Well that looks like fun (gas-powered manned multicopter)

Den onsdag den 16. november 2016 kl. 00.32.00 UTC+1 skrev snipped-for-privacy@gmail.com:

I'm guessing like quadcopters, "cyclic" by varying speed of some of engines, "collective" by varying speed of all engines, yaw by controlling the speed ratio of rotors rotating in opposite direction

How is the maximum angle (where if you tip beyond this angle, the thing would fall out of the sky {and likely kill the pilot with the still-rotating props}) typically determined?

Thanks,

Michael

with that death trap probably by killing a few pilots ;)

or more likely not trying to find out

On electric quad copters it's max angle vs. altitude, and when you're high enough the maximum is 180 degrees -- assuming you're not software limited.

On gas-powered stuff you'd also have to worry about fuel and oiling systems working inverted.

Basically, how fast can you flip it over, how far does it fall when you're doing so, how fast a downward speed do you build up, and then finally how much altitude do you eat up getting to zero vertical velocity?

Probably has speed governors on the engines, and a quad-copter controller talking to the governors.

Pitch control with the engine speed held to a constant RPM is better, but more complicated.

"You Bet Your Life" - I'm pretty sure Groucho would have had plenty to say about that suicide machine...

John :-#)#

Looks noisy, smelly, expensive, and dangerous to me.

Flying things are dangerous. Unshrouded props make it worse.

so long as the rotors are spining the device experiences acceleration in the apropriate direction and the liquids will behave apropriately. (ignoring turbulance, drag, and other wind effects)

Yes, but don't do sustained inverted flight. There was a period in time in WWII when the BF109 had fuel injection and the Allied planes had carburettors. The Allied planes would lose power after even the briefest of negative-G maneuvers. This gave the BF109 pilots an easy escape maneuver if they got into trouble: they could just push the stick down and get away, while the Spitfire or Mustang pilot would have to take the time to do a split-S.

I've seen movies of another work in progress that uses one big engine (I think it's just one) with belt drives to four adjustable-pitch props. Overall I suspect that the reliability will be a wash, and the performance better. Figure out how to drive one shaft with two motors, or make it an octo-copter with two independent systems*, and the reliability will probably increase.

• As long as it'll still fly on just one motor.

Imperial Tie Fighters have carburetors too--they all do that.

Cheers

Phil Hobbs

X-wing fighters to, no?

I think I've seen some of the more advanced quadcopters they play with a t universities use variable pitch because it is faster reacting and can even fly upside down

belt drive from one motor has the problem that you need two of the props to rotate in the opposite direction

-Lasse

Probably, I forget. Haven't watched a commercial movie in decades.

Cheers

Phil Hobbs

True. That's what gearboxes are there for, though.

A flat belt, or one that's toothed inside and out, would allow you to do it fairly easily with the right idlers. Wrap the inside around rotors A and C, and wrap the outside around rotors B and D. Break the belt and you die, though.

The old Hughes 300 (two seat helicopter) had a piston engine driving the transmission with eight belts in parallel. You could fly with five good ones.

I remember following "a chopper is born" on Discovery, where a veterinarian turned TV presenter build a 2 seater helicopter from a kit

the tail rotor is driven by number of average looking belts in series

I this covers it

-Lasse

True, but batteries only hold a charge for a few years and are expensive.

This guy built an R/C plane from a 2-stroke weed eater. Now that's inspiration!

Michael

The more modern Robinson R22 also uses belts. Not sure how many, though.

It could also do an emergency landing with zero belts.

I wonder if the quad can.