Heli shivers in hard moves.

[Pitch-Itch]

Hey guys, I've gotten most of the bounce worked out of my goblin 500 but I've ran into something else that I'd like to work out. Very recently I've progressed a lot and am now flying smack mixed with big air/smooth 3d.

I've noticed that when I smack the heli is shivering. I don't know if it has always done this, or if this is something I am only now seeing because I am flying low and close.

Take for example a simple back flip, but pop and lock style. When the heli is at the transitional phases (vertical with little to zero pitch) the heli is doing what I can only call a shiver. It is fairly high frequency and not very violent, but it's definitely there.

I'm not sure what parameters I should be looking at to make this go away, so I figured I'd ask. I can post up my settings if that will help.

Thanks!

[danyl]

Overall gains to high. If only in one axis, you can adjust aileron or elevator gains separately. There is also an "elevator filter" setting, but use this sparingly. It mutes the overall control of the elevator and if too high, will make the elevator feel sluggish and mushy.

[crash at 42]

Originally Posted by DavisBladeWorks

Hey guys, I've gotten most of the bounce worked out of my goblin 500 but I've ran into something else that I'd like to work out. Very recently I've progressed a lot and am now flying smack

Thanks!

Please post a vid

[Pitch-Itch]

Originally Posted by crash at 42

Please post a vid

Are you trying to help me, or critique my flying? Seems to be the latter just by what you quoted...

[Pitch-Itch]

Originally Posted by danyl

Overall gains to high. If only in one axis, you can adjust aileron or elevator gains separately. There is also an "elevator filter" setting, but use this sparingly. It mutes the overall control of the elevator and if too high, will make the elevator feel sluggish and mushy.

I'll try that. I have the head gain at 60, but I dropped the ail and ele gains to 15 and 13 respectively.

I'm already at 6 on the ele filter, so I guess my only choice is to drop overall head gain.......which I really don't want to do.

[crash at 42]

Originally Posted by DavisBladeWorks

Are you trying to help me, or critique my flying? Seems to be the latter just by what you quoted...

A picture (or in this case a vid) is worth a thousand words.
Also post your settings

[crash at 42]

https://www.helifreak.com/showthread.php?t=682481
Also check out thread above, not a 500 relates to a 380 but talks about lowering head gain to 50 so you may need to start lowering your overall head gain
How many flights on the heli, possibly dampners

[popokatepetl]

If you do some hard maneuver and see some head shiver I suggest to lower the head gain down to let's say 45% and watch the difference. If that helps I recommend to lower the aileron and elevator gain by two points each and tune the head gain in flight again.

The head gain doesn't have to be high. It just have to be high enough so the helicopter works and feel predictible in the air and locked in. I normaly end up with head gains around 50% on pretty much any size.

Video would be great. Nobody wants to look how good pilot you are but you try to describe something you see but it doesn't mean we can follow what you try to say. We see = we know

[Pitch-Itch]

Yeah I plan on getting some video as soon as I can fly. I can only fly on the weekends thanks to work. May get a chance to get a couple flights in this afternoon if the weather will cooperate.

[LoveToFly1]

Originally Posted by danyl

Overall gains to high. If only in one axis, you can adjust aileron or elevator gains separately. There is also an "elevator filter" setting, but use this sparingly. It mutes the overall control of the elevator and if too high, will make the elevator feel sluggish and mushy.

this is a little incorrect. the elevator filter does not affect the overall control of the elevator axis, it is used to tune out the elevator bounce on stops. some of my hellis need a value of 2, some need a value of 8, they feel no different other than the bounce being smaller. you are thinking of the individual elevator gain, that one will make your elevator feel mushy, but the filter will not.

[danyl]

Originally Posted by LoveToFly1

this is a little incorrect. the elevator filter does not affect the overall control of the elevator axis, it is used to tune out the elevator bounce on stops.

Okay, so I dumbed that down a little. Just for further info. I write PID algorithms. The filter does control the bounce, just as you indicated. Unlike the P (proportional) equation, the I (integral) and D (derivative) portions take the previous event into account. This is the "area under the curve". When the bounce (oscillation) begins, the I and the D values work to reduce the ping-pong behavior and taper it back to a baseline. (somewhat known as regression to a mean) Each bounce gets smaller and smaller as the PID loop applies less and less corrective value. I suspect the "Filter" changes the D portion of the equation. If you raise the "Filter" value, the equation will work even harder (taking larger steps) to return the system to a steady-state.

The I and D equations are ALWAYS in action. The system has no means of determining if the helicopter is bouncing, or just coming to a stop. Therefore the "Filter" parameter is always active, even though you may not notice its effect except under certain circumstances.