Logo 200 - Insufficient negative pitch

Hello,

I just bought a used Logo 200, which I'm having an issue when attempting inverted flight. It seems that it does not produce sufficient negative pitch to stay airborne - even with full negative collective, it (rapidly) loses height (and eventually crash) when trying to enter inverted hover.

The collective curves seems to be set symmetrically (ranging from -98 to +96). On the ground, with the rotor not spinning, it also seems to have a symmetrical pitch range. I'm flying at a low headspeed (3500 rpm) in bank 1. Lightness is at 25 and collective balance is at 45 (not sure if these settings matter).

Are there any settings beyond the collective curve that could cause this behaviour?

edit - forgot to mention that I have the Neo Pro + Rescue enabled



Edited 1 time(s). Last edit at 09/10/2021 07:33PM by ventle.

Could you please add a full event log from a regarding flight here?

Also - holding the heli upside down - does the rescue info panel notice (z Axis) it is upside down?

regards (EN) / Gruss (DE)

Rainer Vetter

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Hi, Here's two logfiles where the flights ended in an inverted crash whil giving full negative collective. Doesn't seem to be anything out of the ordinary.

The Rescue panel correctly identifies if the heli is upright (z = 99) or inverted (z = -99).

I checked the collective range inside the collective endpoints setup panel. It is slightly on the positive side, ranging from -10.6 to +11.4 degrees, but this should still be plenty to keep flying, no? Couldn't find the correct pitch range in the manual to verify if this was correctly set up.

VBar Start -- LOGO 200 -- 10.09.2021 -- 18:33:38
18:33:38 v Reset Reason: Power On
18:33:39 i Bank 1 Loaded
18:33:39 i Bank 2 Loaded
18:33:39 v Motorswitch Motor Off
18:33:39 v Motorswitch Idle Bailout
18:33:42 i Calibration Finished
Vbar Logfile End -- 10.09.2021 -- 18:35:41

VBar Start -- LOGO 200 -- 10.09.2021 -- 18:40:19
18:40:19 v Reset Reason: Power On
18:40:20 i Bank 1 Loaded
18:40:20 i Bank 2 Loaded
18:40:20 v Motorswitch Motor Off
18:40:21 v Motorswitch Idle Bailout
18:40:23 i Calibration Finished
VBar Logfile End -- 10.09.2021 -- 18:40:57

Actually, when comparing to an older log file, it almost seems that the actual flying portion of each event has not been logged. Here's a log file from a few days ago, where I only flew upright circles:

VBar Start -- LOGO 200 -- 05.09.2021 -- 14:45:26
14:45:27;1;Reset Reason: Power On
14:45:27;2;Bank 1 Loaded
14:45:28;2;Bank 2 Loaded
14:45:28;1;Motorswitch Motor Off
14:45:28;1;Motorswitch Idle Bailout
14:45:30;2;Calibration Finished
14:46:28;1;Motorswitch Idle Bailout
14:46:31;2;Governor Active
14:46:31;1;Motorswitch Motor On
14:46:34;2;Governor is at Low Throttle Limit
14:46:36;2;Governor is at Low Throttle Limit
14:46:36;2;Governor is at Low Throttle Limit
14:46:36;2;Governor is at Low Throttle Limit
14:46:36;2;Governor is at Low Throttle Limit
14:46:41;3;High Vibration Level
14:46:51;2;Raised Vibration Level
14:47:02;4;Extreme Vibration Level
14:47:02;2;Governor Idle
14:47:02;1;Motorswitch Idle Bailout
14:47:03;2;Governor Stop
14:47:03;1;Motorswitch Motor Off
14:47:12;4;Extreme Vibration Level
14:47:18;1;Motorswitch Idle Bailout
14:47:18;2;Governor Active
14:47:19;1;Motorswitch Motor On
14:47:21;2;Governor is at Low Throttle Limit
14:47:22;3;High Vibration Level
14:47:32;2;Raised Vibration Level
14:47:42;2;Raised Vibration Level
14:47:52;2;Raised Vibration Level
14:48:02;2;Raised Vibration Level
14:48:13;2;Raised Vibration Level
14:48:23;2;Raised Vibration Level
14:48:33;2;Raised Vibration Level
14:48:43;2;Raised Vibration Level
14:48:53;3;High Vibration Level
14:49:03;2;Raised Vibration Level
14:49:13;2;Raised Vibration Level
14:49:23;2;Raised Vibration Level
14:49:34;3;High Vibration Level
14:49:44;2;Raised Vibration Level
14:49:54;2;Raised Vibration Level
14:50:04;2;Raised Vibration Level
14:50:14;2;Raised Vibration Level
14:50:24;2;Raised Vibration Level
14:50:34;2;Raised Vibration Level
14:50:45;2;Raised Vibration Level
14:50:55;4;Extreme Vibration Level
14:51:05;2;Raised Vibration Level
14:51:15;2;Raised Vibration Level
14:51:25;2;Raised Vibration Level
14:51:35;2;Raised Vibration Level
14:51:45;2;Raised Vibration Level
14:51:55;2;Raised Vibration Level
14:52:06;2;Raised Vibration Level
14:52:16;2;Raised Vibration Level
14:52:26;2;Raised Vibration Level
14:52:36;4;Extreme Vibration Level
14:52:46;2;Raised Vibration Level
14:52:56;2;Raised Vibration Level
14:53:06;2;Raised Vibration Level
14:53:17;2;Raised Vibration Level
14:53:19;2;Governor Idle
14:53:19;1;Motorswitch Idle Bailout
14:53:20;4;Aileron Sensor Value out of Range
14:53:20;4;Aileron Sensor Value out of Range
14:53:22;2;Governor Stop
14:53:22;1;Motorswitch Motor Off
14:53:27;4;Extreme Vibration Level
VBar Logfile End -- 05.09.2021 -- 14:53:32

