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  #11  
Old 05-07-2014, 10:16 AM
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Kevin Horton Kevin Horton is offline
 
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Quote:
Originally Posted by N208ET View Post
I am going back out today for another inspection and play with the servo some more. Testing the servo on the ground produced normal results. But I keep asking myself, I definitely didn't engage the servo, and the autopilot isn't suppose to function below a certain airspeed, 100 mph is what I have the lower limit set at. Is it possible for the servo to even do this? I'm heading to the airport now and will report back any findings.
Even if the autopilot is engaged, it should be possible to apply enough force through the stick to override it and fly the aircraft. If your autopilot servo is so "strong" that you cannot override it, I'd disable the autopilot. There are failure modes, or pilot misselection errors, that could lead to the autopilot being engaged when you believe it is not engaged. If you can't override the autopilot and fly the aircraft, then these situations could lead to an accident.
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  #12  
Old 05-07-2014, 10:23 AM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by humptybump View Post
If it is the servo, the autopilot should be configured that the pilot can over power the servo. Each AP is different so I'd refer to the manual or the the manufacturer for settings.
Quote:
Originally Posted by Kevin Horton View Post
Even if the autopilot is engaged, it should be possible to apply enough force through the stick to override it and fly the aircraft. ...
You are both correct and the Dynon AP is designed so you can override it. (I have the SV42 roll servo in my -9, which is the mid-sized servo.)

However, it bent the attach plate, like happened to me, it will jam the controls.
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  #13  
Old 05-07-2014, 10:44 AM
Pat Stewart Pat Stewart is offline
 
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Check and see if the pin that locks the cable on the servo wheel has popped out. This happened to me on my elevator servo and it locked it up just like yours. I sent the servo back and found out this was a known problem a few years back however corrected.
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  #14  
Old 05-07-2014, 12:10 PM
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flightlogic flightlogic is offline
 
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One additional thing to note. The software in some installations that prevents servo activation on takeoff is dependent on GPS data. If a good lock on GPS is not present... the safety feature will not work.
I trained special warfare pilots in C xxx aircraft at one point. The certified servos locked up... and the disconnect button did nothing also.
Pilot pulled the wrong breaker (down by his lower left leg) and that confused things even more. Had to land with unusual forces to over ride the clutches. It was important to keep a light but firm touch.... knowing that the servos might disengage just as quickly as they locked.... right at touchdown.
Other testing with The Chelton Autopilot (later pulled from the market... and sent to the shredder) drove the elevator trim tab. That always gave me concern, regarding a run away trim motor. We are all test pilots to some degree in the RV series.
Please.... always waggle those sticks before takeoff. Even if just a stop and go. And check trim positions... Cheers guys/gals....

Last edited by flightlogic : 05-07-2014 at 12:14 PM. Reason: details
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  #15  
Old 05-07-2014, 03:39 PM
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The recent high winds where I have been this week are a reminder to me.
Never let go of the controls. Never leave the gust lock off... even to walk over and do a quick task. Always waggle the stick before flying. When the autopilot gets power on the ground, hold tight. You are in charge... not the little motors.
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  #16  
Old 05-08-2014, 08:25 AM
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Mike S Mike S is offline
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Quote:
Originally Posted by krw5927 View Post
The OP has a non-standard installation that will produce more than a 50% increase in force over the standard installation, using the same hole in the servo arm. Given the same geometry and test routine, would the SV32 have been capable of damaging the steel brackets? Who knows. But thankfully this is the first case we've heard of.
Actually the OP was a totally different person and problem---------major thread drift has occurred here.

As to the problem in Bills plane------well, isnt that the whole purpose of doing a beta test??? find any issues and determine how to deal with them. Seems like this is all going to be a good thing in the long run.
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  #17  
Old 05-08-2014, 08:27 AM
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LettersFromFlyoverCountry LettersFromFlyoverCountry is offline
 
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Quote:
My plane has always wanted to roll left when I put in full power on the takeoff roll, so I have gotten into the habit of compensating with right aileron, a lot at first and slowly decreasing defection as speed builds up.
Just to back up a bit, I'm a little confused.

You compensate "on the roll" with right aileron?

Isn't this a rudder input situation?

I ask because I often end up left of centerline after I've left the ground and compensate THEN with aileron. I haven't had a chance to practice lately but I'm pretty sure I'm not putting enough rudder in on the roll and probably am also not coming straight back with the stick on rotation.

I realize this is not the point of your post but I was just curious.
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Last edited by LettersFromFlyoverCountry : 05-08-2014 at 03:33 PM.
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  #18  
Old 05-08-2014, 08:34 AM
krw5927 krw5927 is offline
 
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Quote:
Originally Posted by Mike S View Post
Actually the OP was a totally different person and problem---------major thread drift has occurred here.
Yikes, you're right! I even forgot who the OP was!
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  #19  
Old 05-08-2014, 10:03 AM
N208ET N208ET is offline
 
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Originally Posted by krw5927 View Post
Yikes, you're right! I even forgot who the OP was!

I'm sorry, I kinda gave up on this thread.
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  #20  
Old 05-08-2014, 10:25 AM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by N208ET View Post
I'm sorry, I kinda gave up on this thread.
Same here...
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