Collectve Swash mix changes centre pitch

[MouldyRF]

Hi all,
just installed sk360 on my minititan.

Got setup just about right with 0 pitch midstick but had +-14deg.
So I adjusted the swash mix in the sk360 from 60 to 45 to get +10 at full stick.
But then when I reteurn to centre it was abou +5 and low stick was -5 (ish from memory).

Why has the colective swash mix moved the centre point? Should I adjust this some other way?
I want to get his sorted before I set the mix for ele and aileron which are both a bit small.
For info I have used the Gaui 400 flybarless head, and have set the tx to 100% travel and 60-60-60 in the swash mixes. Also set the tx trims and subtrims to 0. So have been doing all setup in the sk360.
This was all with SK360 in setup mode.

Also have no expo or DR set.
PS. Just love watching the swash level itself while I tilt the heli around..really cool !! or am I just sad ;-)

[perfeet]

Originally Posted by MouldyRF

PS. Just love watching the swash level itself while I tilt the heli around..really cool !! or am I just sad ;-)

Not sad

[MouldyRF]

Well had no tips yet so managed to get pitch correct by lengthening the rods and now +-10deg. Cyclic is not quite 8deg bit will work that out later. Jut need some weather now to give it a go. Dont want to change servo travel yet as guess that will give me too much collective travel again.

[stmpngrnd]

Can you post a picture of your servo arms/links at mid stick? Sounds like you have some differential throw happening.

I'm running the stock 3D profile and I too had to decrease the collective on the swash mix to get down to an appropriate pitch range. I had no problems with losing the center or a balanced top/bottom range. Really sounds like a setup/geometry issue rather than something in the sk360.

hope this helps

[MouldyRF]

Ok Thanks.. Thats my suspission too as the arms are not absolutly level with quite a high trim value. So I'm going to nip out today and buy some new arms. When I built it originally I didnt realise you could get different alignment on each of the 4 90 deg arms so in my ignorance just cut random 3 spairs off!!! Now I know better.

[lakespinner2]

Originally Posted by MouldyRF

Hi all,
just installed sk360 on my minititan.


For info I have used the Gaui 400 flybarless head, and have set the tx to 100% travel and 60-60-60 in the swash mixes.

Hi MouldyRF, are you doing the swash mixing in the TX or in the sk360 ? ... just curious...

[MouldyRF]

In the sk360. I left the tx with trims at 0 and set to 90deg?? (Its a dx6i so you just have choice of 120deg or 90deg). Was aiming to do as much as I could in the sk360 to save as much coinfusion as possible. In the dx6i I think 60% swash is the default.

[oldschool269]

you want to be in single servo mode in the radio

you dont want to use 90deg swash mode in the radio.... so set that to 1 servo

and

the swash mix set at 120deg ... , set into the sk. swash settings ...

Jason

[MouldyRF]

Originally Posted by oldschool269

you want to be in single servo mode in the radio

you dont want to use 90deg swash mode in the radio.... so set that to 1 servo

and

the swash mix set at 120deg ... , set into the sk. swash settings ...

Jason

Ok just found copy of the manual and 90 deg is 1-servo mode
Quote from manual is "One Servo: 90 degrees (standard mechanical mix)

Three Servo: CCPM 120 degrees"

in the SK I do have it set to 120deg.

[MouldyRF]

Ok replaced a couple of the arms with new ones and lined them up with better mechanical centre.
Relevelled the swash with my home made swash leveler.. (m10 bolt with a 5mm hole through it and turn flat on the lathe)

Now setup is much better.
+/1 10deg colective and about 7.5deg cyclic
Thanks all

Typical...all ready to go and its snowing today!! Can't wait to try it

[CF_Machete]

hey, I just set mine up too, I zeroed the arms at mid stick, but adjusted the servo travel on the sk360to give me a max of +10 and min of -5 in regular mode (-10 in stunt). I didn't touch the mix. I have not flown my heli yet as it is dark here, but everything seems to be set correctly. 1 servo 90 on the tx and 120 mix on the sk360.

[MouldyRF]

Well got to fly it this lunch time and it flew prety well out of the box with the suggested defaults....To be honest I now can't remember if I used the default..or 3d startup settings..(most likely the default setup).
I also set the recommended 30/50 hiller/bell on the dials.

It went stright into hover really nice and almost hands off on the cyclic..couple of clicks of trim and I could take my thumb off

Did a few of the initial tests..push forward and centre and back and seemed ok..
Wind was a little gusty and that ade it wobble so perhaps a bit too much Hiller? Is that right?

Straight flight etc seems very nice and solid so VERY pleased so far.
My first landing had a bit of a lean to the right but the land was quite rough but two batteries and still in one piece.

[oldschool269]

Originally Posted by MouldyRF

Well got to fly it this lunch time and it flew prety well out of the box with the suggested defaults....To be honest I now can't remember if I used the default..or 3d startup settings..(most likely the default setup).
I also set the recommended 30/50 hiller/bell on the dials.

It went stright into hover really nice and almost hands off on the cyclic..couple of clicks of trim and I could take my thumb off

Did a few of the initial tests..push forward and centre and back and seemed ok..
Wind was a little gusty and that ade it wobble so perhaps a bit too much Hiller? Is that right?

Straight flight etc seems very nice and solid so VERY pleased so far.
My first landing had a bit of a lean to the right but the land was quite rough but two batteries and still in one piece.

Just a little to much hillier,

when its correct the heli will track spot on and hold in wind , when you go high on the hillier gain it will track towards the wind..in its own axis , ie either sideways towards the wind,(aile hillier gain to high) or forwad into the wind,(elev hillier gain to high ) or diagonal into the wind ..(both hillier gains to high )

,and as you reduce the gain you will find a point where the head will stay level , but it will drift away WITH the wind..

as with a normal gyro the in flight settings need to be loaded to give you what it will do under pressure...

i found i dropped the hillier gains on elev and aile until it no longer held square in stationary flips .

then upped them a few clicks until it held perfect ..t6hrough out the flip,
then go out and belt it through some big loops , and that will tell you if its really correct,,,

so in a static hover , you can set it up very very tight, but the more energetic the flight the less you want the SK to inter fear with your inputs ..

its a game , of cat and mouse , only airtime will help to get it where you want it,.
the hardest thing IMOO< is to figure out what the SK does, once you establish that , its not hard to tune it to a sharp point.

Jason

[MouldyRF]

Not so good today..
reduced Hiller a bit and did drift round some more but felt a bit more erratic generally.
But then I had also changed a few other settings to go somewhere between default and basic3d file.
Second flight trying to land between the puddles and it suddenly flipped on its side. It was probably me but not sure.

Any way now need two new control links, one set of servo gears, main shaft and blades
(Thankfully I had the woodies on while I played) and main gear.
Next time I'll only change one thing at a time..should know better by now!!!