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Where does the Roll Servo go?

PostPosted: Sat Mar 11, 2023 1:14 pm
by dboeshaar
Greetings!

I'm building a Sonex Model B. Expected shipping for the airframe is 3/17/2023

I'm building the wings first

I want to wait as long as possible for the avionics. Get the best upgrades.

I'm going with GRT panel

I want to have autopilot

I know the pitch servo is in the fuselage

BUT

Where is the roll servo? Since I'm building the wings now, do I need to buy the servos now?

Where do folks put the roll servo?

advTHANKSance

Dkb

Re: Where does the Roll Servo go?

PostPosted: Mon Mar 13, 2023 9:42 am
by DCASonex
Not sure how applicable my mounting in a center stick "A" series is, but you can find it here:
https://sonexfoundation.com/the-amsler-files
Auto pilot is the first category listed.

David A.

Re: Where does the Roll Servo go?

PostPosted: Mon Mar 13, 2023 11:31 am
by GordonTurner
I did put mine in the wing. Made for a nice uncluttered installation. I put the pitch servo under the seat. In the a the seat comes out, since it doesn’t in the B make sure you have maintenance/replacement (hope not…) access to anything you out there.

Here’s the link to my roll servo:

https://imgur.com/gallery/0hD4z

Best of luck, let us know what you decide.

Gordon

Re: Where does the Roll Servo go?

PostPosted: Mon Mar 13, 2023 5:18 pm
by Spaceman
I put mine under the seat like this:

http://paegelow.blogspot.com/2020/02/au ... 7.html?m=1

Re: Where does the Roll Servo go?

PostPosted: Mon Mar 13, 2023 10:59 pm
by dboeshaar
Thank you all!

This is a great help. I'll keep you in the loop as we progress.

My Airframe delivery date is THURSDAY!

Gung Ho!

(Gung = To Work, Ho = in harmony)

Dkb

Re: Where does the Roll Servo go?

PostPosted: Tue Mar 14, 2023 12:07 am
by sonex892.
Spaceman wrote:I put mine under the seat like this:

http://paegelow.blogspot.com/2020/02/au ... 7.html?m=1

There is some really good info on Chris's blog. This is very similar to the mgl servo installation in my A model.

One thing that may not be apparent with this roll servo location, is the roll movement is 3 dimensional and the roll servo arm position alters with forward and aft stick movement. The servo end stop position for hard left aileron with stick forward is not the same servo end stop position as hard left aileron with stick aft. The same goes for the right aileron. I too had to fabricate a longer servo arm for the roll servo to reduce the total angle of throw to eliminate the risk of going over center and locking the controls.

Re: Where does the Roll Servo go?

PostPosted: Tue Mar 14, 2023 9:38 am
by DCASonex
sonex892. wrote:
Spaceman wrote:I put mine under the seat like this:

http://paegelow.blogspot.com/2020/02/au ... 7.html?m=1

There is some really good info on Chris's blog. This is very similar to the mgl servo installation in my A model.

One thing that may not be apparent with this roll servo location, is the roll movement is 3 dimensional and the roll servo arm position alters with forward and aft stick movement. The servo end stop position for hard left aileron with stick forward is not the same servo end stop position as hard left aileron with stick aft. The same goes for the right aileron. I too had to fabricate a longer servo arm for the roll servo to reduce the total angle of throw to eliminate the risk of going over center and locking the controls.


I addressed this by mounting my roll servo off the base frame of my center stick so it moves with the stick. Where I located it, Its mass also helps offset some of the added pull from the bungee cord as it is stretched as stick is pushed forward.

David A.

Re: Where does the Roll Servo go?

PostPosted: Tue Mar 14, 2023 11:02 am
by daleandee
DCASonex wrote:
sonex892. wrote:
Spaceman wrote:I put mine under the seat like this:

http://paegelow.blogspot.com/2020/02/au ... 7.html?m=1


One thing that may not be apparent with this roll servo location, is the roll movement is 3 dimensional and the roll servo arm position alters with forward and aft stick movement. The servo end stop position for hard left aileron with stick forward is not the same servo end stop position as hard left aileron with stick aft. The same goes for the right aileron. I too had to fabricate a longer servo arm for the roll servo to reduce the total angle of throw to eliminate the risk of going over center and locking the controls.


I addressed this by mounting my roll servo off the base frame of my center stick so it moves with the stick. Where I located it, Its mass also helps offset some of the added pull from the bungee cord as it is stretched as stick is pushed forward.

David A.


My roll control is located under the passenger seat. I also had to extend the arm on the gold standard servo and set it up carefully to prevent not only an over center situation but also to insure that the stops on the stick were engaged slightly before the stops on the servo.

David ... your method of mounting sounds very intriguing. Any photos you'd like to share?

Dale
3.0 Corvair/Taildragger

Re: Where does the Roll Servo go?

PostPosted: Wed Mar 15, 2023 9:20 am
by DCASonex
Dale,
Photos and drawings can be found on the Sonex Foundation website:
https://sonexfoundation.com/the-amsler-files

Under heading of autopilot, which is the first in the list of my customizations.

David A.

Re: Where does the Roll Servo go?

PostPosted: Wed Mar 15, 2023 1:10 pm
by daleandee
DCASonex wrote:Dale,
Photos and drawings can be found on the Sonex Foundation website:
https://sonexfoundation.com/the-amsler-files

Under heading of autopilot, which is the first in the list of my customizations.

David A.


Excellent approach!

Thank you sir ...

Dale
3.0 Corvair/Taildragger

Edit: in looking closely at those photos I noticed the location where the roll control is attached to the stick. During my install I attempted to use that same location but found the push rod would slightly contact the seat pan so I used an extended bolt from the aileron connecting rod location.