How do you know when your heli is setup correctly?

[chrisleematt21]

Maybe an odd question but how do you know when everything is setup properly? I have a 550 with a vx1n on and I thought it was setup correctly but it used to drift backwards I just thought it was meant to so I lived with it, but I was taking to somebody who said it shouldn't be drifting at all as it is flybarless.

I put up with the drifting as I thought i was being to fussy by trying to correct it as everything appeared to be setup correctly.

What im asking is there a test which you can do which shows that its all setup is ok, is it supposed to beable to hover hands off?

How do you know?

[waveydavey]

Not if you've got wind pushing it backwards. This hands off hover thing is misleading, yes the heli will be reluctant to move if the unit has no input, same as a well setup flybarred machine. If it's moving backwards make sure your swash is level, make sure your cog is good, make sure you have absolutely no trim anywhere, that sort of thing.

With no wind and a good mechanical, balanced setup the heli may hover hands off but don't use it as a yardstick. Instead, does it fly well, does it feel connected, are the roll/flip rates comfortable for you. Overall, are you comfortable flying it, if the answer is yes then it's a good setup

[p4ddy]

I'd try levelling your swash again. It sounds like it's off enough for it not to level out correctly & to trim properly. I think I'm correct? stick a flybar back on it & i'll answer your questions

[Gavalar]

Use the trim flight on your vortex. It will tell you how far out the swash level is. There are videos on how to do this.

[gazmk2]

Hovering hands off is not really possible without some sort of GPS hold mode etc, all helis will want to lean to one side or the other due to the tail rotors opposing the torque reaction from the main rotors. This will make it drift a little, less so with a flybarless but it still happens a bit.

Like as has been said above, does it feel nice on the sticks, is it stable in a hover and does it flip/roll how you want it to?

[chrisleematt21]

As i said i think it flys nice apart from a bit of backwards drift but i thought that was normal as helis arent that stable. I have done a trim flight and the results were 0.24l and 0.1b which seemed odd as it drifts back. Does the trim flight affect all flight or just piros?

[tomatwalden]

Left drift is normal, but backwards just means either the swash isn't level or the CoG is aft of the main shaft. As others have said, "hands off hovering" isn't something you're going to get ...

[chrisleematt21]

Thanks guys thats answered my question

[Grumpy]

Left drift is normal,

I disagree.. i dont think you should see any consistent left or back drift on a properly setup heli. Helis might not be stable as in automatically 'self-righting', but even so it you put them in a perfect hover on a calm day they should pretty much stay in the orientation and position you put them 'hands off'. Sure after several seconds they will start to gradually drift, but the drift direction should be random. If it's drifting in the same direction consistently then that indicates something not quite right.

Dont believe me?... here's my 7HV videos earlier today (flying with a 'cheapo' Kbar):

[pgkevet]

I'm confused. To my logic a good fbl system should self-correct and hold whatever tx input is given? If so it should then try to hold despite cog or even 'dodgy setup'. The biggest variables ought to be due to tx gimbals and servo slop and those tiny variations is on-board currents etc. As in if you have a bckward cog then to achieve a stable hover you have to have heli sl nose-down to counter it..and fbl should hold that if you go hands free.
I accept that on my align helis there's always some slop on links and swash and on my 600's rjx head on it's swash driver arms. That and I dont suppose for a moment the align servos hold a digital position with perfection.

[Grumpy]

I'm confused. To my logic a good fbl system should self-correct and hold whatever tx input is given? If so it should then try to hold despite cog or even 'dodgy setup'.

You are correct, the FBL will 'try' to hold the attitude of the heli but if the CG is way off or swash out then despite the FBL's efforts it will gradually start to drift away from the set attitude.

[tomatwalden]

Well, a FBL heli or a flybarred heli is neutrally stable. That is, it should resist external forces such as wind and limit their effect. But they are not self correcting ... If your hover is only slightly off, over time the heli will drift. Self levelling is a available with some FBL units, but it limits the agility of the heli.

[SaneAdam]

Maybe an odd question but how do you know when everything is setup properly? I have a 550 with a vx1n on and I thought it was setup correctly but it used to drift backwards I just thought it was meant to so I lived with it, but I was taking to somebody who said it shouldn't be drifting at all as it is flybarless.

I put up with the drifting as I thought i was being to fussy by trying to correct it as everything appeared to be setup correctly.

What im asking is there a test which you can do which shows that its all setup is ok, is it supposed to beable to hover hands off?

How do you know?

As has been said, a level swash and correct CoG are crucial to a heli set up. There are ways to get round slight discrepancies by using the fbl to tune it. But imo, its best to spend the time finding the perfect Cog. Swash levelling with tools is quick and easy… even doing it by eye is fairly quick and reliable providing you have something you know is accurate for visual reference. So that shouldn't be a problem

Finding the perfect CoG is not always as easy, as it is often a case of experimenting with component placement and battery positioning. Some helicopter designs make it very simple if there is ample room on the battery trays to move the packs back and forth. Because the packs are so heavy… they are the best thing to help fine tune overall balance. It is obviously more difficult with designs that aren't as flexible when fine tuning battery placement.

I personally would always go this route… I just think it is best to give the Fbl system a nice stable accurate platform to work from. Get everything as accurate as possible mechanically