Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Trim tab movement

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Europa-List
View previous topic :: View next topic  
Author Message
keithhickling(at)clear.ne
Guest





PostPosted: Tue Jul 11, 2006 11:30 pm    Post subject: Trim tab movement Reply with quote

Hello all,
 
I have just installed the trim servo / bellcrank and trim tab link rod. On checking the relative movement of trim tabs and tailplanes (starting with tabs level with tailplanes in neutral position and trim servo mid position), the movements are as specified in the manual with the tailplane moved trailing edge up 12 degrees (TP 12 degrees up, tab 27.6 degrees up or 15.6 relative to tailplane, exactly the specified amount). But moving the tailplane 4 degrees down, the tab moves 8.5 degrees down or 4.5 deg relative to the tailplane. This is less than the acceptable range of 4.8 to 6 degrees specified in the manual. I have the specified 6 degrees movement each way with the trim servo.
 
The manual doesn't say what to do about this though. The manual says the tab should move relative to the tailplane with a ratio of 1.3 to 1.  But looking at the design, it seems that the relative movement of the tabs must progressively reduce as the tailplane moves trailing edge down because the link rod is moving closer to the torque tube.
 
Can anyone tell me whether this is a real problem, and if so how to correct it?
 
Regards,
Keith Hickling
New Zealand
Kit 613
 


- The Matronics Europa-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List
Back to top
terrys(at)cisco.com
Guest





PostPosted: Wed Jul 12, 2006 9:02 am    Post subject: Trim tab movement Reply with quote

We had a similar problem during our build.  After staring at the geometry for a long while, we came to the conclusion that the height of the servo on the bulkhead contributes to size of the ratio between the tail planes and the anti-servo tabs.  As I recall, we did some calculations on how much more anti-servo travel we needed and raised (or was it lowered?) the servo mounting location accordingly, giving the desired 1.3:1 ratio.  While at it, we mounted the servo with anchor nuts on the back side of the bulkhead, and allen screws on the servo side to facilitate one handed removal of the servo mounting screws in the future, if we ever needed to change out the servo (once everything is closed up in that area).
 
regards,
Terry Seaver

From: owner-europa-list-server(at)matronics.com [mailto:owner-europa-list-server(at)matronics.com] On Behalf Of Keith Hickling
Sent: Wednesday, July 12, 2006 12:26 AM
To: Eurpoa List
Subject: Trim tab movement

Hello all,
 
I have just installed the trim servo / bellcrank and trim tab link rod. On checking the relative movement of trim tabs and tailplanes (starting with tabs level with tailplanes in neutral position and trim servo mid position), the movements are as specified in the manual with the tailplane moved trailing edge up 12 degrees (TP 12 degrees up, tab 27.6 degrees up or 15.6 relative to tailplane, exactly the specified amount). But moving the tailplane 4 degrees down, the tab moves 8.5 degrees down or 4.5 deg relative to the tailplane. This is less than the acceptable range of 4.8 to 6 degrees specified in the manual. I have the specified 6 degrees movement each way with the trim servo.
 
The manual doesn't say what to do about this though. The manual says the tab should move relative to the tailplane with a ratio of 1.3 to 1.  But looking at the design, it seems that the relative movement of the tabs must progressively reduce as the tailplane moves trailing edge down because the link rod is moving closer to the torque tube.
 
Can anyone tell me whether this is a real problem, and if so how to correct it?
 
Regards,
Keith Hickling
New Zealand
Kit 613
 


- The Matronics Europa-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Europa-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
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 vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group