REFLECTOR: Autopilot servos

Sun May 29 01:15:29 CDT 2011

Peter,

Here are two shots of our autopilot lateral servo installation - at the
time, it was the Blue Mtn servos, but we've since switched to TruTrak
servos, controlled by the GRT HX EFIS.  Works great cruising and for coupled
approaches, including the TruTrak's auto-pitch trim controller.  However,
rapid aircraft decelerations into the landing configuration from cruise
speeds can create situations where the TruTrak auto pitch trim can't keep up
with the trim changes required (and needs some manual help from the pilot).

This shot shows how the aileron AP servo (top center) ties into the aileron
torque arm, as seen from behind the whale tail of the keel.

Because of very limited space available in the rear cabin for electronics,
servos, etc., our aileron autopilot servo protrudes forward into the cabin
from the whale tail (shown with it's fiberglass cover), along with the ELT,
the cabin air exhaust port with servo controller, and the aileron trim motor
(with it's fiberglass cover)

Bob Jackson

N2XF

  _____  

From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Peter Braswell
Sent: Saturday, May 28, 2011 3:36 PM
To: geoff.gerhardt at gmail.com; Velocity Aircraft Owners and Builders list
Subject: Re: REFLECTOR: Autopilot servos

Geoff,
Sounds like you're making progress.  I have the SV system + AP installed in
my Glastar and absolutely love it!  Going to install the system in my
Velocity when it comes time which should be pretty cool.  If you have any
pictures of the servo installation, I'd love to see ho you've ended up
mounting them.

Good luck,
Peter

--------------------------------------------------------------
Check out:

"It's a Jungle Up There": www.zuluworks.com

Selling your Airplane? : www.fly-mart.com

Great Aviation Gear: www.sky-gadgets.com
My blog: www.icekreamkoan.com
--------------------------------------------------------------

On Sat, May 28, 2011 at 1:19 PM, Geoff Gerhardt <geoff.gerhardt at gmail.com>
wrote:

Peter,

I found the torque adjustment - its set to 100%.  After playing with it a
bit, the AP servo can control over a pretty good range before it has to be
re-trimmed.  When the AP starts to sense a load, it notifies the pilot to
trim, and which direction to trim.

Thanks.

Geoff

On Sat, May 28, 2011 at 11:20 AM, Peter Braswell <peter.braswell at gmail.com>
wrote:

Geoff

There is a torque adjustment you can do in the set up and configuration menu
if you need it.  

Peter

Sent from my iPhone

On May 28, 2011, at 9:51 AM, Geoff Gerhardt <geoff at thegerhardts.com> wrote:

Scott/John,

After playing with it a bit, and enabling altitude hold on the Dynon, I see
that it give messages to trim.  Also, I ran the test procedure again with
the trim adjusted right in the middle, the AP ran the pitch servo up and
down over the relatively small range it uses to test successfully, so I
think its functioning normal.  I'll post on the Dynon support forum just to
check, tho.  Thanks.

Looking fwd to Oshkosh - hoping to be flying there next year.

Geoff

On Sat, May 28, 2011 at 10:13 AM, Scott Derrick <
<mailto:scott at tnstaafl.net> scott at tnstaafl.net> wrote:

My Century AP asks me to adjust trim when the flight conditions change.
There is no way the AP is going to overpower the trim spring and flight
loads.

Your training the AP as to how far it "can" move. Not testing its muscle. 

I think its functioning normally but a call to Dynon may be in order.

Scott

-------- Original Message --------
Subject: REFLECTOR: Autopilot servos
From: Geoff Gerhardt  <mailto:geoff at thegerhardts.com>
<geoff at thegerhardts.com>
To: Velocity Aircraft Owners and Builders list  <mailto:reflector at tvbf.org>
<reflector at tvbf.org>
Date: 05/28/2011 05:31 AM

Hi all, 

I installed my pitch autopilot servo and powered up my Dynon Skyview to get
it calibrated.  The calibration process has you move the pitch to its
extremes to set the endpoints.  Once calibrated, it tests the servo.  I have
the Strong Pitch trim installed, so it takes quite a lot of force to
overcome the pitch trim (not sure if this is similar to the factory trim
system).  Only with my help on the stick can the autopilot servo go to the
extremes - is that normal?  Is it expected that the pilot will keep
adjusting the pitch while on AP so the servo doesn't have to work too hard?
Or, should I put a longer lever arm on the servo to increase the torque it
can deliver?

Thanks.

Geoff

_______________________________________________
To change your email address, visit
<http://www.tvbf.org/mailman/listinfo/reflector>
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!   <http://www.tvbf.org/gallery> www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives:  <http://www.tvbf.org/pipermail> www.tvbf.org/pipermail
Check old archives:  <http://www.tvbf.org/archives/velocity/maillist.html>
http://www.tvbf.org/archives/velocity/maillist.html

-- 
One of the sanest, surest, and most generous joys of life comes from being
happy over the good fortune of others.
Robert A. Heinlein

_______________________________________________
To change your email address, visit
<http://www.tvbf.org/mailman/listinfo/reflector>
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!   <http://www.tvbf.org/gallery> www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives:  <http://www.tvbf.org/pipermail> www.tvbf.org/pipermail
Check old archives:  <http://www.tvbf.org/archives/velocity/maillist.html>
http://www.tvbf.org/archives/velocity/maillist.html

_______________________________________________
To change your email address, visit
<http://www.tvbf.org/mailman/listinfo/reflector>
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!   <http://www.tvbf.org/gallery> www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives:  <http://www.tvbf.org/pipermail> www.tvbf.org/pipermail
Check old archives:  <http://www.tvbf.org/archives/velocity/maillist.html>
http://www.tvbf.org/archives/velocity/maillist.html

_______________________________________________
To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!  www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives: www.tvbf.org/pipermail
Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

_______________________________________________
To change your email address, visit
http://www.tvbf.org/mailman/listinfo/reflector

Visit the gallery!  www.tvbf.org/gallery
user:pw = tvbf:jamaicangoose
Check new archives: www.tvbf.org/pipermail
Check old archives: http://www.tvbf.org/archives/velocity/maillist.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20110529/580ef458/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 65140 bytes
Desc: not available
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20110529/580ef458/attachment-0002.jpeg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 48361 bytes
Desc: not available
URL: <http://www.tvbf.org/mailman/private/reflector/attachments/20110529/580ef458/attachment-0003.jpeg>