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Understanding the VBar EVO Vibration Analysis Tool

Posted by Razmo 
Understanding the VBar EVO Vibration Analysis Tool
June 12, 2024 09:50PM
Hey Guys,

I've noticed the Vibration Analysis tool options have changed. From what I understand, it used to offer the choice to select one or all three categories. Motor, Main Rotor and Tail. I'm now noticing these options no longer exist. I see a list of several different options, none of which I understand.

Can someone explain how to independently select vibration analysis for just the Motor, just the Main Rotor and/or just the Tail please? Any additional information with regard to the current list of options would be helpful as well.

Thank You,
Raz
Re: Understanding the VBar EVO Vibration Analysis Tool
June 13, 2024 10:12AM
Hi Raz,

are you referring to the standard vibration analysis tool, or to the one which comes with the Pro/Value Pack?

Kind regards

Eddi

Born to fly ...
forced to work.
Re: Understanding the VBar EVO Vibration Analysis Tool
June 13, 2024 04:23PM
Hi Eddi,

I'm referring to both. I'm familiar with the ability select between Motor, Main Rotor and Tail, which is all I've ever used, but my Evo with Pro doesn't offer these choices. It lists a handful of choices I cannot make sense of. At this point, I'm trying prepare myself to be capable of determining whether a rebuild is exhibiting vibrations at either the Motor, Main Rotor or Tail.

Thanks,
Raz
Re: Understanding the VBar EVO Vibration Analysis Tool
June 14, 2024 09:28AM
Hi,

OK ... Motor, Main- and Tail-Rotor are calculated/approximated RPM, to help you evaluate from where (which frequency) vibration originate, when you look at the graph. Looks as if that selection is only available in standard.

You can always de-/select Pro, at vstabi.info/devices, Apps, for that serial no., if you want the other screen.
Works almost everywhere, whenever your transmitter has a WiFi (personal hotspot when at the field).

Still, the basics apply: a main rotor rotating at 2,000 rpm / 60 seconds will peak at 33 Hz and change (very low frequency, very little effect but may cause wobbles), while a tail rotor rotating at 2,000 rpm * 4.5 ratio (give or take) / 60 seconds will peak at 150 Hz (these are vibrations which may cause the tail fin to become blurry, or the tail boom supports), and a motor running at say 12s * 37 V * 450 kV will peak at 333 Hz (these are vibrations which you rather feel or hear already, than see). Oh, by the way, 333 Hz sounds like a servo refresh rate ... might that interfere somehow, under adverse circumstances? Hm ...

In Pro, you can also select the sensor element you want to check (Aileron is default, it's where you see most, by experience), to compare.
You can write a graph, too, which tells you the maximum G loads and maximum overall vibration levels, throughout a flight.
And you can see the detailed live values from the accelerometers, like their orientation (-1 G pointing to the center of earth, 0 G when a sensor is on knife-edge, neither positive nor negative Gs pulling), and the noise level. If the noise level exceeds 16 Gs on a NEO, for example, the red (!) will flash, indicating that the limits of the more precise, more sensitive IMU are exceeded. For the high range sensor (less precise, more robust), this indication is not deemed necessary, because 200 Gs should be way out of range. Still, you will see high values (100+ Gs, 160 Gs were measured on a 1st gen Kraken, 204 (!) Gs are a sad record on a nitro) in the graph. If so, this should trigger your internal alarm winking smiley
Such high noise values will also show when higher vibration frequencies occur (from the gearbox, teeth clicking with multiple kW power, and only in one direction; you can easily see 2.some kHz to even higher, on multi stage gearboxes—these are frequencies you definitely hear as a whine, and they can even be trasmitted over the air, like, if a loudspeaker with sufficient sound pressure would point at such a sensor, the sensor would react the same way, even if it would not 'feel' the vibration through a physical connection). So, they are a good indicator for such, as a source.

Lastly, the log can already help: if it's full of high or extreme vibration warnings, even if you don't push the heli and it's drive system to the limits all the time, it's an indication that the overall vibration levels measured by the sensors inside the VBar are off.
This may or may not cause troubles, drift, tail kicks or sudden swash plate deflections, Rescue going the wrong way.

Please also refer to (?) as well as to this.

—Eddi

Born to fly ...
forced to work.



Edited 1 time(s). Last edit at 06/14/2024 09:28AM by Eddi E. aus G..
Re: Understanding the VBar EVO Vibration Analysis Tool
June 14, 2024 09:59PM
Hi Eddi,

Are you telling me I can deactivate pro to to use the standard Vibration options then reactivate pro without losing my pro setup parameters, like talking switches, etc.

Very honestly, I have no idea what you're describing with regard to understanding and using the Vibration Analysis Pro Features. Could there be a video somewhere that explains how it can be used with examples?

Also, a side question. Why is my AR column via parameters always greyed out even when I have motor idle activated which is used for Auto Rotation?

Thanks,
Raz
Re: Understanding the VBar EVO Vibration Analysis Tool
June 17, 2024 09:25AM
Hi Raz,

VBar App management 101:

You can dis-/enable single Apps using the Shop App, in Transmitter Settings.
This goes for all free Apps.

You can dis-/enable single Pro Apps only using the web site. In the Shop App, a QR code will point you there (use mobile device).

You don't loose anything. Even if you disable Talking Switches, the settings you made will not be lost, just the App will be disabled, so you can use the original feature (again).
Same goes for ... Vibration Analysis Pro.

I have no idea if there is a video. But honestly, grab a transmitter, a loose VBar NEO or EVO, or a (small) model w/ blades removed, and try.
Or write a graph while flying the real thing, then evaluate it, or take a screenshot and we help.

Side question: you can enable AR bank 4 in Model Setup / Model Tools / Manage Banks. Requires Pro (or Pro+Rescue).
Default is, the current bank will be used also in Motor Switch Idle position
Option is, enable a fourth bank / flight condition, e.g. if you want to adjust parameters, for autorotation.

Kind regards

Eddi

Born to fly ...
forced to work.
Re: Understanding the VBar EVO Vibration Analysis Tool
June 20, 2024 08:58PM
Hi Eddi,

Thanks for this. I was able to disable Vibration Analysis Pro, perfect. Very honestly, I didn't even know I had a Pro version of the Vibration Analysis tool that could be disabled. Correct me if I'm wrong, but in order to use the standard Vibration Analysis Tool, Pro software is necessary, correct?

I was also able to activate Mode 4 with ease, thank you.

Aside, we very much need a video illustrating how to use the Vibration Analysis Pro Features with examples. From what I've found in the net, basically zero, no one seems to understand it.

Thanks,
Raz
Re: Understanding the VBar EVO Vibration Analysis Tool
June 21, 2024 09:15AM
Hi Raz,

Pro came as a freebee for the first batch of VBar Control EVO, which had the distance issue between the main board and the loudspeaker smiling smiley

Right, the basic vibration analysis (live value, max. value) is always there, also in Express. The standard graphical display comes with Pro on the flybarless. And the extensive version is part of the Pro-/Value-Pack, for VBar Control Touch and EVO.

You're actually the first who's trying to get to the bottom of it smiling smiley
I guess if there had been more questions about it, there'd be more info, also in the hive mind, and maybe also a video or a how-to.

The standard tool is actually also questioned very rarely.

—Eddi

Born to fly ...
forced to work.
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