What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Electric Elevator Trim

R

RV-4

Well Known Member
To anyone who may have done this before...

How hard is it to retrofit an Electric Elevator Trim to a completed,flying RV-4 stab?

With the new Dynon autotrim function for the Skyview I thinking of doing the mode if it is possible..

Thanks

Bruno
[email protected]
 
Its not hard. I have retrofitted a couple of 4s. It can be done several ways. The traditional way is to reopen the elevator install the doubler and the brakets and the motor and retrofit your tab.
I have also seen a few people who have

A. Removed the trim lever and incorporated a bracket and installed the motor in the cockpit.

B. Bought a short trim cable (these can be found in boat shops or speed shops such as Jegs, Summit and may even be found in spruce) removed the long cable replaced it with the short one and set up the trim motor somewhere aft fueselage.

A&B require no damage to your paint and are by far the easiest. And of course the advantages are no damaged paint and no rebalance of the elevator.
Ryan
 
Elevator Trim

Hi Ryan

Thanks for the info, it's much appreciated.

Can the parts be purchase from Van's ?

You wouldn't have any pictures that you could send me wouldn't you??

Cheers

Bruno
[email protected]
 
Sorry I don't have any pictures. Vans still sells an electric trim kit for pre punched and non per punched elevators, check their online catalog under airframe and cockpit accessories.
If you chose to go the cable route you can go to the Jegs website and search push pull cables or google push pull cables and you can find what you need.
The cables can be bought for a fairly low price. I haven't shopped for a trim motor by itself so not sure of prices there.
Hope this helps,
Ryan
 
Elevator Trim

Thanks Ryan..

I'll check the Jegs & Vans website

Cheers

Bruno

---------------------------------------------
 
A simpler mod would be to install the "gretz" style electric trim. This mounts the ray allen servo on a bracket under the tail intersection fairing and connects to the trim tab via a short push-pull cable. I say gretz style as he used to sell a kit that provided all the needed parts.

Added advantage is easy access for repairs and lack of added weight to the elevator.
 
I had thought about The Gretz conversion but I don't think he does it anymore. His contact info is

You can phone us at 520-730-3818, you can also contact us at our e-mail address: [email protected]

Won't hurt to ask.
Ryan
 
Elevator Trim

Richard & Ryan

Thank you for the info Guys, that is the way I will be doing mine if I decide to do the mode...much simpler application.

Another poster send me an e-mail with a link to Randy Lervold RV-3 website and that is how Randy did it on his -3.

I'll also check with W. Gretz to see if he still has a kit for sale.

Thanks again

Bruno
 
I emailed [email protected] in 2011 and never got a response. I was looking for a conversion for my -8. Just in case someone is considering doing this on an -8, here are the part number comparison.

elevator%20trim%20parts-M.png


If someone can get Mr. Gretz to make some kits I'd take one for my -8.
 
About the only part that needs to be bought is the cable. The bracket is easily made from some 0.063 aluminum and a piece of 3/4x3/4 angle (1/8 or 1/16") and a few rivets.

IIRC the cable is about 18"long or so. one would need to measure this so that the bracket can be installed under the intersection fairing. I probably have the gretz drawings someplace but where is the big question....
 
I removed my cable

I did this mod a number of years ago. I opted for putting the servo in the elevator and removed that big old heavy cable. You will lose some weight in the tail, always a good thing in the -4.

PS Anyone want to buy my cable?
 
Last edited:
Elevator Trim

I like Tony's idea of installing the servo in the front rather than in the back.

Tony, I can't read the model of servo you used, can you tell us what it is...?

Thanks

Bruno
[email protected]
 
You must log in or register to reply here.
Back
Top