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Electrified wingsuit from BMW reaches 186MPH on first flight

robbreport.com

51–60 of 203 posts

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

#52

Earlier quoted context omitted.

Correct. Certain kinds of lithium batteries can be limited by the availability of other elements used in them, which are less abundant than Li, e.g. cobalt. There are efforts to reduce or eliminate the use of such elements.

Yup, and worth pointing out such chemistries are already common, although slightly heavier. Lithium iron phosphate, for instance, which also tends to be safer and have longer cycle life, has improved to the point that Tesla is planning on using it for low cost versions of Model 3 (and/or whatever their $25k model will be called), as is already common for electric cars there. Iron and phosphorous are very common and c…

LiFePo4 is a fantastic middle ground between Li-ion and LiPo—I made out like a bandit at the end of the Obama administration when all the green startups went belly-up; Chinese LiFePo4 cells were a dirt cheap and ubiquitous in California back then. I still use some of those cells to charge Lipo cells in the field.

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

#53

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 example of just throwing together motors + batteries + tech and getting a flying machine out of it. It feels inelegant to me because if any of those systems fails, the entire vehicle drops like the non-fliyng-thing that it is. Even helicopters auto-gyro for a period of time after engine failure and can firefly "fly" to a quick landing.

If there is a continuum running from "flying machine" (like a glider) to "rock", the "wing suit" seems laughably close to the rock end of the spectrum. Throwing electric motors at it....

To expose my hypocrisy, I'm a huge fan of the lifting body program out of Dryden Flight Research Center (now Armstrong Flight Research Center) of the 1960's.

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

#54

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…

If you are so inclined to answer, I’d live to know why lithium batteries and not some other form of battery? That is, do other elements not have the right properties? Are they too rare? Are they dangerous? You sort of answer a bit in your last paragraph. Why did it take until now to get to lithium batteries? Why way NiCad the thing before? Will lithium continue to dominate, or are there other competitive solutions ju…

Asimov promised me miniaturized nuclear batteries. Sad face.

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

#55

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…

> Your run of the mill quadcopter is an ideal example of just throwing together motors + batteries + tech and getting a flying machine out of it.

There's the old saw that airplanes fly using lift, but helicopters fly by beating the air into submission.

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

#56

Earlier quoted context omitted.

Bit of an aside, but are you saying you are flying an EDF glider?

Haven’t bothered :) Only “toy” EDF models, performance from an 8KW system revving at 60K rpm at 10S (10 lipo cells in series) swinging a 19” folding prop is on par with a mini turbine in terms of performance (0-> 180mph+ in under 2 seconds). Granted this is for 2 meter gliders, but I would expect similar efficiencies in larger scale applications (the bmw EDF is not that much larger than RC).

That's crazy. For a non-RC dude, how much thrust does that produce, and how much did it cost?

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

#57
post #27

Earlier quoted context omitted.

Sure, I just find it funny how in most cases 180MPH is fast, but that’s about the minimum speed for horizontal wingsuit flight. You really can strap a get engine to a brick and get it to fly, but you can’t stick a jet engine to a brick and get it to fly slowly. EX: F-15 landed safely with just one wing. A little cough propaganda, but still interesting: https://www.youtube.com/watch?v=M359poNjvVA .

I don't fly wingsuits, but from a bit of quick research it seems that 180 MPH is fast even for a wingsuit. The article itself mentions typical horizontal speeds of around 62 mph. The Wikipedia article on wingsuit flying says: > A typical skydiver's terminal velocity in belly to earth orientation ranges from 180 to 225 km/h (110 to 140 mph). A wingsuit can reduce these speeds dramatically. A vertical instantaneous vel…

Horizontal speed =/= level. The average wingsuit with a forward velocity component of 62mph is still dropping in altitude quite fast.

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

#58
post #46

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…

It's funny but I happen to be reading this on a desktop with an AGM (sealed lead acid in fiberglass) battery backup.

Congratulations, you are one of the less than 1 out of 10. AGM is great for stationary batteries, and has a place in vehicles but they will probably be replaced by lithium chemistry batteries in the coming decades as well as cost is coming down further.

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

#60

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…

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 the servos - the user could control the helicopter as if it were a quadcopter, and the electronics transforms those inputs with its sensors/gyros to control the helicopter appropriately.

This would seem to save costs due to fewer parts, lower weight, better battery efficiency, etc, but no-one seems to do it. I must be missing something?

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