RV-4 Autopilot

[Fly2eat]

Originally Posted by FinnFlyer

Can easily be in the RV-4 stick well so won't interfere with passenger foot wells.

And the "bracket" attached to the stick weldment is very easy to make.

Finn

Hi Finn,
I see the control springs attached to a bracket on the bottom of the control stick. What is the longer part of that bracket that runs up the front side of the stick?
L. D.

[Scott Hersha]

That is the manual trim lever, a spring biased system that works very well for manual aileron trim. This of course won’t allow your autopilot control system to auto trim your airplane.

[FinnFlyer]

Originally Posted by Scott Hersha

That is the manual trim lever, a spring biased system that works very well for manual aileron trim. This of course won’t allow your autopilot control system to auto trim your airplane.

That's right. And I don't have that. See post #18 for a picture of my installation. I have electric aileron trim (small trim tab on left aileron similar to elevator trim tab).

Finn

[Fly2eat]

Thanks Scott and Finn. Mine were matched drilled wings so hopefully won't need aileron trim. I don't have it so I guess I'll find out on first flight!

[Freemasm]

Originally Posted by Fly2eat

Thanks Scott and Finn. Mine were matched drilled wings so hopefully won't need aileron trim. I don't have it so I guess I'll find out on first flight!

Don't know what kind of flying you're planning. Regardless, I'd suspect you'll need some type of roll trim. Not building a 4 but close enough. If there's an easier/better way to effect it than the last post here, I'd like to know for myself.

https://vansairforce.com/community/s...d.php?t=182781

[FinnFlyer]

Just because of left and right tanks I think you'll find that you will want some kind of roll trim -- unless you have an autopilot.

Reason I installed the electric roll trim was with poor man's wing leveler in mind. (Figured I could rig up something simple with mercury switches or something.)

Then, because I got the Dynon D-100, I talked myself into buying used Dynon servos when I saw them advertised here. So probably really won't need the roll trim.

Finn

[gggflyer]

What dynon servo did you guys use for the rv4 roll installed in fuselage.

Im trying to figure out if it is the long version or standard version of the dynon servo.

[FinnFlyer]

I think it's the SV42, normal arm.

Finn

[Freemasm]

Settled on the approach a la’ Finnflyer and Mr Hersha. Took a while
but the kinematics work out and there’s clearance for any item/fastener replacement and the 2” duct to route beneath the servo. Pay no attention to the linkage fastener length. Those are just temps to check out the mechanics. Two differences, at least that I’m aware of.

My column attachment bracket is 063 aluminum. If I can find a shoulder/step washer to use at the linkage attachment, I’ll use that. Any leads, please let me know. Otherwise, I’ll make a bushing out of steel tubing. Could also quickly make a replacement out of 4130.

I only connected the aforementioned bracket with the two #8 screws. The third “out of force plane” fastener made no sense to me. The forces applied by the actuator are quite low and each fastener has ~ 1700 lbs ultimate tension and single shear. If further reasoning is comforting, the actuator only attaches with 4@#4 screws.

Thanks to all the thread contributors. Thoughts, gentlemen?

[FinnFlyer]

Looks fine.

We tend to overbuild things.

Finn