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prkaye

Well Known Member
With my empennage kit I got the electric elevator trim option. This comes in a little box with a couple of electrical components.
Just wondering when during the empennage construction this gets installed. I've put it aside for now... do the plans give instructions for installing this optional trim unit?
 
Elevator

It goes in the left elevator. There is an access plate you will install as part of the normal builing process. The black box will get mounted directly on that access plate. I believe I did some test fits before closing up the elevator. Once you do the test fits and get it mounted on that access plate, you're done.

By the way, at first it may seem impossible to get that little bugger to fit through the opening while it's mounted on the plate. Be patient, try everything. It WILL fit. (Many folks trim some metal in places to make it a little simpler. I think I ground off the edge of one nutplate.
 
thanks... what about wiring? Do I need to run any wires through the empennage for the trim unit before I close it up?
 
The trim is the last thing to install

You will make the trim early and it will be the very last thing to install (just before the seat belts..:)..).

you do not need to run a wire in the elevattor beforhand but you will need to run the wires to the tail. I terminated the wires in a termanal block that I rivetted to the the flat part of the fuse under the vertical stab.

The wires fish thru the elevator/empanage OK...its a bit fiddly but not too bad.

As I painted mine before flying I didn't want to have a pull wire dangling out of the empanage.

Frank

RV7A...Inspection next Tuesday!!!!!
 
question Prkaye

I am going to be doing an -8, can I add the electric elevator trim after I build the tail or is that not advisable?

Brent
 
trim servo mounting

vmirv8bldr said:
By the way, at first it may seem impossible to get that little bugger to fit through the opening while it's mounted on the plate. Be patient, try everything. It WILL fit. (Many folks trim some metal in places to make it a little simpler. I think I ground off the edge of one nutplate.
Click to expand...

ain't it the truth!!!! first i though i must have mis-drilled the holes for the z-shaped standoffs, so i made another trim cover plate. then i discovered that i had made my replacement plate out of 025 instead of 032 (or vice versa, whichever it was), so i made another one. it didn't fit any better than the original. you sort of have to rooster it (i had a different word but the porn catcher censored it) one way, get most of it in, then sort of twist it to get it the rest of the way in.

anybody want a coupla spare trim servo cover plates? ;)
 
When you get to the trim servo part, I have some suggestions. They apply to the -7, but I am not sure if they are applicable to the -9.

A) Wait until you have the trim tab mounted and the position of the trim tab horn is known before mounting the servo brackets to the cover. In addition, don't blindy follow the instructions (dimensions) on the plans for mounting the z-brackets to the cover. Instead, draw a line where Van's wants you to and then verify the alignment with the servo attached to the brackets before drilling any holes. I found, and I have seen several others, where the servo has been off to one side by as much as 1/8" when the dimensions given are followed without verification. Go here and here for pics and a better explanation.

B) In a similar area, don't dimple the aft holes for the trim motor z-brackets and cover. Use Oops rivets (NAS1097) instead. If you dimple the aft holes, the shop head of the rivet can prevent the motor from sitting flush against the z-brackets. It happened to me on the -7, and it may not be and issue on the -9, but I have seen (online) where it has happened to others. You can always make a shim or use washers, but if you use Oops rivets, you don't have to. Pic here.

Good luck!
 
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