Servo Application Guide

From DynonDocs
Jump to: navigation, search

Introduction

This configuration guide is intended to assist customers in choosing the right Dynon Avionics Autopilot servos for their aircraft.

Important Supplemental Information

Before purchasing hardware, please read our latest autopilot news update.

For answers to many questions, see the Autopilot FAQ

To order autopilot hardware, download our complete price list / order form. Fax your order to Dynon Avionics, or use it to organize before calling us at 425-402-0433.

Except where a configuration has been specifically noted to be known to work, servo suggestions are generally Dynon's best estimates based on all obtainable data at the time. As such, the servos indicated may or may not actually be the most suitable for each aircraft type. Dynon will swap out servos for alternate models should a customer find that a particular servo is sub-optimal in some way.

Available Servos

Currently, the following servos are available for purchase:

Model Number - Torque - Attachment Type
SV32 - 36 inch‐pounds - Standard Arm
SV32L - 36 inch-pounds - Long Arm
SV32C - 36 inch-pounds - Capstan

SV42 - 55 inch-pounds - Standard Arm
SV42L - 55 inch-pounds - Long Arm
SV42C - 55 inch-pounds - Capstan
SV42T - 65 inch-pounds - Linear Actuator

SV52 - 72 inch-pounds - Standard Arm
SV52L - 72 inch-pounds - Long Arm
SV52C - 72 inch-pounds - Capstan

The maximum available force will vary by the length of the arm used or diameter of the capstan employed. Standard arm servos and long arm servos (denoted by an “L” suffix) differ only in the length of their output arms. "L" servos allow for slightly more travel in aircraft that require it, at the expense of a smaller amount of available force at the longer arm attach points. Due to the decrease in available force, long arm servo models should generally only be used in aircraft that require them.

Capstan Servos: Servos that are equipped with a capstan for use in cable control systems are denoted by the "C" suffix. Popular aircraft that use these types of servos include the Zenith 601 (on the pitch axis), the Glasair Glastar series, and the Murphy Moose.

Full servo specifications are available at www.dynonavionics.com/docs.

Choosing Servos

There are a few different requirements that need to be met when choosing an autopilot servo. First, the servo employed must be able to attach to the control system safely, without decreasing control surface range-of-motion, and especially without allowing for an over-center condition. Generally, to prevent the possibility of the servo arm going over center, the servo arm must not travel more than a total of +/-60º from neutral throughout the control system's range of travel.

Additionally, the servo must be large enough to be able to drive the control surface effectively. Dynon's servos are designed to gracefully "slip" when the torque that the servo is providing is insufficient to drive the control surface. So if servo torque is insufficient for the application, it will continuously slip, the autopilot will not be able to effectively control the aircraft.

As the torque output can be adjusted in the autopilot software setup, you may be tempted to simply buy the biggest servo available and turn down the torque. This is not ideal for a couple of reasons. First, when the servos are disengaged, there is a very small amount of residual drag on the control system. As larger servos have higher residual drags, it is desirable to choose the smallest servo that can fully control the aircraft control surface. Additionally, since larger servos have bigger motors on them, they weigh slightly more as well.

So, what you are ultimately after is the smallest servo that can can successfully drive your control surface.

The aircraft configurations below are a mix of actual tested configurations and untested estimates based on the best information available to Dynon Avionics.

Specific servo/aircraft combination that have been found to work well in actual customer installations on are marked as "known to work" in the tables below, and are likely to work in your aircraft of the same type if it is a fairly standard example of that type of aircraft.

For aircraft that are not tagged as "known to work" in the tables below, Dynon's servo suggestions are estimates only. If you purchase servos and discover that they are not ideal (for example, you need more torque), Dynon will swap out servos at no charge.

If your aircraft is not listed at all in the tables below, Dynon has not performed any analysis on your aircraft type. In these cases, it might be helpful to review the suggested configuration for similar aircraft types. Keep in mind that aircraft with cable control systems will require servos equipped with capstans, which are not initially available.


Share information about your installation with Dynon!

If you have new data about an installation in a particular aircraft type, here are some ways to share what you've learned:

  • Share your installation pictures, notes, and hardware list with us by emailing them to betatest@dynonavionics.com, so we can learn from your experience. Customer installation notes will be invaluable for us as we continue to design mounting kits.
  • Share your installation documentation on the forum (forum.dynonavionics.com) under the Autopilot Installations section, so other users with similar aircraft can learn from and critique your install.
  • Add or update your aircraft's servo application guide on this page with notes about performance, etc.
  • Consider writing a new wiki article under the appropriate servo application guide on this page, documenting your install.

Aircraft Servo Configurations

RV-3

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 No
Pitch No SV32 No

Though the RV-3 has not been tested, Dynon expects good performance - similar to the rest of the tested RV line - from a pair of SV32 servos.

RV-4

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Yes
Pitch Yes SV32 Yes

A mounting kit is available for RV-4 pitch axis only. Dynon does not currently have plans to produce a roll mounting kit. However, when installed, the SV42 is known to produce good results.

