Ace4
Heliman
Location: Atlanta, GA
| If you want it to hover with hands off control, you are going to need some active control mechanism on both pitch and roll axes. If you are only going to hover, you may be able to get away with fast response tilt sensors, but more than likely you are going to need a gyro on each axis. For $20 that Telebee gyro sounds interesting, I don't know anything about it, though, like how it drifts,etc. I know Analog Devices has 2 new gyros out (or will be out any day), they're supposed to be $33 each and have temperature sensing circuitry onboard the gyro unit already. I think you really should shy away from tilt-rotors, unless you have a thorough understanding of dynamics & control systems, or can learn really fast. You're going to need to be able to come up with and implement a controller anyway to maintain pitch and roll while hovering, however it will be much easier if you don't have your rotors tilting.
You can check out this hovering experiment. The company makes control system experiments for universities, and that one has some documentation about controlling the 4 rotor hovering machine, however theirs is fixed to the stand so it doesn't actually fly. It also can use rotary encoders since its fixed. They may have some more papers online related to some of the other experiments, you can probably get some info from them too. Heck you could even email them asking if they would be willing to provide any info about propeller thrust etc.
As for thrust, just go out and get an electric motor, an adjustable power supply, a couple of different props, and a postal scale, and you can set it up so you can measure static thrust (lift in your case) vs power required for each prop and figure out which is most efficient for your purposes. Efficiency is key for small electric VTOLs, since you don't want battery weight to kill you.
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