Flymentor - Heli leans to he right.

[Ivor Hill]

[QUOTE=
Ivor Hill;2927887]With the settings back to default and stabilization switched off reset the swash as explained in the set up sticky.
After setting up about 15 personally and assisting with countless others I can assure you that it is not necessary to change any of the settings other than gain on the advance page. If the swash is leaning more when you correct that setting then the heli must have been set up with the incorrect setting applied.
That particular setting is to assist with spiecial large light weight heli's.
Even if it does not solve your problem you cannot fault find with incorrect settings applied. Go back to basic's and start again.

[Groucho_]

Originally Posted by Ivor Hill

With the settings back to default and stabilization switched off reset the swash as explained in the set up sticky.

Yes yes yes... That makes sense.

Why didn't I think of it before posting?

I HAVE read the sticky a while ago, maybe I should read it through again.

Tomorrow will redo the swash setup and report back.

Thanks Ivor.

[Groucho_]

OK... All set as per the sticky to the letter.

I removed the head and started from scratch.

Now swash seems fine - nice and level with default FM advanced settings.

Had to enter a figure of -40 for pitch to get all servos as close to 90 degrees as possible... I could have gone more, but the front servo would have been well over 90 by then. As it is i've got all three pretty close to 90.

The swash is perfectly level at mid-stick with a slight forward tilt - literally a hair's width between the swash and the leveling tool - at maximum and minimum points.

Balancer Gyro figures on my TX are 70 for position mode (it was 85 before) and 20 for balance mode.

I lowered the tail gyro sense figure to 30 and reduced the yaw rate to the minimum - 3. The default was too fast for me to handle.

Blade pitch checked and adjusted.

I'll try to fly it tomorrow - was dead calm today but I had no time :-(

[pril250]

Good the luck

[Groucho_]

Ivor, Prill - This is what happened in the test flights…

I flew four batteries - because that is all I had - for just over 30 minutes total.

First flight - This felt disastrous. On lifting off, the controls and the heli seemed very twitchy as though all expo had been removed, and though the heli did not seem to have the rightwards lean, I couldn't be sure, as it felt very unstable, and with lots of drifting. in fact, I put it down for a minute and upped the position hold gyro figure on the TX to 85 (it was 70). Still, when I lifted off, there didn't seem to be any difference in the heli's behaviour.

Second flight - This was very good. Possibly due to the FM needing a battery off/on to learn the new gyro value of 85 I had added. I could tell that the leaning problem was most definitely gone. The heli still drifted though. A bit of trim reduced drifting quite a bit though.

Third flight - This did not start off as good as the second one had ended. The trims did not seem to have been remembered by FM after the battery change. I suppose that makes sense. Am I correct in thinking that?

Fourth flight - Trims were re-centred before take off, and lift off was essentially perfect. Flight stabilisation was properly tested and seemed very good too, especially when the heli met the wind over the trees…

The one big problem I still have is that the heli will not lock its hover position.

The led in FM is a solid green - I am flying over patchy grass and hard beige-coloured earth in bright sunlight. The camera has a lock from essentially a few centimetres in the air, to probably well over the 3 meters limit. I'm just over six feet tall, and at that height, the green light is always nice and steady.

The balance mode is perfect, you can hear the head correcting with each gust of wind, with the heli keeping a nice vertical attitude throughout.

The position of the heli though, keeps drifting one way or another, almost as though the camera is deferring and giving preference to the TX trims. The drifting is not a slow drift either, which I would assume is what I should be getting, but a strong directional constant drift, which continues until i trim the other way. Then it will find another direction in which to drift…

I noticed that during the flight, trims had to be altered quite a bit. Not so much in amount, but in direction. The heli could need some left trim for the first minute or so, and then right trim for some time after that. Same with forwards and back trim. Again just a couple of clicks - four, maybe five at most.

My tail is quite steady - I have what looks like a slow-motion wag - as in a wag that takes a few seconds each cycle. I suppose that is normal. Also the yaw rate which I reduced to minimum is a bit too slow - I'll put that a bit higher.

That's about it - I'd still like to solve the position hold issue though. Is there any variable I should adjust?

