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Jetson One – Personal Electric Aerial Vehicle

jetsonaero.com

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Re: Jetson One – Personal Electric Aerial Vehicle

#221

Post by tweedledee »

tweedledee wrote: post #55
dtgriscom wrote: post #38

Earlier quoted context omitted.

The comment was "quadcopters don’t scale up too well"; you're explaining the reverse.

They are explaining how quadcopters don't scale very well. You may be misunderstanding the explanation. The surface area covered by the rotor is much less for quadcopters and it is difficult to make up for that. Plus small rotors are less efficient. One upside for quadcopters is simplicity but that advantage diminishes with scale.

For completeness I should add; Quadrotor configurations rely on varying prop speeds to control pitch, yaw, and roll. The larger the props the more difficult it is to vary the prop speed in a timely manner. Electric motors are more weight efficient at high speeds but larger props need to be slower. You could add a gearbox but either way you are gaining weight and complexity. Plus parts start to get really expensive as you scale up and get out of hobbyists range.

Re: Jetson One – Personal Electric Aerial Vehicle

#222

Post by tweedledee »

mrfusion wrote: post #216
Toutouxc wrote: post #209

Earlier quoted context omitted.

No, because the pre-spinning (torque applied to rotor) part happens on the ground with the rotor blades set to low/no pitch. The rotor then starts freewheeling (no torque applied or transferred from the rotor) and the blades' pitch angle is increased, which slows the rotor down, but momentarily creates enough lift to lift the autogyro into the air, where it immediately transitions to forward flight.

I always assumed the main benefit of an auto gyro was a fixed pitch main propeller for the simplicity and cost benefits. I guess if you could attach the vehicle to the ground and spin up the propellor and then release you could get the same effect. Or another option is if the rear propeller could turn its rudder against the spin direction.

It’s still simpler and cheaper. The swashplate is much simpler. Much less power is fed to the main rotor as inertia is built up slowly and only for take off. The lower standard of reliability as worst that happens is you don’t take off. Engines are pushing a more forgiving higher speed prop, so engines and fuel are cheaper.

I don’t know how marginal jumpstarts are, possibly very, which would limit the utility. Especially where there is a runway nearby.

Re: Jetson One – Personal Electric Aerial Vehicle

#223

Post by IshKebab »

NovemberWhiskey wrote: post #215
VLM wrote: post #202

Earlier quoted context omitted.

> Parachutes have a minimum altitude. If you have the money, zero/zero ballistic parachutes have been a reliable thing for more than half a century. For ultralight sized aircraft, they cost about 1/5 the cost of a new airframe. Generally they don't provide much survivability IMHO. Most ultralight deaths seem to boil down to CFIT and similar "happened too fast too close to ground" incidents with a side dish of refusal…

> If you have the money, zero/zero ballistic parachutes have been a reliable thing for more than half a century. That's called an ejection seat, right? As in a rocket-propelled vehicle to launch you sufficiently high out of your aircraft to allow your parachute safely to deploy (i.e. about a hundred meters, as described in the prior post)

No, it's a parachute that is deployed via a small explosion so it doesn't rely on falling through air to open.

Re: Jetson One – Personal Electric Aerial Vehicle

#225

Post by spookthesunset »

kelvin0 wrote: post #224

So, the drone footage used to capture this video makes me wonder: - Is the camera drone VERY fast? - Or is the Jetson slow? - Is this realtime footage or accelerated somehow?

The answer for FPV footage is almost always that it is real time. FPV camera drones can go upwards of 100mph. In the hands of a skilled pilot they are incredibly agile.

They are also almost entirely built by the pilot. The entire FPV scene is a pretty cool hobby to get into.

Re: Jetson One – Personal Electric Aerial Vehicle

#226

Post by spookthesunset »

tweedledee wrote: post #221
tweedledee wrote: post #55

Earlier quoted context omitted.

They are explaining how quadcopters don't scale very well. You may be misunderstanding the explanation. The surface area covered by the rotor is much less for quadcopters and it is difficult to make up for that. Plus small rotors are less efficient. One upside for quadcopters is simplicity but that advantage diminishes with scale.

For completeness I should add; Quadrotor configurations rely on varying prop speeds to control pitch, yaw, and roll. The larger the props the more difficult it is to vary the prop speed in a timely manner. Electric motors are more weight efficient at high speeds but larger props need to be slower. You could add a gearbox but either way you are gaining weight and complexity. Plus parts start to get really expensive as…

And to put an even finer point on it, it isn’t just control authority but keeping the damn thing even stable. The only reason those things stay aloft is the controller senses minute changes to the orientation (called attitude) of the craft and adjusts the motor speeds in tiny amounts to fight those changes. Without that quick feedback loop the craft would flop all around and crash.

It’s one of the reasons you don’t see gas powered quads. Gas engines just cannot react fast enough and precise enough to correct subtle changes in attitude.

Re: Jetson One – Personal Electric Aerial Vehicle

#227

Post by NovemberWhiskey »

IshKebab wrote: post #223
NovemberWhiskey wrote: post #215

Earlier quoted context omitted.

> If you have the money, zero/zero ballistic parachutes have been a reliable thing for more than half a century. That's called an ejection seat, right? As in a rocket-propelled vehicle to launch you sufficiently high out of your aircraft to allow your parachute safely to deploy (i.e. about a hundred meters, as described in the prior post)

No, it's a parachute that is deployed via a small explosion so it doesn't rely on falling through air to open.

Can you provide a link to such a system? I did a best-efforts search and failed to turn up anything.

Re: Jetson One – Personal Electric Aerial Vehicle

#228

Post by Toutouxc »

mrfusion wrote: post #214
Toutouxc wrote: post #209

Earlier quoted context omitted.

No, because the pre-spinning (torque applied to rotor) part happens on the ground with the rotor blades set to low/no pitch. The rotor then starts freewheeling (no torque applied or transferred from the rotor) and the blades' pitch angle is increased, which slows the rotor down, but momentarily creates enough lift to lift the autogyro into the air, where it immediately transitions to forward flight.

Wow neat approach. I’m always surprised auto gyros aren’t more popular. They seem so versatile.

They also have some extremely dangerous flight characteristics.[0] To be fair, helicopters are even worse, but they require extensive training and are known to be dangerous.

[0] https://youtu.be/CfjBzrSDrV0

Re: Jetson One – Personal Electric Aerial Vehicle

#229

Post by brianwawok »

NovemberWhiskey wrote: post #227
IshKebab wrote: post #223

Earlier quoted context omitted.

No, it's a parachute that is deployed via a small explosion so it doesn't rely on falling through air to open.

Can you provide a link to such a system? I did a best-efforts search and failed to turn up anything.

https://en.wikipedia.org/wiki/Ballistic_parachute

Re: Jetson One – Personal Electric Aerial Vehicle

#230

Post by gorgoiler »

CryptoPunk wrote: post #189
gorgoiler wrote: post #170

Very cool, especially the demo video which eventually loaded. Something on their website smells a little whiffy and bovine though: ”[our mission] is to change the way we travel and make the skies available for everyone” Erm. Everyone? I don’t think so. Your mission is to give the 0.1% yet another way to be jerks, only this time with added noise!

Knee-jerk ascription of new product classes to elitism isn't constructive. The iPhone, when first released in 2007, cost $500, or about $800 today after adjusting for inflation, but launched a smartphone industry that today produces devices that are affordable enough that 3 billion own one, including some that go for as little as $50 and have better performance than the original iPhone.

Dude, it’s a helicopter.
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