10 ms·

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

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.

usrusr 6y ago
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.
- carlhjerpe 6y ago
  Absolutely, as long as they're operating within parameters there's no failing them. I've been running brushless systems in RC cars for the last 7 odd years. The only motor failures has been when It's been subject to extreme abuse, as in the rotor reaching 100+° (internally), going from ~55-60K RPM to 0 in fraction of a second or the rotor being forced through the bearings. For unmanned flight i do agree on multicopters being the best option. See this[1] video for an example of a multicopter flying with disabled props. However, as you see this flightmode isn't appropriate for human beings, humans should keep flying helis for now. The swash plate design even though more complex than a prop mounted on a shaft is still a rather simple design, litterally a bearing mounted on a 2 axis system and rods attached to rotate the blades. Multicopters with swash plates are interesting too as they can be simplified not to tilt the plate but only offset it up and down to alter pitch the same way all around the rotation. If. This exerts less force on the bearing, but considering there's still 4 of them rather than one might increse failure rate. With swash plates on multicopters we could have two motors driving one system that drives the props, and do many amazing things with computer aided controls in case of failure. Idk why i keep on going, TL;DR: Being able to control pitch is key, multirotor or not. I'm not really with Elon Musk on alot of things, but personal human flight is one thing where i agree with him, It's not going to happen. [1]: https://www.youtube.com/watch?v=w2itwFJCgFQ https://www.youtube.com/watch?v=w2itwFJCgFQ
  - usrusr 6y ago
    Well, simple propeller pitch control is a lot easier than a swash plate because it's idle when the pitch is kept the same and it's no problem if making it slower simplifies it. A swash plate is active on each rotation and needs to be fast enough to work the blade through a certain range of pitch values within have a rotation interval.

usrusr 6y ago

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.

carlhjerpe 6y ago
Absolutely, as long as they're operating within parameters there's no failing them. I've been running brushless systems in RC cars for the last 7 odd years. The only motor failures has been when It's been subject to extreme abuse, as in the rotor reaching 100+° (internally), going from ~55-60K RPM to 0 in fraction of a second or the rotor being forced through the bearings. For unmanned flight i do agree on multicopters being the best option. See this[1] video for an example of a multicopter flying with disabled props. However, as you see this flightmode isn't appropriate for human beings, humans should keep flying helis for now. The swash plate design even though more complex than a prop mounted on a shaft is still a rather simple design, litterally a bearing mounted on a 2 axis system and rods attached to rotate the blades. Multicopters with swash plates are interesting too as they can be simplified not to tilt the plate but only offset it up and down to alter pitch the same way all around the rotation. If. This exerts less force on the bearing, but considering there's still 4 of them rather than one might increse failure rate. With swash plates on multicopters we could have two motors driving one system that drives the props, and do many amazing things with computer aided controls in case of failure. Idk why i keep on going, TL;DR: Being able to control pitch is key, multirotor or not. I'm not really with Elon Musk on alot of things, but personal human flight is one thing where i agree with him, It's not going to happen. [1]: https://www.youtube.com/watch?v=w2itwFJCgFQ https://www.youtube.com/watch?v=w2itwFJCgFQ
- usrusr 6y ago
  Well, simple propeller pitch control is a lot easier than a swash plate because it's idle when the pitch is kept the same and it's no problem if making it slower simplifies it. A swash plate is active on each rotation and needs to be fast enough to work the blade through a certain range of pitch values within have a rotation interval.