700N DFC spinning on landing

[malloryn]

The heli is a 700N DFC all standard align gear ( 3GX, 2in1 ) with a TT redline 100

On landing the heli spins clockwise several times and has tipped the heli over a couple of times luckily with only broken links.
It's as if the tail puts in full right rudder as soon as it lands.

Is this normal for FBL?? My 500 with Beastx doesn't do this.
Do you have to auto land with the bigger helis with FBL?

I've had 600 FB helis before with none of this.

[Chris Boughton]

Hmm never had this with mine, sounds like an input is being made once landed, does the tail drift in flight? It can be the deadzone in the tx gimbals is quite high and not centering once released. thus the 3gx thinks its an input. if you can try upping the stick deadzone or tighten the tx stick tension. You problem doesnt sound mechanical sounds like the fbl unit or tx setup.

Hope this helps

[malloryn]

Hmm never had this with mine, sounds like an input is being made once landed, does the tail drift in flight? It can be the deadzone in the tx gimbals is quite high and not centering once released. thus the 3gx thinks its an input. if you can try upping the stick deadzone or tighten the tx stick tension. You problem doesnt sound mechanical sounds like the fbl unit or tx setup.

Hope this helps

The heli is ok in the air. The radio is ok. It's only on touchdown does it start to spin.
Too add, the collective range is set to -1 to +12deg for 5deg mid stick. This is for tuning the engine for hover and therefore I'm not 'planting' the heli on landing with -ve collective.

[coolice]

Hey.

Do you have the tail precompensation set the right way within the 3GX? By this I mean have you set the 3GX so that it knows it's mounted on the model upright label facing upwards (or inverted, if it's label side facing down).
If this is set the wrong way, then as the collective is lowered the model could swing the tail in the wrong direction to compensate for the torque changes on the models fuselage, as this feature adds in tail control to compensate for torque reation on the model with changes in collective pitch.

The above parameter can be found at the end of the tail gyro setup sequence, with the status led set to green this tells the 3GX it is label facing up, with the status led red this denotes the 3GX is mounted upside down.

Unrelated to this topic, but I would suggest loosing the 2in1 on this size of model. Reason being it's not rated high enough at 6amps continous and if your 3GX is running the new V3.1 firmware and you risk problems with your radio link due to power drops and subsequent brownouts.
Over on HF there is many fliers who have had the radio gear brownout on the bench when cycling the servos, get the model flying with flight loads on the blades and amp draw goes up.
.

[malloryn]

Yep I checked the the torque compensation and it was the wrong way. I haven't tried it yet as I need DFC links resulting from the last episode.
Also, when setting the throttle I didn't use the 0 to 100 pitch but only the throttle. Would this make a difference ie. why would the governor want to know the collective range.

The 2in1 is going. I've got LIFEs ready to go in with direct connection. I've had a couple of 'resets' on the bench under rapid stick movements. The swash dips and then returns with the redlight only on the 2in1.
I would agress the 2in1 is on the limit with V3.

[tonystevens]

personally id be setting more than -1 on your negative, a strong wind and you might struggle to get her down plus you want it a bit more planted on the deck when its spooling down.

[Chris Boughton]

personally id be setting more than -1 on your negative, a strong wind and you might struggle to get her down plus you want it a bit more planted on the deck when its spooling down.

^ Yes i argee seen this before with a 450 it was windy and they couldnt get it down!! Plus you dont want the wind tipping him over when spooling down.