Thanks :-)

[Ivor Hill]

Check that FM has been set for the direction that the gyro and camera are facing.
Increase positional gain untill the heli starts to dance ( rock side to side and fore and aft ) and then lower the gain untill it just stops dancing or just dances a little when very close to the ground.
FM should be trimmed in balance or off mode and if more than 2-3 clicks of trim are required reset the swash useing the software. FM does not like TX trim.

[Groucho_]

Thanks (again) Ivor.

Yes the setting in Helibal matches the gyro and camera direction.

I was trimming under position mode though, so maybe that's my problem right there. in fact I never switched to balance mode during testing. Just used position mode throughout.

Next flight I'll take off in balance mode, trim, and flick the switch to position mode when it's trimmed.

If that gets me closer, I'll up the position gain figure a couple of notches, and see if I get the wobble effect you mention.

Will post results as soon as I fly.

[Groucho_]

I didn't fly, but I did some more testing.

Holding the heli over a well-lit newspaper, FM had a green solid light.

Holding the heli still, so as not to disturb levelling mode, I simulated movement by moving the newspaper.

The results were as follows:

Heli moves Forward - Zero swash correction

Heli moves Right - Zero swash correction

Heli moves Backwards - Forward swash correction

Heli moves left - Rightwards swash correction

Is something not right as it seems to me? Or is this expected behaviour?

[Ivor Hill]

Never tried this so cannot say. Do not switch modes in flight untill you are 100% sure all is working correctly. You need to set the maximum gain possible that you can use without it causing problems for position mode.
If you are not sure what you are doing with your TX disconnect the blue wire and set gain useing Helibal. I always recommend this for set up and first test flights.

[Groucho_]

Originally Posted by Ivor Hill

You need to set the maximum gain possible that you can use without it causing problems for position mode.

Ivor, just to be clear, are you referring to the Balancer gain? (which I can also modify in TX) or are you referring to position sensor gain? (which has a range from 1 to 10 and is on 8 by default)

Also re my previous post, what I wanted to press is that it seems (in bench testing) that my FM unit only corrects for drift in two directions. Leftwards drift, and backwards drift.

So if the heli drifts left, it will correct. If the heli drifts back, it will correct also. If the heli drifts backwards and to the left, it will also correct. However, for any forwards or rightwards drift, the heli will not correct.

Unless my reasoning is bad, or unless there is some setting that needs to be adjusted to switch on the missing corrective measures, it would seem that the position hold mode on my unit does not function and I may have a defective FM.

The balancing part of FM, even in position hold mode worked perfectly after I followed your instructions. Indeed in strong gusts of wind, the heli remained perfectly upright.

[Ivor Hill]

I am refering to balancer gain the default value is +70. Correcting in 2 directions and not correcting in two directions has not been reported before and there are no separate adjustmants for this exept for elevator gain which would increase forward and backward movement.
It is not going to work correctly untill the gain is set as high as possible, I recomend you disconnect the blue wire and test with the default balancer gain of +70 and increase 5 at a time untill the heli starts to dance and then decrease untill the dancing just stops. Just like setting a tail gyro gain.
If that and some trimming does not work then you may well have a faulty unit.

[Groucho_]

Ivor,

I performed more bench tests as per your suggestions -

Blue wire was removed. Gyro Balance figure was altered using FM Portable controller.

Heli was immobilized - not hand-held.

A high contrast target was placed on a large clipboard and moved beneath the ccd to simulate movement.

At a default gyro figure of 70, corrective swash movement was practically inexistent. Definitely not enough to counter even the slightest of drifts.

At a gyro figure of 85, corrective swash movement was observed when the heli moved left and backwards. Conversely, no swash movement could be detected when the heli drifted forward or rightwards.

At Gyro figures of 95 and 100, corrective swash movement for heli drifting left or backwards was definitely more pronounced, while this time, for the heli drifting rightwards or forwards, an infinitesimally small corrective swash movement could be detected. Also, this latter swash movement could only be observed when the heli drifted very slowly.

At higher drifting speeds, the corrective swash angles for left and back drifting were deliberate, instant, and large, while the corrective swash angles at the same speed in right and forward drifting was either non existent or could at best be described as an inadequate slight creep.

While I estimate the maximum corrective swash angle for a leftwards or backwards drift to be about 10 degrees, that for a rightwards or forwards drift, couldn't have been more that one or two degrees.

No other variables were altered, and the same behavior was observed when the blue wire was re-connected to the RX.