Hi,

w/o Lightness, collective is WYSIWYG ... what you see is what you get.
Lightness shifts the collective range a bit up or down, depending to the model's flight attitude, and adjusts collective even dynamically, using the sensors.

Inverted shouldn't make a difference (and doesn't, by my own experience, the most easy and comfortable to flip micro I have ever flown).

The collective angles sound plausible, LOGO 200 uses little collective, compared.
And you always have to bear Lightness in mind, because of the range shift.

What exactly happens if you go inverted? Does the head speed drop, does it feel like you have no authority on collective?
How's it in other maneuvers, tic tocs, aileron rolls, at the top of a loop if you wanted to stop there, or elevator-like up/down, on the spot (mind that the tail could blow if you overdo that)?

Can you please try and depress one swash plate link at a time, then move collective, and see if the servo counters your pressure all the time, or if it / one of them budges, at a certain position?

Kind regards

Eddi

Born to fly ...
forced to work.

Thanks for the info, Eddi.

After getting new servo horns (they broke when it landed inverted), I now tried going inverted in bank 2 (4800 rpm), which worked well with no problems. I believe that rules out any mechanical issue?

I haven't tried repeating the issue I had in bank 1, but the headspeed stayed the same, it just lost height (rapidly) even though the collective stick was all the way down.

It would be really helpful if the factory default settings for the Logo 200 were listed in the manual or any other easy to find place on vstabi.info. Below are my current setup, I believe that only the lightness and headspeed are changed from default, but I cannot know since I bought it used. Can you help me confirm?

Banks                  1  /     2  /     3

Mainrotor
Expo                  50  /    40  /    30
Style                100  /    85  /    74
Rate ++               90  /   105  /   114
Gain                  10  /     9  /     8
Lightness             12  /     5  /     5

Swash Expert
Elev. Prec.            8  /     8  /     8
Paddle Sim.            0  /     0  /     0
Heli Size                      15
Integral              60  /    60  /    60
Pitch Pump             0  /     0  /     0
Cyclic Ring                    85
Optimizer             45  /    52  /    57

Collective Curve
Max                   96  /    99  /    99
P 50%                 48  /    49  /    49
Center                 0  /     0  /     0
P -50%               -49  /   -50  /   -50
Min                  -98  /  -100  /  -100
Collective Balance    45  /    45  /    45

Tailrotor
Expo                  50  /    40  /    30
Rate ++               90  /   110  /   130
Tail Gain             80  /    90  /   100

Tail Optimize
TC Coll.              50  /    50  /    50
TC Cycl.              20  /    20  /    20
Zero Col.                      15
Side A                35  /    24  /    10
Side B                34  /    30  /    34
Wag Supp.             -1  /    -1  /    -1

Tail Expert
Accel.                         35
P Gain                90  /   100  /   110
I Gain                70  /    75  /    80
I Limit              Off  /   Off  /   Off
Stop Gain A            0  /     0  /     0
Stop Gain B          100  /   100  /   100
D Gain               100  /   100  /   100 
I Discharge          Off  /   Off  /   Off

Governor
Headspeed           3500  /  4800  /  6320
Gov. Gain             15  /    12  /    10
Autorotation                  10%

Gov Expert
Coll. add             10  /    10  /    10
Cycl. add              7  /     7  /     7
Coll. dyn              0  /     0  /     0
Basic Thro.           50  /    50  /    70
P lim -               20  /    20  /    20
Integ.                10  /    10  /    10
P lim +               20  /    20  /    20

Nevermind, I just tried bank 1 once more, at 3800 rpm this time, and it does fly inverted, it just looses a lot of height during the transition, due to my poor collective management. I guess "insufficient collective management" is a better topic title.

Still would love to find the factory default settings in here somewhere, though! Other than that, I really love this little bird

Hi,

OK, I don't mind happens to the best of us (which I'm not ...).

Anecdote: I was perfectly able to flip and fly inverted with normal size helicopters, then ventured to micros again (some years back).
At the first attempt flipping the M120D01 (Mini VBar, VBar Governor, 2s conversion, loads of power and head speed, everything working fine) I crashed it ... I had not anticipated that I would need to be way more aggressive on collective, give it a push up before, and support it hard inverted.

With the 200 today, I could pro-flip it on the first flight, as if it was any other heli ...

I'm afraid I have no listing of the parameters either. If in doubt, I would save what's on the model, then create a new LOGO 200 setup, that's exactly what we do when we prep and test/trim fly them, before we pack and ship.

Cheers

Eddi

Born to fly ...
forced to work.