YC's latest moonshot bet is a startup building a $380K “flying motorcycle”

Post by tyingq » Fri, Mar 08, 2019, 12:59 PM UTC

Animats wrote: post #153

Where are they getting the engine? You can get model aircraft jet engines with enough power for this.[1] Various human-carrying craft have been built that way, such as the Zapata Flyboard.[2] But the engines have a lifespan measured in hours and not enough reliability for carrying humans. That's why all the demo videos of these things are over water, or tethered. People have been trying to build small, cheap jet engi…

Post by darkpuma » Fri, Mar 08, 2019, 1:09 PM UTC

dalbasal wrote: post #207

dmurray wrote: post #193

Earlier quoted context omitted.

Agreed, this seems like a huge problem and this > The startup’s most pertinent problem is creating the autonomous stabilization technologies that will make flying the Speeder effortless and safe. looks like a smokescreen for marketing to the tech crowd. Everyone is going to believe they can solve the stabilisation problem: that's "just software" and we see demos of robots solving stabilisation problems all the time.…

If that "most pertinent problem" is tech savvy investor/journalist bait... it's genius. I read that and thought "well that's probably solveable." OTOH... In the context of a moonshot, maybe the non-existence of an affordable & appropriate engine is ok. Tesla started with an unaffordable battery, and built a really expensive car with it. The car was good though, compared to other cars in the sheiks & princes price ran…

Post by darkpuma » Fri, Mar 08, 2019, 1:15 PM UTC

mannykannot wrote: post #220

Animats wrote: post #153

Where are they getting the engine? You can get model aircraft jet engines with enough power for this.[1] Various human-carrying craft have been built that way, such as the Zapata Flyboard.[2] But the engines have a lifespan measured in hours and not enough reliability for carrying humans. That's why all the demo videos of these things are over water, or tethered. People have been trying to build small, cheap jet engi…

The sound, I think, is coming from a large headset like the ones prominently worn by the ground crew. I don't think it's the pilot's headset, as it does diminish a bit at the greatest range, and I would expect some radio talk between the pilot and the crew. I suspect they are noise-canceling headsets, as there is something about how it sounds that reminds me of vacuuming with a noise-canceling headset on. Small has b…

Post by darkpuma » Fri, Mar 08, 2019, 1:19 PM UTC

rplnt wrote: post #211

mpweiher wrote: post #201

Earlier quoted context omitted.

> [small jet engines, price, piston engines for GA] Another important reason is fuel consumption. Jet engines in general are extremely thirsty, AFAIK the only reason they became (unexpectedly!) competitive with piston engines is that they allow the planes to fly so much higher where the air is thinner. In addition, small turbines are even less efficient than big ones.

And all GA jet engines now are turbofans with high bypass ratios. Not something you can do at small scale. Would have guessed the relative speed they operate at also plays a role. And wouldn't this require quick changes in thrust? Not sure that heavy big diameter fans could do that.

Post by nicoburns » Fri, Mar 08, 2019, 1:23 PM UTC

estsauver wrote: post #208

nicoburns wrote: post #205

Earlier quoted context omitted.

It seems to me that if you want to do this right, you ought ot be thinking about how you can bootstrap the infrastructure and industry to produce the neccesary products and agricultural inputs locally. Also, can you make it sustainable. AFAIK, industrial farming is destroying soil quality in nations that use it, and some farmers are looking at returning back to techniques like crop rotation...

The good news is our farmers are way too poor to put too much fertilizer/inputs into their fields, they're generally applying fertilizer with a spoon seed by seed. To be honest, we're not going to tell farmers that they should pay 4x more to produce their inputs locally. These are some of the poorest people in the world, telling them they should continue to have a hunger season every year because of long term concern…