CCW pirouette`s

hello,

I have some trouble`s with my 450X helikopter for about 2 months and i don`t get to the solution, so i thought i drop a question here..

With CCW pirouette`s my helikopter start shaking in the pirouette so hard that i got to get it out of the pirouette. it`s an Elevator shake. With low speed pirouette`s i see it also happen, but with less intention. With full speed its getting very heavy and i cant pirouette no more. And the strange thing is that Cw pirouette`s are as flat as it can be, no problems there...
I have re-build the tail, changed spindle shafts, changed gears, main shafts, other blades, do the reset again, changed gains ( reduced or increased tail and main gain.. but with no luck..

Maybe somebody got some idea`s where to look for??

My setup is:

3 savox 0264mg on cyclic and an nexxspor servo on the tail. The esc is an 35A castle talon. and a vbar neo.. with the vbar governor. And the vbar controller...

I have the setup file included of my 450x. ( a .vbr file)


Regards,
Mark Bekker
The Netherlands

Hi Mark,

can you please attach the setup file (didn't make it or so it seems).

If possible, also provide a short video (upload somewhere and link here).

The elevator shake, I take it it's nose up/down like the maneuvers some pilots do on purpose?

Kind regards

Eddi

Born to fly ...
forced to work.

Hello Eddi,

Thank you for your reply!

Ik hope now i have included the setup file in the right way as a .zip.

Yes the nose goes heavily up and down with the speed of the pirouette.... I`ll try to shoot a video this day. It`s very difficult to explain. So thank you for the tip! i`ll do my best to shoot it today..

Regards Mark Bekker

Hi again,

you seem to have very low gyro gains (main rotor and tail rotor), even for a 40 size. Is this necessary?

Then, what strikes me as odd: no trims on the swash plate, and although the trim flight time-bar is all green, no trim values either.
Either you are the most accomplished modeler, achieving the perfect setup without any trim necessary, or there's something off which the gyros have to compensate for all the time.
This could mean, in stress situations like piros in the more demanding direction, the VBar can no longer compensate for properly, especially with the low gyro gains e.g. in Bank 1.

But it's also always possible that the model comes into a resonance under certain load conditions, and e.g. the rotor head dampening plays tricks.

Is it the same at different head speeds, or does it change with different head speeds?

Kind regards

Eddi

Born to fly ...
forced to work.



Edited 1 time(s). Last edit at 07/04/2019 11:49AM by Eddi E. aus G..

hi Eddi,

bank 1 is the one that has been setup to really fly, bank 2 and 3 i need to finish the setups, but the rpm`s i have already dialed in.

I try to have a mechanical setup that is really spot on. so withe the travel of the swash. i try to work with the holes on the servo horns to change the travel untill it travels the same way in all the 3 position`s ( low, mid and high stick). and than if it drift left i`ll compensate this with de length of the swah rods coming from the servo`s..

i`ll set it up again this mid-day and i`ll try to shoot the video, including my new setup file with the new value`s..

maybe i`ll try some new dampenerers.. maybe that ì`ll do the trick

thanx again for the help Eddi, i appriciate this very much.. You will hear me i think end off the day.

Regards, Mark Bekker

hello,


Here the link of my video. I noticed today some elevator wobble when i am in a hover.. Needs a little bit more tuning... But you can see the shake in the video:

https://youtu.be/1-H0wfyjOCw

regards Mark Bekker

Hi Mark,

holy sh*t! I was expecting something but not that!!

Let's talk about the helicopter again, and about the setup.

How's the VBar mounted, what type and direction of swash plate do we have, how's the rotor head linked?
If possible, attach a couple of clear (!) pics.

If for some reason e.g. the CH2 and CH3 servos were plugged in criss-cross, and the functionality of the inputs and sensor reactions was somehow tweaked to work anyway by reversing here and there, this could possibly result in such things, especially on a small and agile helicopter.

Was this from the beginning, did you do the setup from scratch (create new setup), was the VBar working properly earlier on, maybe on a different model, was there any mishap involved in the meantime, anything changed?

Best,

Eddi

Born to fly ...
forced to work.

Hi eddi,

Mark here again..

New setup file is included! Double checked if i had some wrong wiring like you said, but that`s not the case. Been flying for 30min and it`s betteR just a little wobble… Been playing with the gains of the rotorhead and the Tailgain, compensation, also some headspeeds. It`s performing better with this setup. It`s almost gone.. still a small shake with CCW piro`s...

There is soms friction i think in the tail. Don`t get it locked in. its very restless.. A bounce witch stops etc.... Performed a tail optamalization en B side is way off.... So gonna check that tomorrow.. MAybe there could be a little bit more tail comensation, but first getting the tail to work as it should…


Never had such issue`s with past setups.. I`m changing the setup part now. Fast tight turns to check the tail gain, and no tail slide for checking that..

Photo`s coming tomorrow of the unit..

Thanks!
Mark

hi eddi,

As asked, here the photo`s of the unit..

I think the problem is the Main gain.. Todag i have raised ageen the maingain and it`s getting fading away. Not yet complete, but the rest is i think a bit swash leveling...

When i have time tomorow i will shoot a video how it pirouette`s now...

Regards, MArk

Hi Mark,

OK, keep me posted, I'm curious.

Kind regards

Eddi

Born to fly ...
forced to work.

Hi eddi,

You will here me. At the moment bad wheather here..

Funny enough i din't knew yet the relation between main gain and pirouettes with the vbar.. An example in the sense of learning with trial and error.

Regards Mark