Gossky RS7 extreme vibrations?

Hello, guys,

We are having an interesting situation here.

We have three goosky rs7 with vbar Evo installed.

All three helis show extreme (extreme!) vibration level on head speeds above 2100 RPM.

The vibration level is so high that the peak goes off the chart on all transmitters (three Vbar Control Touch/Evo).

Finally, the vibration analyzer shows a huge peak at 5100 RPM. What could that be, please?

Thanks.



3 mal bearbeitet. Zuletzt am 16.07.2024 06:25 von RV.

Huhhh ... next time they do screenshots with a shotgun ;-(

One hint ... there is a screenshot app where you can assign a switch and then later download the image in best quality from our cloud ;-)


About the peak - how are things geared in this heli? Is there anything rotating with this RPM? How are the main/tail gear ratios, also if 2 stages - both stages?

5000 and above 2100 ... could be a blade thing. Is it still there running w/o blades?

On other brands we had some peaks which could have been also not assigned to a RPM - but at the end it was a gear problem of production tolerances at the teeth ... hard to track down.

Do you own the Pro Value Pack for the VBC? - If yes, use the extended analysis there and take some screenshots of the all 3 axis (gyro and low range accelerometers) to be posted.

regards (EN) / Gruss (DE)

Rainer Vetter

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1 mal bearbeitet. Zuletzt am 16.07.2024 06:25 von RV.

Thanks a lot.
The heli is:
on the ground;
with main rotor;
w/o main blade;
with tail blades.
The vibration is also there when the heli is flying.
The way this vibration at 5100rpm is now, is it safe to fly the heli?
Could this extreme vibration cause vbar to loose control? Could the heli crash?
Thanks again.



1 mal bearbeitet. Zuletzt am 16.07.2024 14:19 von ReadyToFly.

- how is it w/o ANY blades? Screenshot?
- if still there - swop 2 motor wires or program ESC running backwards. Then take another screenshot please. If it is gone then - it comes from the tail drive (which ist not running here). If not gone - main drive or head.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

Für Posts und Antworten bitte einen PC und eine richtige Taststaur benutzen sowie alle Fragen vollständig abarbeiten. Nehmt Euch Zeit, beantwortet Rückfragen in Ruhe und vollständig.
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Ok, but the way this vibration at 5100rpm is now, is it safe to fly the heli?
Could this extreme vibration cause vbar to loose control? Could the helicopter crash?
Thanks.

I am sorry - i can't answer your questions because i have never seen your heli on my bench.
It is up to the pilot to say "i feel safe to fly".

In general this level should be safe - but as we don't know where it comes from it could be a harmonic of some other stuff we don't see with the given data. To narrow it down i have asked you a couple of questions - still unanswered.

regards (EN) / Gruss (DE)

Rainer Vetter

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Posting and answering - please use a PC and a standard keyboard. Answer all questions fully, take the needed time, don't forget probably requested attachments.

Für Posts und Antworten bitte einen PC und eine richtige Taststaur benutzen sowie alle Fragen vollständig abarbeiten. Nehmt Euch Zeit, beantwortet Rückfragen in Ruhe und vollständig.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Für Einzelkommunikation bitte ausschließlich Email verwenden! - PN, Messenger, Chat usw. werden nicht bearbeitet.
For single user communication please send a email only! PM, Messenger, Chat etc. won't be read.

I couldn't test without any blades yet, but inverted the motor wires and tested it: absolutely no vibration at all. Definitely the vibration doesn't come from the motor or main rotor.

Goosky has a flawed design as to the place where vbar must be installed. The pad for vbar isn't a continuous solid cf plate. It has triangular cuts. so, in the best hipothesis, vbar bottom is only 50 per cent in contact with the cf plate. I will fix it somehow and run another test. It, only, could be the cause for such high vibration, correct?



1 mal bearbeitet. Zuletzt am 17.07.2024 01:20 von ReadyToFly.

Absolutely correct. It may be a self resonant frequency of the mount, or parts nearby.

Manufacturers shall understand, that a good position for sensors and electronics is a crucial design kriteria, but thats not your fault.

so long ... Uli
http://www.vstabi.de