out enough force to literally push you straight up. Jetcat has an engine 23 cm wide which can pull 110 kg. For the same size an electric fan passes much more air.

https://www.jetcat.de/en/productdetails/produkte/jetcat/prod...

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

#160

Post by usrusr »

lillecarl wrote: post #150
palijer wrote: post #67

Earlier quoted context omitted.

Having 4 weaker motors is generally safer than one big one if something were to hit it, and you can shorten the blades because the lift is spread across 4x as many blades. Multiple motors is good as well for any motor failures, as quads (if they're well designed) can fly after even multiple motor failures.

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 they are boring for a reason.
Post reply on HN