Skyview autopilot

[Denok]

HI,
I have installed in my RV7 an autopilot system running Skyview OS version 3.1 and SV32 servos. I calibrated the servos using the calibration wizard and everything went ok. Got the calibration successfull message and the system detected the servos. After the calibration sequence, the system asks you to run the test procedure but at this point NADA....nothing moved when the stick should have gone to a corner position.
I called product support and was told they beleived BOTH my servos were bad or they were too small to move the controls. I tried to explain that my RV7 could be flown with two fingers and that if my airplane's controls were too heavy, I would still feel something...maybe a jolt. In any case, the servos did not engage and the controls could be moved easily in test mode when thay should have been engaged. Tech support advised that I should ship both(brand new) servos for servicing. Did some tests today and so far wiring seens OK. I'm doubtfull BOTH servos are bad and think it might be something else. Problem is that I don't know what.  :-/. Any advice, ideas.
Thanks
Denis

 

[dynonsupport]

If the disconnect switch is permanently grounded, that can lead to some odd behavior during the servo test sequence. It should be normally open, with a momentary ground when it's depressed.

 

[jakej]

Denis

As DS says....... but make sure it is a NO (normally open) switch not an NC type which can give similar symptoms. If you have the resistor fitted check the wiring of that too.

Jake J

 

[Denok]

Hello,
The switch is a NO type switch and it is only grounded when depressed. Had a resistor fitted that was 4.7k ohms. I know Dynon calls for a 5k resistor so I removed it completely. When I tried to recalibrate the servos, I was unable because the system showed an airspeed 47 knots.....in the hangar!!!!!!!which prohibited me from accessing the autopilot menu.
I'll try reinstalling 3.1 and do some more tests (outside this time) but things are not getting better.  
Denis

 

[jakej]

Denis

Does disconnecting the pitot line at ADAHRS make any difference to indicated airspeed in hangar ?

Jake J

 

[Denok]

Jake J,
I'll try disconnecting disconnecting the pitot at ADAHRS tomorrow, but first let me explain what happened today.
Brought the airpane outside (no wind day) and with engine running, still had approximatly 45 kts IAS with brakes on the flight path marker was going all over the place. ( I have a video)I was still unable to access any configuration menus. About 3 hours later, when the airplane was inside I decided to make another configuration trial. To my amazement,, when I turned on the system IAS was at 0. I then  tried to reinstall Skyview 3.1 but the system would not let me reinstall 3.1 over the existing 3.1. I went through the configuration wizard after which the system asked me do a test of the autopilot. For the first time ever, the test was flawless!!! That solves a lot of questions like wiring but leaves many questions unanswered like what can, at one point, make my system go haywire and a few hours later make it work fine? Do you think I should hard reboot the system and reinstall 3.1 (if it can be done)? Is my skyview the one to blame or the servos?
Thanks
Denis

 

[dynonsupport]

A reinstall of 3.1 can't be done (and wouldn't change anything, which is why it's not a valid operation). I think (but am not certain - I don't have a system next to me) that servo cal is inhibited if there is any IAS. I'd figure out the source of that first. If you're getting erroneous IAS that isn't somehow related to the pitot/static inputs, we should probably see your ADAHRS.

 

[jakej]

Jake J,
I'll try disconnecting disconnecting the pitot at ADAHRS tomorrow, but first let me explain what happened today.
Brought the airpane outside (no wind day) and with engine running, still had approximatly 45 kts IAS with brakes on the flight path marker was going all over the place. ( I have a video)I was still unable to access any configuration menus. About 3 hours later, when the airplane was inside I decided to make another configuration trial. To my amazement,, when I turned on the system IAS was at 0. I then  tried to reinstall Skyview 3.1 but the system would not let me reinstall 3.1 over the existing 3.1. I went through the configuration wizard after which the system asked me do a test of the autopilot. For the first time ever, the test was flawless!!! That solves a lot of questions like wiring but leaves many questions unanswered like what can, at one point, make my system go haywire and a few hours later make it work fine? Do you think I should hard reboot the system and reinstall 3.1 (if it can be done)? Is my skyview the one to blame or the servos?
Thanks
Denis[/quote

In that case I'd still test without the pitot connected at ADAHRS then try it with static disconnected - most likely NOT your SV or A/P giving you issues but , as DS says, it could be the ADAHRS.

Jake J

 

[Denok]

Hello,
I have spent many hours trying to reproduce the symptoms my system has had for the last week but for some reasons it is working fine so far. Did tests with pitot and/or static disconnected from ADAHRS and I did not find any changes. I have done no modifications or adjustments since it decided to work and I'm puzzled by the fact that at one point all symptoms stoped. I'm somewhat worried they'll come back at an unwanted time. If you would lime to see the symtoms my skyview has, please email me and I'll send you the video. In any case, should I have Dynon check my ADAHRS?
Thanks
Denis :-/

 

[Denok]

Tried to go flying today. Symptomes are back. On runup between 0 and 30 kts IAS.  

 

[DBRV10]

I believe you have a static source error.

Most likely an insect built a nest in your static and or possibly the pitot tube.

My bet is there is water in your static line.

Also when you do your engine runup, there is a large change in air pressure around the static source point, this only happens on the ground so do not worry too much. I often see airspeed changes and altitude changes during a runup and during the takeoff roll until I get closer to the Vr speed by then its all OK.

At the point of rotation you may see a momentary error as well.

Many certified aircraft have a PEC chart for static errors in the landing configuration and this applies to ILS approaches.

Check that the lines are all clear.

DB

 

[jakej]

David

Static system issues - that's what I've been trying to get Denis to figure out.

Denis I'm not sure if you did this specifically but disconnect the static line and then do the run up - IF all is ok then you do have a partial blockage caused by water or kinked static line.

Jake J

 

[Denok]

Tested all lines and all are free from water or foreign objects. That was one of the first tests I did. I'm at a point where I'll send my ADAHRS for servicing at Dynon. I think that it is the most probable source of my problems.

 

[dynonsupport]

As you've suggested, give tech support a call at 425-402-0433 for a bit more personal attention to your issue.

 

[Bruno]

Denis
       Did you find the cause of your problems....I will be installing my Skyview with the autopilot in my RV-4 soon and it will be nice to know the solution of this problem if I ever face a situation like that..?

Thanks

Bruno