Planning avionics upgrade RV-4

[N402RH]

Here is a post from the owner of my old RV-4 after he upgraded the panel.

http://www.vansairforce.com/communit...842#post839842

AF-5500 EFIS, Dynon D6, AF-Pilot, GTN-650, Audio Panel


We are getting ready to upgrade the panels in two RV-4's from old steam gauges to Advanced Quick panels.
Since our panels use the Advanced Control Module you can easily add the GPS Navigator at a later date.
We can pre-cut the panel for the navigator and then when you're ready we send the navigator with the harness to plug into the control module.

If you have any questions give me a call.

Rob Hickman
Advanced Flight Systems
N402RH RV-10

[SMO]

Here is my 2 cents worth.

The -4 has a very nice, somewhat sensitive, feel to it when flying. Could adding autopilot servos change that, depending on the servo? Some servos can be felt through the stick even though they are not energized. Other servos release until they are energized, exhibiting virtually no feel through the stick when flying with the autopilot turned off.

Is this an issue? Maybe, maybe not. You won't know unless you can try these for yourself.

My Rocket has the servos that can always be felt through the control system; my aileron stiffness is exacerbated by a torque enhancer installed on the aileron servo. The autopilot works very well but adds some undesired stiffness to the control system.

I believe this stiffness contributes to a certain amount of instability - aircraft does not return to straight and level after an upset (turbulence) as easily as it would without the interference of the servos. If I were doing it over I would definitely research systems whose servos are released until energized.

[WhiskeyMike]

Originally Posted by SMO

I believe this stiffness contributes to a certain amount of instability - aircraft does not return to straight and level after an upset (turbulence) as easily as it would without the interference of the servos. If I were doing it over I would definitely research systems whose servos are released until energized.

Pardon le drift, but do you know of any AP systems whose servos are released until energized?

[SMO]

Originally Posted by WhiskeyMike

Pardon le drift, but do you know of any AP systems whose servos are released until energized?

IIRC the Garmin servos work this way, there may be others.

[Bill_H]

Dynon AP servos are powered from ships power via a switch. When unpowered or when powered and the AP is inactive, they do not produce friction in the controls. You should consider a single screen 10 inch Dynon Skyview with 1 ADAHRS for both VFR and IFR. It has a 1-Hr backup battery if you lost ships power. For IFR add a Dynon D1 or D2 for the emergency attitude backup.

[BobTurner]

Originally Posted by WhiskeyMike

Pardon le drift, but do you know of any AP systems whose servos are released until energized?

The Trio servos use a clutch which is disengaged when the servos are off - no drag.

[dealfair]

My Trio doesn't have any drag when it's off. Love it.

Cheers,

[TrutrakTech]

Originally Posted by Bill_H

Dynon AP servos are powered from ships power via a switch. When unpowered or when powered and the AP is inactive, they do not produce friction in the controls. You should consider a single screen 10 inch Dynon Skyview with 1 ADAHRS for both VFR and IFR. It has a 1-Hr backup battery if you lost ships power. For IFR add a Dynon D1 or D2 for the emergency attitude backup.

Just as an FYI, Dynon servos are mechanically identical to Trutrak servos...as are GRT servos....and MGL servos (minus some mounting hole differences). Carry on!