MkII tail trim servo

Submitted by Anonymous on

Forums: 

From: Rob Murawski <rob [at] robmurawski.com>
Sender: <marv [at] lancaironline.net>
Subject: MkII tail trim servo
Date: Fri, 23 May 2014 12:11:59 -0400
To: <lml [at] lancaironline.net>

Hi everyone,



I'm getting ready to close-out my elevators on my MkII tail, but I also

wanted to have all of the innards in place to balance the elevator properly.

I made the bracket with the pocket for the trim servo, but with the clevises

for the Ray Allen servo, I'm not convinced it actually fits in the elevator.

Per the latest rev of the instructions, I was planning on cutting the trim

tab out after the elevator is closed, but trying to do the mock-up looks

like a tight fit.  I made a test rod which allows me to put the two clevises

right against each other and it seems like there is barely enough room to

reach the appropriate place where the hinge would be.  I think my trim tab

is the right size--it is 2" from aft to forward at BL24 which matches the

plans and drawings.



I added a picture as to what I'm talking about.  The servo is approximately

halfway to represent a neutral trim and have equal upward and downward

movements.



Is my trim servo bracket wrong?  Is my trim tab too big?  Or am I

over-thinking this?



Thanks,



-Rob

MkII tail trim servo

Submitted by Anonymous on

From: Robert R Pastusek <rpastusek [at] htii.com>
Subject: RE: [LML] MkII tail trim servo
Date: Fri, 23 May 2014 16:54:01 +0000
To: Lancair Mailing List <lml [at] lancaironline.net>
Message Header


Undecoded Message

Rob,



An easy "adjustment" is to cut a small amount from the end of each clevis to shorten the link as needed. If it gets too short, you might consider using two metal clevis instead of these FRP units--they are available from ACS, and are a bit shorter. Shortening the units provided worked for me on my IV-P; now at 1200 flight hours.



Bob



Hi everyone,



I'm getting ready to close-out my elevators on my MkII tail, but I also wanted to have all of the innards in place to balance the elevator properly.

I made the bracket with the pocket for the trim servo, but with the clevises for the Ray Allen servo, I'm not convinced it actually fits in the elevator.

Per the latest rev of the instructions, I was planning on cutting the trim tab out after the elevator is closed, but trying to do the mock-up looks like a tight fit.  I made a test rod which allows me to put the two clevises right against each other and it seems like there is barely enough room to reach the appropriate place where the hinge would be.  I think my trim tab is the right size--it is 2" from aft to forward at BL24 which matches the plans and drawings.



I added a picture as to what I'm talking about.  The servo is approximately halfway to represent a neutral trim and have equal upward and downward movements.



Is my trim servo bracket wrong?  Is my trim tab too big?  Or am I over-thinking this?



Thanks,



-Rob

MkII tail trim servo

Submitted by Anonymous on

From: Chris Zavatson <chris_zavatson [at] yahoo.com>
Sender: <marv [at] lancaironline.net>
Subject: MkII tail trim servo
Date: Tue, 27 May 2014 07:50:21 -0400
To: <lml [at] lancaironline.net>
Message Header


Undecoded Message
Rob,
You can also consider an L-shaped pushrod that is made to your final length.  I went this route so the rear elevator spar would remain intact.  Initially this bracket was simply two pieces of sheet metal, one on either side of the control horn.

Chris Zavatson
N91CZ
360std

MkII tail trim servo

Submitted by Anonymous on

From: Tim Jørgensen <tj [at] yacht-pool.dk>
Sender: <marv [at] lancaironline.net>
Subject: Re: [LML] MkII tail trim servo
Date: Tue, 27 May 2014 07:51:23 -0400
To: <lml [at] lancaironline.net>
Message Header


Undecoded Message
Is my trim
servo bracket wrong?  Is my trim tab too big?  Or am I over-thinking
this?

It looks right to me. I believe I actually had to
shorten the clevises by maybe 1/16" or so each.
 
 
Regards
Tim Jorgensen
360MKIIOB

MkII tail trim servo

Submitted by Anonymous on

From: Gary Fitzgerald <gbfitz [at] prodigy.net>
Sender: <marv [at] lancaironline.net>
Subject: RE: MkII tail trim servo
Date: Wed, 28 May 2014 07:39:14 -0400
To: <lml [at] lancaironline.net>
Message Header


Undecoded Message

Rob,



I'm sure somehow, somewhere, there's a MkII tail section where the servo,

clevises, and trim tab fit according to the picture in the plans. But it's

definitely not the one I'm building. You actually have more of your clevises

remaining than I did.



Just a few other things that may help in this phase of building:



1) Make sure to mock up the location of that servo bracket on the upper

elevator skin, temporarily attach it, put the upper elevator skin in place,

and make sure you can install the servo through the opening in the lower

elevator skin, and over the screws. Also, make sure you can get a wrench or

something into that opening to tighten the nuts that hold that servo in

place. You mak have to change the location of that bracket from where the

book says to mount it, which, naturally, will change the length of your

actuator rod.



2) Attach that servo bracket before you close out the elevator.



3) I installed the forward spar and inboard rib for the trim tab before I

closed the elevator. It seemed to make the trim tab construction go faster.



4) I can't tell from your picture if you've installed them yet, but the

location of the elevator inboard ribs is pretty important. If they're too

far inboard (as in you didn't apply enough tape to your elevator actuator to

properly simulate the 4 BID layup that covers the inboard side of these

ribs), you'll have problems with the elevator binding and not travelling

freely. Don't ask me how I know this. I think it happened to a friend. Yeah,

that's it.



Gary Fitzgerald

LNC2 ~70%

St. Charles, MO

(Still) Looking for a good deal on

a rebuildable or used (I)O-360







-----Original Message-----

From: Rob Murawski [rob [at] robmurawski.com (mailto:)

]

Sent: Friday, May 23, 2014 11:12 AM

Subject: MkII tail trim servo



Hi everyone,



I'm getting ready to close-out my elevators on my MkII tail, but I also

wanted to have all of the innards in place to balance the elevator properly.

I made the bracket with the pocket for the trim servo, but with the clevises

for the Ray Allen servo, I'm not convinced it actually fits in the elevator.

Per the latest rev of the instructions, I was planning on cutting the trim

tab out after the elevator is closed, but trying to do the mock-up looks

like a tight fit.  I made a test rod which allows me to put the two clevises

right against each other and it seems like there is barely enough room to

reach the appropriate place where the hinge would be.  I think my trim tab

is the right size--it is 2" from aft to forward at BL24 which matches the

plans and drawings.



I added a picture as to what I'm talking about.  The servo is approximately

halfway to represent a neutral trim and have equal upward and downward

movements.



Is my trim servo bracket wrong?  Is my trim tab too big?  Or am I

over-thinking this?



Thanks,



-Rob