Thorp Air Command - T18.net

Supporting Owners, Builders and Pilots of the Thorp T-18 and its variants.
It is currently Thu Mar 28, 2024 1:08 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 11 posts ] 
Author Message
MartyG
PostPosted: Thu Jan 20, 2022 9:52 am 
Newbie
Newbie
User avatar

Joined: Mon Jun 07, 2021 8:29 pm
Posts: 48
Location: Y51 - Viroqua, WI
Has anyone else experienced a problem with installing a pitch servo for an autopilot on their T-18?

I have GRT brand servos, but they look about the same in geometry as most other popular servos. When I hooked it all up (I should have thought to try this beforehand) the throw of the elevator tube from stop to stop is much more than the throw of the servo arm. I spoke with a friend who had this problem on his Tailwind and he just made an extension on the servo arm to fix the problem. This was my first thought also, but it also increases stress on the shear bolt on the servo.

Is there another solution that I should be thinking of? Anyone who has installed an AP on their Thorp, I would love to see some pics to spur some thoughts.

_________________
Marty G
N50LE
YouTube Channel
martygrosse@yahoo.com


Top
 Profile  
 
Ryan Allen
PostPosted: Thu Jan 20, 2022 1:34 pm 
Hero Member
Hero Member
User avatar

Joined: Wed Oct 21, 2009 6:10 pm
Posts: 1105
Images: 0
Location: Louisiana
I have Dynon autopilot system. My pitch servo required an arm (basically a piece of aluminum tubing with rod ends on both ends of the tube) to reach from the servo to the elevator tube. My pitch servo is mounted on the side of the tunnel/elevator tube cover located in the baggage area. Sorry, no pics handy.


Top
 Profile Personal album  
 
Mduroch
PostPosted: Thu Jan 20, 2022 1:52 pm 
Newbie
Newbie

Joined: Tue Oct 29, 2019 9:40 pm
Posts: 40
Hello All,

Can you guys share some photos? I am planning to install a Bendix/King Xcruze this year.

Thanks!
Mike Durocher
N2WB


Top
 Profile  
 
MartyG
PostPosted: Thu Jan 20, 2022 2:47 pm 
Newbie
Newbie
User avatar

Joined: Mon Jun 07, 2021 8:29 pm
Posts: 48
Location: Y51 - Viroqua, WI
I don't have great pics but I snapped a couple quick ones of my mount at least. Mine has a rod connecting the servo to the elevator tube also, but the travel isn't enough. **the rod is not connected in the photo. It is parallel with the elevator tube when connected**

I called GRT and they are going to send me a longer arm that bolts up to the servo, we will see if that's enough. Otherwise, I think I'm just going to have to make an extender out of some aluminum to get it to the right length.

No matter what I do the pics show up upside down, sorry about that.


Attachments:
IMG-2153.jpg
IMG-2153.jpg [ 3.37 MiB | Viewed 6443 times ]
unnamed (2).jpg
unnamed (2).jpg [ 921.85 KiB | Viewed 6443 times ]

_________________
Marty G
N50LE
YouTube Channel
martygrosse@yahoo.com
Top
 Profile  
 
david read
PostPosted: Thu Jan 20, 2022 9:35 pm 
Sr. Member
Sr. Member

Joined: Tue Oct 20, 2009 9:21 pm
Posts: 225
Location: USA
Image
I took this pic for something else but it shows how I mounted my MGL avionics servo. That is a smoke oil pump beside it.


Top
 Profile  
 
bfinney
PostPosted: Sat Jan 22, 2022 3:31 pm 
Sr. Member
Sr. Member
User avatar

Joined: Thu Oct 22, 2009 2:24 pm
Posts: 501
Images: 6
Location: Yelm, WA USA
This is my install of a Garmin GS28 servo, I had to get the longer servo arm, needed 1.75" throw and the standard arm max is 1.5". The servo is mounted on the aft side of the -571 bulkhead (the aft bagage compartment bulkhead).

Attachment:
IMG_1573.JPG
IMG_1573.JPG [ 1.47 MiB | Viewed 6376 times ]


There is something happening when photos are included, this is upside down (rotated 180deg), it displays just fine on my computer.

_________________
Bruce Finney
N18JF T-18C #262
Yelm, WA USA


Top
 Profile Personal album  
 
Mduroch
PostPosted: Mon Jan 24, 2022 12:06 pm 
Newbie
Newbie

Joined: Tue Oct 29, 2019 9:40 pm
Posts: 40
GREAT!

Thanks for all the photos! I appreciated it.

Mike Durocher


Top
 Profile  
 
campipilot
PostPosted: Sun Feb 06, 2022 11:26 pm 
Newbie
Newbie

Joined: Fri Aug 26, 2016 10:29 am
Posts: 45
Images: 0
Image

Image

Image


Top
 Profile  
 
campipilot
PostPosted: Sun Feb 06, 2022 11:30 pm 
Newbie
Newbie

Joined: Fri Aug 26, 2016 10:29 am
Posts: 45
Images: 0
Image

Image

Image

Image

Image


Top
 Profile  
 
MartyG
PostPosted: Mon Feb 28, 2022 11:07 am 
Newbie
Newbie
User avatar

Joined: Mon Jun 07, 2021 8:29 pm
Posts: 48
Location: Y51 - Viroqua, WI
Just wanted to update this with my final solution and a pic. The longer servo arm that GRT supplied me worked perfectly. I now have full elevator travel with only about 45 degrees of travel either way off center. Looks like it's all going to work out!
Image

_________________
Marty G
N50LE
YouTube Channel
martygrosse@yahoo.com


Top
 Profile  
 
Tony28031998
PostPosted: Thu Nov 02, 2023 3:42 pm 
Newbie
Newbie

Joined: Thu Aug 31, 2023 9:32 pm
Posts: 6
Hi Marty!

I am looking at GRT avionics too, and I wanted to know what rod length you got for your pitch and roll axis for your autopilot? THanks


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron

[ Time : 0.225s | 14 Queries | GZIP : On ]