[Ivor Hill]

Well maybe you have a faulty unit but I think you should stop analysing, disconnect the blue wire and test hover. It will either work or it won't. Just make sure the gain is set correctly and the heli is trimmed correctly.

[Groucho_]

A test hover is indeed next on the cards, though, truth be told, I'm not expecting any miracles...

I have another FM on the way for another heli, so when it eventually arrives, I'll be able to swap modules and see if this one is indeed defective. (Always assuming that the second unit will be fine)

Will post test hover results when done with the hover.

[Groucho_]

I only managed to test hover today. It took a while...

There wasn't any improvement on the positioning side of things though.

In fact the positioning figure of 95% made the heli quite unstable.

I put it down to 90 and to 86 and it was behaving more or less as before.

Essentially, there could be some sort of correction going on, but not enough to keep the heli motionless. Indeed not enough to keep it drifting gently either.

It's nothing like the videos I've seen of flymentor on YouTube.

I received another FM unit to put on a Trex 450, and this, in bench testing behaved identically to the first unit. So I'm inclined to think that unless by some freak coincidence I have two similarly performing bad units, the normal behavior of FM is to stabilise the model and reduce drift by a small degree.

I suppose that you get what you pay for in the end, and at less than $70 FM cannot be termed expensive. Especially when it does do quite a good balancing job.

Now I want to fix the tail. It seems to have a slow wag, more like a seek than a wag in fact. Constant but not fast. My FM tail gyro is set at 30. Should I increase it, or take it down?

[Luvmyhelis]

Groucho, I wish my vidcam worked but it died. Mine hovers extremely well in high winds and position mode barely drifts at all.
Lets put it this way, when you have the motor turned off and FM is engaged does your swash quickly tilt level even at 30 to 40 deg angles? If not you are missing something in the setup. When I first set mine up and it had little swash movement at one point it turned out to be my setup, not the FM.

[Ivor Hill]

I think there are enough video's already out there to show that it works. The posted gain setting tell me that something is very wrong. With settings so high the heli should be dancing like Micheal jackson on speed lol.
Very subtle movements are required to stop a heli drifting.
The tail slow wag, may be a mechanical problem ( tight) to slow a servo so the servo is playing catch up with the gyro ,or so slow a head speed. Try moving the ball in closer to the centre of the servo.

[Groucho_]

Luvmyhelis, my swash DOES tilt to correct - In the correct direction too.

I'm not sure about the 30 to 40 degree angles though... I never really measured that.

When hovering, FM does help. In gusts of wind I can hear the blades correcting, and the heli remaining quite upright.

I wouldn't go so far as to say that it's fully locked and balanced though. I never take my thumbs off the sticks and wave the TX about as I've seen done in youtube clips...

Yesterday for example, the heli was all over the place. One click of trim took it right, and the next corrective click trim took it left.

The sun was setting, so by the second battery, I also didn't have the CCD active anymore - Flashing green LED.

I believe you about your heli being more locked in than mine, it sounds like one of the many youtube videos I've seen... And I'd like to get mine working that way.

If I do in fact have insufficient swash movement, as you seem to have had previously, what could I do to increase that? What did you change in your setup?

I am assuming that all my cables are correctly placed, since all TX collective and cyclic functions return corresponding swash and rudder actions, and the FM corrections, small as they may be, are also in the correct directions.

[Groucho_]

Originally Posted by Ivor Hill

With settings so high the heli should be dancing like Micheal jackson on speed lol.

Ivor - The heli was very unstable in fact... I was surprised I managed to land it without it tipping over...

What would you say is the average position percentage on the setups you've seen?

Re Tail servo - I'll check where the ball is and move it accordingly. You wouldn't recommend lowering the figure of 30 on the tail gyro would you?

[Ivor Hill]

Originally Posted by Groucho_

Ivor - The heli was very unstable in fact... I was surprised I managed to land it without it tipping over...

What would you say is the average position percentage on the setups you've seen?

Re Tail servo - I'll check where the ball is and move it accordingly. You wouldn't recommend lowering the figure of 30 on the tail gyro would you?

70 is about right for a 450. Check all the setting on the advance page are still at factory preset.
Yes you can lower the tail gain more some are set as low as 10, bare in mind that 0 is in fact 25 so 10 is acually 35 and 30 is acually 55. But it's not likely to solve a slow wag problem.