A/P stiff override and continuous moving--Berkut

[tdarden]

I recently bought a Berkut (like Long EZ) with a FlightDEK D180 and HS 34 control unit. I am not sure what model servos it uses, but they are Dynons.

On the ground, with A/P activated for heading and altitude hold, the stick force to override is very high. I was reluctant to move it because of the force needed, and when I did move it in pitch, it sounded kind of like a ratchet moving, or like gear teeth were slipping. Reading your literature about override force, obviously this is not correct. What causes this, and how should I adjust it?

Also, I operated the unit on the ground with the engine off, so I could hear and observe its action, and when it was activated for heading and altitude hold, the servos were moving a lot, kind of "chattering." Should they be moving if the plane is not moving and the heading is synched? In other words, why would they be trying to adjust ALT or HDG when it was dead on?

Broadly, the FlightDEK seems like a remarkable unit, more capable than the Avidyne in my SR22. Congrats, based on what I have seen so far.

Incidentally, is the 7" Skyview unit interchangeable with what I have now (HS34, DSAB, D180)? Would I have to change wiring, or does it accept the same plugs and pitot/AOA plumbing as the D180? How about servos?

 

[Brantel]

Re: A/P stiff override and continuous moving--Berk

Look at the install manual and set the %torque to a value you are comfortable overriding but not so lose that the servo slips all the time in flight.

The ratchet comes from the fact that these are stepper servos.

The AP on the ground will constantly be moving. Perfectly normal...

 

[tdarden]

Re: A/P stiff override and continuous moving--Berk

Look at the install manual and set the %torque to a value you are comfortable overriding but not so lose that the servo slips all the time in flight.

The ratchet comes from the fact that these are stepper servos.

The AP on the ground will constantly be moving.  Perfectly normal...

Thanks, I performed the calibration and it worked as described to reduce the override load. I will flight test to be sure it does not slip. Appreciate the help.