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

RV-6

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV32L Outer Yes
Pitch Yes SV32 Outer Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

RV-7

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV32 Outer Yes
Pitch Yes SV32 Outer Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

RV-8

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV32 Outer Yes
Pitch Yes SV32 Outer Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

Mounting Kit part number 101020-002 (Pitch) and 101020-003 (Roll) fit both the classic RV-8 kits and the the newer "RV-8 Fuselage Kit - 1" that started shipping around September 2006.

RV-9

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV32 Middle Yes
Pitch Yes SV32 Outer Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

RV-10

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV42 TBD Yes
Pitch Yes SV42T N/A Yes

RV14

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll Yes SV42 Yes
Pitch Yes SV32 Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

Sonex

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Yes
Pitch No SV32 Yes

SeaRey

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Yes
Pitch No SV42 Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results.

This aircraft exhibits significant adverse yaw with the roll servo connected to the ailerons. There is also significant roll/yaw coupling. Testing demonstrated that the "roll" servo performs at least as well, and will less adverse yaw, when connected to the rudder.

BD-4

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42C (now available!) Not Applicable (capstan) Yes
Pitch No SV42 Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results. Aircraft has significant adverse yaw that is apparent but controllable by the autopilot.

This aircraft exhibits significant adverse yaw with the roll servo connected to the ailerons. There is also significant roll/yaw coupling. Testing demonstrated that the "roll" servo can alternatively be hooked to the rudder to effectively control the aircraft.

Cozy

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown No
Pitch No SV42 Unknown No

No known installations. Servo suggestions based on available data.

Europa

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Outer Yes
Pitch No SV32 Outer Yes

Tested on an installation similar to MOD75 & MOD76 of Europa.

Roll servo: TORQUE=100%, SENSITIVITY=20, TRN RT LMT=0, BANK LIMIT=20

Express

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Unknown No
Pitch No SV42 Unknown No

No known installations. Servo suggestions based on available data.


F-1/Harmon Rocket

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown No
Pitch No SV32 Unknown No

No known installations. Servo suggestions based on available data.


Falco

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown No
Pitch No SV32 Unknown No

No known installations. Servo suggestions based on available data.


Glasair II/III

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown No
Pitch No SV32 Unknown No

No known installations. Servo suggestions based on available data.


Glasair Glastar and Sportsman

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42C (now available!) Not Applicable (capstan) Yes
Pitch No SV42C (now available!) Not Applicable (capstan) Yes

Customer Glastar Sportsman 2+2 flew the autopilot in the Dynon test/development program with good results.

Lancair 235/260/320/Legacy

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Yes
Pitch No SV32 Yes

Customer Lancair 320 flew the autopilot in the Dynon test/development program with good results.

Lancair ES

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Unknown No
Pitch No SV42 Unknown No

No known installations. Servo suggestions based on available data.

Lancair IV-P

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV52 Middle Yes
Pitch No SV52 Middle Yes

SV42s reported to slip. Suggest SV52 for both pitch and roll. SUGGEST SETTINGS:Roll Sensitivity = 17, turn rate mode, max bank = 30 degrees, turn rate = 3.0 degres per second, Pitch = 100% torque (for the time being), sensitivity = 12, Gain = 3.0, Altitude Gain = 0.6, Pull Rate = 1.0, VSI Gain = 1.5, G Error Gain = 1.0, G Error Limit = 0.25, Vertical Climb Speed = 600'/minute, Vertical Descent Speed = 1,500'/minute, Max Air Speed = 250 knots

Lancair Turbine Legend

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 TBD Yes
Pitch No SV42 TBD Yes

Murphy Moose

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Unknown No
Pitch No SV42C (now available!) Not Applicable (capstan) No

No known installations. Servo suggestions based on available data.

Paradise P1

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Yes
Pitch No SV42 Yes

Thorp T-18

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown No
Pitch No SV32 Unknown No

No known installations. Servo suggestions based on available data.

Velocity

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Unknown yes
Pitch No SV42 Unknown yes

One known installation. Servo suggestions based on available data.

Zenith 601

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Yes
Pitch No SV32C (now available!) Not Applicable (capstan) Yes

Customer aircraft of this type flew the autopilot in the Dynon test/development program with good results

Zenith 701/750/801

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 TBD No
Pitch No SV42 TBD No

Jabiru 430

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 Unknown No
Pitch No SV42 Unknown No

No known installations. Servo suggestions based on available data, including competitive installations.

Remos G3

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 Outer Yes
Pitch No SV32 Outer Yes

Customer aircraft of this type flew the autopilot with good results. Torque 30% Sensitivity 15%

Kitfox 7

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 TBD No
Pitch No SV32 TBD No

Long-EZ

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV32 TBD Yes
Pitch No SV42 TBD Yes

Rans S-19

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 TBD Yes
Pitch No SV42 TBD Yes

Skyleader 200

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 TBD Yes
Pitch No SV42 TBD Yes

Czech Sport Aircraft SportCruiser or Pipersport

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll From Czech Sport Aircraft SV42 TBD Yes
Pitch From Czech Sport Aircraft SV32 TBD Yes

Many Installations in this popular aircraft. LAA (UK) Modification Approval Process currently in progress as at May 2009.

Aeroprakt A22/A36

Axis Dynon Mounting Kit Available Suggested Servo Type Suggested Arm Attach Point Known to work?
Roll No SV42 TBD Yes
Pitch No SV52 TBD Yes

This information was given to Dynon by Aeroprakt USA.