Loss of Signal Vbar Control EVO and V-Bar EVO Flybarless

Hello,

I have a V-Bar Control EVO with a Goblin Raw 500 equipped with a V-Bar EVO Flybarless Unit. The heli also has a Hobbying v4 Platinum 120a ESC, X-Nova Motor, X-Pert Servos for cyclic and KST Servo for Tail. This Heli was built in September 2023 with all new components including the V-Bar EVO. I flew it 4 times that year.

Last year, in August 2025, I had a crash with this heli after apparently losing signal. I really didn't have time to check out the cause at the time, but I did download the logs which are attached. After looking at the logs it looks like there are a number of warning entries that say "RC Input Packet Lost" and then ultimately a critical entry that says "RC Failsafe has been activated". This was apparently where the final loss of signal loss occurred resulting in the crash.

The log also has at least one other prior full flight where these warnings did not occur. So I am at a lost as to what may have happen, especially because this was a new build.

Please also note, that I have 7 V-Bar Neos that I've never experienced this issue. This is my only EVO and this happened in less than 10 flights.

I am concerned since I am not sure what could have caused the signal disconnect. I am leaning toward the unit itself as I have never had issues with the NEOs and I know there have been issues with the V-Bar EVO upon release requiring fixes.

Any suggestions would be helpful. Thanks.

Hello,

please have a look at the logs here in your cloud regarding this helicopter.
You will find lots of lost packest in logs with a flight time - even in 2023!

So - the problem exists a long time ago but this time there have been too many packets lost in a row which leads to failsafe of course.

Please check the belt drive pulleys for 100% electical connection to the motor plate. It is known that in most cases a seperate cable from tail gear pulley to motor plate was necessary - the tail boom and frame is not a good connection.

Also check the motor wiring for insulation problems.

In addition - enable the ESC telemetry (wire, load HW and battery app, set up all). You say you have a HW ESC - it is not in the log and also no battery log available. Has nothing to do with above - but more data are always helpful ;-)

Sidenote ... the last flights contain a service radio log for us. This looks perfect - so it must have been some glitches like above.

regards (EN) / Gruss (DE)

Rainer Vetter

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