Settings for bigger 3D bird?

[Thoemse]

I just maidenend my new Kingtech KT-800.
It swings 800mm Align Blades and has a weight of 7.4kg wet.

I am using a spirit Pro and went for the Logo 800XX settings to start out with.

I am having a wobble on the main disk when spooling up/down and mid flight too - especially with lower RPM.

Cyclic gain was at 60 first - I went down to 50 but is that still too high or should I look at different settings?

[ZeXx86]

Hello,

you might check if Geometry 6° parameter is configured correctly.
If it is too high, it can introduce oscillations.
You can easily go down with Cyclic Gain to 25% without a risk. But generally 50% should work everywhere with a normal setups.

[Thoemse]

Hello,

you might check if Geometry 6° parameter is configured correctly.
If it is too high, it can introduce oscillations.
You can easily go down with Cyclic Gain to 25% without a risk. But generally 50% should work everywhere with a normal setups.

Thank you. Yeah maybe I went a bit overboard with the Geometry parameter. I'll give it a go.

[Thoemse]

Hello,

you might check if Geometry 6° parameter is configured correctly.
If it is too high, it can introduce oscillations.
You can easily go down with Cyclic Gain to 25% without a risk. But generally 50% should work everywhere with a normal setups.

Thanks. That did it. I think I tuned the geometry when going through the wizard stages with my digital pitch gauge.

When I went back into settings today the value was showing 8° though!
I reduced it to 6° and went flying. I had a very slight wobble while spooling up but nothing I haven't seen with other big birds. Once the headspeed is at a decent level I had no wobble or visible vibrations anymore. Cyclic gain is at 45% for now.

Sadly the vid was made from afar and quality is very bad but in my opinion it looks quite ok. I'll still have some finetuning to do but this is a sold base to start from now.

https://www.youtube.com/watch?v=KI8R5p4GpG4

[Franky13]

@Thoemse

Bist Du jetzt zufrieden mit Deinen Einstellungen, konntest Du diese verbessern?

Gruß

[ZeXx86]

Hello,

Geometry 6° value or any other should not change in any case on its own.
I recommend to verify if all Subtrims are still configured correctly and servo arms are centered when you tick Subtrim (tuning).
At the same time you should see 0° between main blades.

[Thoemse]

@Thoemse

Bist Du jetzt zufrieden mit Deinen Einstellungen, konntest Du diese verbessern?

Gruß

Not quite happy yet to be honest. The heli is flying very well and stable and I don't see any vibrations but on spoolup and especially when spooling down it is very unstable.
I never had this on any other heli but this is my only heli with a spirit. If it is the spirit or the helis fault I could not determine yet.

[ZeXx86]

Hello,

this problem is often related to rotor head dampeners or too soft landing skids.
You can use harder damepenrs if possible.

You can decrease Geometry 6 deg value in the worst case. But if it is mechanical issue, then only mechanical change will help.

[Thoemse]

Hello,

this problem is often related to rotor head dampeners or too soft landing skids.
You can use harder damepenrs if possible.

You can decrease Geometry 6 deg value in the worst case. But if it is mechanical issue, then only mechanical change will help.

I'll have to lower the deg value in that case. The landing gear is stiff carbon. Since this is not exactly a mass market heli at all there are no optional dampers for that rotorhead either.

Edit: I have to lower it to low 5 deg almost 4 deg to get rid of the shakes. It flies well still but I am loosing agility/roll rate.