Drift

[Fozy]

So I am hovering today nice and close to the ground. Things are going well but I find that it wants to drift left . Is that normal to have input right stick or is that just ground effect?

[LockMD]

So I am hovering today nice and close to the ground. Things are going well but I find that it wants to drift left . Is that normal to have input right stick or is that just ground effect?


Could be ground affect that close to the ground, but when you say drift to you mean its turning or going sideways without turning. If the later, your swash is not level. Tighten your right link to the swash and loosen the left equal amounts. One turn each would be a good place to start.

[BigAl07]

It all depends on how BAD it was and how CLOSE to the ground. Ground effects can be mind boggling but honestly it's good practice to get low and learn how it reacts in "Ground Effect" because you'll always encounter it unless you merely fly into the ground rather than a controlled landing :)

Good luck and HAPPY HOVERING!

[sokal]

reason for the right stick input is to compensate for the tailrotor pushing air to creat the antitourque of the main rotor system
it called TRANSLATING TENDENCY

During hovering flight, the single rotor helicopter has a tendency to drift laterally to the left due to the lateral thrust being supplied by the tail rotor. The pilot may prevent left lateral drift of the helicopter by tilting the main rotor disk to the right. This lateral tilt results in a main rotor force to the right that compensates for the tail rotor thrust to the left.

Helicopter design usually includes one or more features which help the pilot compensate for translating tendency.
Flight control rigging may be designed so the rotor disk is tilted slightly right when the cyclic control is centered.
The collective pitch control system may be designed so that the rotor disk tilts slightly right as collective pitch is increased to hover the aircraft.
The main transmission may be mounted so that the mast is tilted slightly to the right when the helicopter fuselage is laterally level

[Fozy]

It wants to slide left, with no rotation....it occurrs as soon as I take off to about 12 to 18"

[HeliMix]

unless you merely fly into the ground rather than a controlled landing
:lol: :clappp

[carlo_the_wonder_frog]

Most helis do this, the rotor pushes you left while counteracting torque. Sokal had it right.

[Fozy]

fair enough....thanks

[SeaComms]

You can use some trim to keep it from drifting if you are never going to do inverted, but this will tilt te swash to the right slightly. Just remember that when inverted the drift will be the other way, so you will be doubling the inverted drift with the trim.

[Fozy]

LOL.....

If i'm upside down at this point of the game a little right trim will be the LEAST of my problems....

Thanks guys

[sokal]

You can use some trim to keep it from drifting if you are never going to do inverted, but this will tilt te swash to the right slightly. Just remember that when inverted the drift will be the other way, so you will be doubling the inverted drift with the trim.
so your saying TRANSLATING TENDENCY is no longer a factor when inverted

well i belive no matter wich way you flip it helicopter dynamics are always thier

even inverted the tail will still act as a prop and push you so this mean you will still need to compensate thier by hand or buy some other means

im really trying to see it and wish i could agree but the dynamics do not change
but in the helicopter world we use this phrase PFM (pure F%&%^ magic)

[Roehl]

So, how did you guys set your trim or sub-trim to compensate this lateral drift of the heli? Do you trim it or just compensate it on right stick input.

[LEADWORKS]

So, how did you guys set your trim or sub-trim to compensate this lateral drift of the heli? Do you trim it or just compensate it on right stick input.

I trim it out. No sense in fighting the chopper when hovering.

[LockMD]

So, how did you guys set your trim or sub-trim to compensate this lateral drift of the heli? Do you trim it or just compensate it on right stick input.


your talking about the left drift at takeoff only.....just apply right stick. If you trim it then you'll be constantly applying left to fight the trim while in flight.

[LEADWORKS]

The heli will still tend to drift left even after takeoff because the tail rotor blows the heli sideways to the left. If I set my swash perfectly level, it drifts left at all altitudes. There is more tendancy for it to drift left at takeoff, so don't trim it while you are in ground effect, trim it for stable hover a few feet off the ground. It only takes a couple clicks to the right for mine. Then you will still have to apply some right cyclic when taking off, but once you're airborne, you won't have to anymore.

[LockMD]

The heli will still tend to drift left even after takeoff because the tail rotor blows the heli sideways to the left. If I set my swash perfectly level, it drifts left at all altitudes. There is more tendancy for it to drift left at takeoff, so don't trim it while you are in ground effect, trim it for stable hover a few feet off the ground. It only takes a couple clicks to the right for mine. Then you will still have to apply some right cyclic when taking off, but once you're airborne, you won't have to anymore.


Maybe its me but I have NO trims or subtrims I do have a left drift at takeoff ONLY though :confused:

[eugenefelisco]

The heli will still tend to drift left even after takeoff because the tail rotor blows the heli sideways to the left. If I set my swash perfectly level, it drifts left at all altitudes. There is more tendancy for it to drift left at takeoff, so don't trim it while you are in ground effect, trim it for stable hover a few feet off the ground. It only takes a couple clicks to the right for mine. Then you will still have to apply some right cyclic when taking off, but once you're airborne, you won't have to anymore.

Get atleast 2 feet off the ground then trim it. Mine the swash is a hair tilted to the right just for hovering huh.

[LEADWORKS]

Maybe its me but I have NO trims or subtrims I do have a left drift at takeoff ONLY though :confused:

Sounds like your swash linkages are the proper length so that the swash is already at the perfect angle to cancel out the left drifting tendencies while in flight, so all that remains is the little bit of drift when in ground effect. I would imagine that's probably the best way to have it. I haven't bothered adjusting my linkages, because when I switch my batteries, the stinken servos change their center points, so I have to adjust trim in the Tx anyway. I'm still using stock servos.