Levitator 1: copter flys from the tips | Hacker News Reader

Levitator 1: copter flys from the tips

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It’s just so slow and graceful somehow.

I love it. It reminds me of the "mapleseed" machine that has just one blade, instead, and the whole vehicle rotates.

Probably it could have been easier to build if each blade had its own battery, and the flight controller would communicate with blades via radio, eliminating the commutator. Or even put a controller on each, all getting the same R/C input. Or the controller and battery rotate with the rotor, and the only bearing is on the landing gear.

The more usual method for this kind of vehicle has a rocket motor at each tip, fueled by high-purity H2O2 going through a catalytic metal sponge before the nozzle, pressurized by centripetal acceleration from a tank at the hub. But those are notoriously noisy.

With spinning batteries you have to burn energy fighting their inertia whenever the rotor speed changes.

At the hub, and at 1 RPS? Minimal.

His video on driving his inflatable car on a lake is just beautiful. I've watched it a few times, now.

https://www.youtube.com/watch?v=pMEtX0duGUg

So could you power the smaller propellers by even smaller propellers?

Propellers all the way down.

Wonder if it is capable of flight out of ground effect. The video shows a flight height above ground roughly below the rotor diameter which could mean it is still in ground effect.

Ground effect happens up to about half the wingspan, or about the length of one blade in the case of a rotorcraft. If you look at the 8:50 mark it seems to me that it's well above that (albeit not for very long). So yes, I think it's capable of free flight.

He posted a 35-minute followup:

https://www.youtube.com/watch?v=07jEAaAj1VA

Made me think about possible gravitational environment for space travel. Use solar wind to drive rotation of enormous blades, with living quarters at tips. Everything held tight with guy wires, propulsion on axis, potentially have rotational control thrusters on the blades.

Someday.

> Use solar wind to drive rotation of enormous blades, with living quarters at tips.

The sails would have to be constructed from some sort of ultra-strong unobtanium for this to work, or be so heavy that sunlight would not deliver the energy required.

Why do you need solar wind? Just use whatever engine you're using for moving this spacecraft.

Reminds me of a tip jet: https://en.wikipedia.org/wiki/Tip_jet

Reminds the creator, too, which is why at 2:38 he said "so, it's sort of a tip jet".

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