Living with 2.4
|John Cole||17/11/2008 19:21:00|
|615 forum posts|
PV's letter in All Write describes control problems with an electric plane which he had converted to Futaba 2.4 GHz. His post-crash investigation showed (as I read it) aileron controls being moved (to the left) when the motor was run full-power. He emphasises the need for power-on checks before flying, and I support that fully. He also makes some comments about aerial siting.
However, I can't understand what he describes: as least not with a correctly-working set. If the signal is correctly decoded by the Rx then the flying controls (such as aileron) will not be affected when the motor runs flat-out. If the signal is not correctly decoded then the Rx should go into fail-safe; the flying controls will freeze in their last good position and the motor should go to the fail-safe setting: 20% of full power is the default, but for electric models I set it to (essentially) Zero - by using the throttle-cut button during set-up.
So why is he seeing what he describes? Is it anything to do with 2.4 at all? Maybe it's a duff servo affected by vibration? Maybe the voltage from his BEC is dropping at full motor power and this is causing strange results (but why on just one channel?). Maybe he's inadvertently programmed-in throttle-aileron mixing (well it's worth asking!). What problems have others found?
His comments on (Rx) aerial: the Futaba recommendations are a sound way of ensuring that at least one of the two aerials can "see" the Tx but I've found the system tolerant of proximity to ESC, battery wires. motor wires and minor bits of metal. Certainly I would not expect ANY of those to create a problem during the take-off run when the plane is close to the Tx. What have others found?
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