RV-9A Construction Log for the Elevators
Trailing Edges (thanks to Jim Cone and Todd Houg)
This page built Friday, August 8, '03, revised Saturday, August 9th.

I had a tough time with the rudder trailing edge.  It looks great on one side and like a mogul run on the other.  Looking back I did a lot wrong..experimenting with proseal for the first time, trying the back rivit technique, etc.  I also discovered afterward that I wasn't reading the most up to date instructions.(duh!).  I also did not put a slight bend in the rivet line as described early in the builders manual.  This probably would help close the very edge of the skin against the AEX wedge.

The backrivet technique will produce the smoothest side on the side against the backrivet plate.  As such this will probably still be the best way to do the elevators, ailerons, and flaps, because you have to get under the plane to see the rippled side.  At least make the judges crawl under the plane to see the rough spots!  P-)

I read Jim Cone's write up on the rudder trailing edge he worked on his RV-7.  I thought it couldn't be any worse than I had done so I put the tools together and went to work. Todd Houg had used this method on his -9A as well and it's documented on his web page.
 
 

Take an extra squeezer die and grind it off at the appropriate angle for the control surface you are working on:
RV-9 Elevators are 12 degrees
RV-7, 9 rudder is      degrees
Ailerons --I don't know yet
Just grind ONE DIE not both.  You need to make sure it's pointed in the right direction when you squeeze the rivet and you don't need to keep track of two dies!
This is a hand squeezer, I think it allows better control, your mileage may vary.
 
 
 

 
 

Try and keep the long jawed clamps on the stiffeners otherwise they might ding the thin skin.  You need to cover the area you are working on completely with clamps leaving just enough room for the squeezer.
 
 
 
 
 
 

 

Notice the masking tape pads under the long jawed clamps.  It keeps them from slipping off and from digging into the aluminum. There are about 4 or 5 layers of tape on each pad.
 
 
 
 
 
 
 
 

 

As on Jim's article the angle aluminum on the back side spans the length of the trailing edge in order to keep it straight.  The long jawed clamps keep it pulled into allignment.
 
 
 
 
 
 
 
 

 

Not bad at first glance, let's look closer...

If you've done this you'll recognize this as the top side of the left elevator.
 
 
 
 
 
 
 
 

From the bottom side..
good from a distance.
 

Pretty straight (sorry, I thought I had a shot straight down the edge..I'll get it later)
 
 
 

Rivets fill the dimple very well and the ripple factor is very subdued.  This trailing edge has no Pro-Seal on the AEX wedge.  As you can see below there is some puckering between a couple of rivets in three places.  I'm sure this was due to my riveting sequence as I was experimenting as I went along.  It took about 10 rivets and 5 trips to the grinder before I was happy with the angle of the die.

I didn't have any special equipment to grind the die.  The die was a broken dimple die that Columbia Airmotive had and they just gave it to me.  You could use any flush squeezer die that is about 1/4" thick.  Used a little geometry and a calculator along with a cheap set of vernier calipers to get the initial measurements for grinding the die.  Marked it up with a sharpie and headed for the bench grinder and eye-balled it.  Held it with vice grips, did the coarse work on a stone and polished it with the scotch brite wheel.  You don't want a perfect smooth finish on the die.  It needs a slight "tooth" to grip the buck tail of the rivet so you have some control while seating it and the squeezer doesn't try to slip off.  How much tooth?  I don't know, just not a mirror finish, maybe about 320 or 400 grit or equivalent

 

You tell me..
Is it shop?

or is it manufactured?
 
 
 

The right elevator results and conclusion
 
 
 
 
 

Back to the home page for Diana's RV-9A