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VBar EVO VLink High Vibration Mod

2 June, 2023 - 13:05 — admin

VBar EVO VLink and tail issues

for quite some time, we have noticed reports of issues related to VBar EVO VLink, where e.g. unwanted tail kicks occurred, up to the point where, in high-load situations, the tail can temporarily/briefly let go, until the load is eased again.

We found that this is caused by vibration in the 700-900 Hz range, at loads of 50+ Gs. Unfortunately, these loads can already be seen without much in the way of hard flying, depending on the airframe.

They can be made visible with VBar Control EVO or VBar Control Touch, using the Vibration Analysis Pro App. Causes, amongst others, can be the gear box, extremely stiff chassis and rotor head dampening, where all vibration and resonance can add up, but can not dissipate.

On a side note, for different sensor types and sensor technologies, there are different frequencies and loads to which they react most. This is why e.g. VBar NEO can perform well on one helicopter, while VBar EVO shows the aforementioned tail kicks.

VBar NEO is in general more sensitive, but their sensors act differently: they becomes less precise, will show more oscillation, but they will keep their center for longer. Drawback, then: the tail will not feel as locked in as on VBar EVO.

VBar EVO is less sensitive to vibration/resonances, it is way way more precise, but if overdriven, it will show the effects mentioned above.

During our testing, we found a quite simple way to significantly reduce the influence of such vibration and resonance, to the sensors.

So we would like to offer you some options, to get the best out of your VBar EVO VLink:

  1. if you have not experienced any issues so far, there’s nothing to do. Enjoy your flying!
  2. if you have experienced any such issues, please create a service ticket for your VBar EVO VLink at vstabi.info/devices (My Devices), and return it for a hardware upgrade.
  3. if you have not yet flown your VBar EVO VLink, if you have reservations using it, same as 2.
  4. for those of you who want to apply the fix themselves, we have prepared a short video on how to do it. You might require a new case, to replace the original one, please contact us for it.

Devices with a SN above 27001270 are already modified as stated here before delivery.

How to do the modification:

  

How to see if the modification has already been done:

 

More technical information on the topic: https://www.vstabi.info/en/node/2482