sk540 tail setup - confused about center

[srhadden]

Hi all,

I'm setting up the tail servo. Steps are as follows.

1) Power on, which connects the radio.

2) Connect the USB to the computer

At this point, my tail linkages are mechanically centered. It gets weird during the wizard. See, right now all I've done is connected the sk540 to the computer, so I assume that we're in some kind of direct mode where the gyro is not involved at all.

I start the wizard. When it comes time to set the CENTER the tail servo jumps. I had just mechanically set it to center, but the sk540 software just moved it all out of whack.

So I use the rudder control and center the tail as it tells me.

Moving through the wizard it says to now mechanically adjust the linkages. I already got the linkages centered before I started the wizard.

So if I'm making any sense, I should not try to set the tail mechanically at all until I'm in that very specific step in the wizard?

[Luvmyhelis]

Lol, been there done that. Nothing you do before entering the wiz with Skookum counts. As the setup info is teaching the Skookum where center actually is, but according to its own setup way of inputting the info into the system.

Yeah, the servo jumps when entering the tail setup. Bring the servo arm to a perfect 90. Then adjust the linkage so the tail itself has zero pitch, but only when prompted. Doing it before hand doesn't count. Now nail the end points and you are done. Perfect tail if the figures are within specs.

[srhadden]

OK, looks like I got it.

So I assume it is normal for the tail servo to shift to the end when you first power on the sk540? Is this another one of those compensation for spool up things, just like the swash initalizes offset from where I set it up in the wizard...?

Thanks

[omerco]

ha? when you power the unit it goes all the way till the end?
are you using traditional Rx? did you set your fail safe? both for your Rx and SK?

[srhadden]

Yeah after the sk540 jumps twice, the tail servo slowly gives, I believe right rudder, and settles down toward the end of the throw.

I'm using a traditional Rx. I'm not sure if I set the fail safe. I'll check, but the unit comes up normally and everything is connected solid.

[gtruk]

I was having weird tail issues as well when first doing mine. Make sure you go into the advanced mode and 0 out your collective mix. I would get mine perfect when plugged into the computer but once I unplugged it, everything would go crazy. For some reason the mixes were really high and when unplugging from the comp, it would add full rudder. Not sure if yours has that but might be worth checking.

[Xrayted]

Originally Posted by gtruk

I was having weird tail issues as well when first doing mine. Make sure you go into the advanced mode and 0 out your collective mix. I would get mine perfect when plugged into the computer but once I unplugged it, everything would go crazy. For some reason the mixes were really high and when unplugging from the comp, it would add full rudder. Not sure if yours has that but might be worth checking.

This is one of those things that commonly confuses people when dealing with the tail.

The unit adds tail pre comp depending on where your collective is positioned. This isn't the case when in setup mode, so you may be perfectly centered while setting up, but the tail may jump when you unplug and let the heli go back to normal. This tricks many into thinking something is wrong when really it isn't.

In that case, the tail will only be zero pitch when your collective is centered and at zero pitch, so always make sure to center the collective when observing the setup afterward.

[srhadden]

So xray you saying start up the heli normal not connected to the computer and then go mid collective and see if the tail moves to the center?

[srhadden]

Quick update, tried this at lunch. It looks like my earlier problem is gone. I think it is because I did the servo setup with the wizard exactly like it tells you.

Starting up with low stick, sk540 inits and the tail servo moves slightly off center, a few degrees this time, rather than the huge displacement I had before. When I moved the collective to the middle the tail servo horn went to 90 like I set it up.

So, I think this is what xray was describing. I think I'm good here.

[omerco]

make sure you have tail deadband on 2 (main screen) - that could cause that.

also if you didn't set failsafe in you Rx it might do the same. do that after you finish the whole setup both for Rx and SK (top menu somewhere)

[srhadden]

What should be the failsafes in the SK software? Mid stick? or slightly negative pitch so it doesn't go flying off?

Ok, checked deadband, tail is set =2, the rest =0.

Thanks for the suggestions.

[Bonkievan]

Originally Posted by srhadden

What should be the failsafes in the SK software? Mid stick? or slightly negative pitch so it doesn't go flying off?.

I set for mid stick. Slightly negative will bring your heli down a lot quicker than you think with no HS. Not to mention the difference if you're inverted..........

Btw-You can set Failsafe/loss of signal to Self level on the SK720BE. I'd be interested to hear if anyone has unfortunately tested? Sorry for the ot srhadden.

[omerco]

Originally Posted by srhadden

What should be the failsafes in the SK software? Mid stick? or slightly negative pitch so it doesn't go flying off?

Ok, checked deadband, tail is set =2, the rest =0.

Thanks for the suggestions.

Fail safe - all center, blades 0 pitch.

Deadband- 2 for tail, 0.5 for the rest. Also verify in the gui you don't have "noise" greater then these values. I had to increase to 0.7...

[omerco]

Originally Posted by Bonkievan

I set for mid stick. Slightly negative will bring your heli down a lot quicker than you think with no HS. Not to mention the difference if you're inverted..........

Btw-You can set Failsafe/loss of signal to Self level on the SK720BE. I'd be interested to hear if anyone has unfortunately tested? Sorry for the ot srhadden.

I did...the damage was minimal: boom and main blades

[Bonkievan]

Originally Posted by omerco

I did...the damage was minimal: boom and main blades

Thanks. Good to hear.

[omerco]

That requires some luck - it really depends when it happens

[Xrayted]

Originally Posted by srhadden

So xray you saying start up the heli normal not connected to the computer and then go mid collective and see if the tail moves to the center?

Exactly....it appears from reading that you have resolved this issue now, so great!

[srhadden]

Yah, appears to be running as expected. Thanks, Xray.