autopilot

[dspender]

Is three position autopilot 1) pitch, 2) roll, 3) altitude?
Am working on the 10 empennage. Do I need to install, at any point in this stage, servos or connections to prepare for autopilot?
Is rudder trim accomplished electronically or with a bendable table on the trailing edge of the rudder? Last night I used tank seal to close the aft edge of the rudder. If a trim tab is to be attached, when would that occur?
Thank you.

 

[Mike S]

The elevator servo mounts right behind the battery, so you do not need to deal with it at this time.

There are various choices for rudder trim, a fixed wedge or tab, a spring arrangement that attaches at the rudder pedal mounting tubes, or a movable servo driven tab on the rudder itself-----this you have to create on your own.

For the servo driven rudder trim, you can cut in an inset tab like I have, or add a strip of piano hinge to the trailing edge. Here is an example of the piano hinge style.

Lots of good info, and photos in the RV 10 forum, just do some searching. Be sure to change the default setting in search to any time as it is set to limit to a year.

Here is mine.

 

[BobTurner]

A 3 axis autopilot would be roll, pitch, yaw. The pitch part will hold altitude.
The third axis is sometimes called a yaw dampener. Very few RVs have one installed. There are all sorts of possibilities, from autopilots which just hold altitude to those which can follow an ILS approach. You can install pretty much all of these after the build, although it is helpful to lay in the wiring (or leave a conduit and pull strong) before closing up the wing and area under the floor.
For rudder trim, I have the simple wedge (fixed) described by Mike and it works just fine for me. It does mean I have to hold right rudder during climb.

 

[dspender]

When is the simple wedge installed. I have used tank sealant on the trailing edge and riveted the stiffeners. Should I install the wedge now as I final rivet the trailing edge of later?

 

[Mike S]

Later, it is a fit and test and repeat until happy kind of thing.

Be sure you have wheel pants and all the various fairings installed first.

 

[rleffler]

I originally was going with the Vic Syracuse version of the electric rudder trim. I had fabricated all the parts, but about the same time, Geoff at Aerosport Products came out with his spring based rudder trim module. It's a much more simplistic solution than the electric rudder trim. I switched direction and installed the Aerosport Products trim. It's a thirty minute install, even in a flying RV.

 

[JDanno]

TruTrac and Trio autopilots both use two servos only with the aileron servo keeping the wings level and making the horizontal turns. Think of making turns with your feet flat on the floor.

 

[flion]

I can't speak for the Trio, but some of the TruTrak systems can be three-axis, which requires a third servo for the rudder. This is different than the rudder trim servo. I am putting a Sorcerer in my RV-10 with the pitch servo in the tailcone along with the Van's-supplied trim servo. The roll and aileron trim servos are going in the wing. I am installing an electric trim in the rudder but I decided against the rudder servo, which installs in the tailcone and drives the rudder cables with lanyard attachments. This also means that I did not go with the yaw dampener option.

While I agree with Mike S that you can defer some of this work, it will be much easier to install as you build the tail cone. Part of the reason I am leaving off the rudder servo is that access will be nil because I already have A/C and O2 systems back there. I installed my pitch servo early to make sure I had room for those systems without interference. When building, especially before any skins get riveted on, I try to consider things like optional equipment mounting, control linkage runs, and wire/tubing runs.