RV-9 RUDDER

In June of 2004, I received the RV-9 rudder.  It sat in a box in my garage in Tennessee until August 15, 2005.  On that date I finally started to construct it.  I never felt any urgency to complete it since the original RV-7 rudder was already assembled.

RV-9 Rudder shipping box RV-9 rudder parts

 

Upper left photo is of the box the RV-9 rudder came in.  To the right is a picture of the detail parts as they came out of the box.

 

Trimming the stiffeners Stiffeners half done

Step one for me was to trim and fit the internal stiffeners.  Unlike the other control surfaces, all of the stiffeners were the same length and had to be trimmed for length as well as tapering the vertical flange.  The photo upper left was taken just after I started.  At right is a photo taken after the parts had the vertical flange tapered.  I did not take any more pictures of the trimming process.   

Dimpling the skins Miss-trimmed F-710

 

The next thing that I did was to dimple the rivet holes in the skins (upper left).  I countersunk the holes in the lower rib and the vertical spar instead of dimpling them (not shown).  Upper right is a photo of a mistake.  The R-710 horn brace needs to be trimmed.  It has two holes in each flange that needs to be trimmed similar to the notches in the stiffeners.  Further, the holes are approximately on the trim line shown on the drawing.  I trimmed the flanges to the holes without double checking.  Needless to say, the picture above right shows that I trimmed too much. 

 

F-710 repair part Etched and alodined parts

I had two choices, 1) order a new part or, 2) repair the existing one.  I chose 2).  The picture above left shows my repair on one of the flanges.  Having a lot of experience with sheet metal does not automatically instill you with talent but it does give you the mental resources needed to correct mistakes.  I would not have made this mistake had I double checked before trimming.  I spent more time repairing than I would have spent double checking before cutting.  Upper right is a photo of the rudder parts after etch and alodine.

Priming the RV-9 rudder parts Rudder parts after prime

 

Above are two photos of the rudder being primed.  There were 34 parts in all including the two extra ones needed to repair the F-710.

 

Spar reinforcement installation Starting the stiffener installation

After the primer was dry, I installed the three reinforcements for the rod end nutplates.  I installed the upper two nutplates and decided to wait on the lower one to make sure it was not in the way of installing the F-710.  Next I started on the stiffeners (above right).

Stiffeners installed on left skin Removing protective coating on right skin

 

Above left is a photo of all of the stiffeners installed on the left skin.  Above right is a photo of the right skin after I removed the protective coating from around the rivet lines in preparation for installing the stiffeners.  I did not photo the process on the left skin.

 

Beginning final assembly F-710 installation

Above left is a picture of the beginning of the final assembly. The R-902 spar is attached to the R-904 lower rib.  The F-710 rudder horn is next (above right). 

F-710 installed Spar to lower rib assembly complete

 

Above left is a photo of the F-710 rudder horn.  The upper arrow is pointing to the rivets in my repair.  The lower arrow is pointing to the F-917 shim that needs to be made and installed.  The right photo shows the skeleton (?) just before the first skin was installed.

 

Right skin installation Right skin installed

The right skin has been cleco'd in place ready for riveting in the photo above left.  At right is a picture of the RH skin after it was installed.

Both skins installed and trailing edge cleco'd Waiting for sealer to dry

 

The photo above left shows the rudder with the trailing edge cleco'd to a piece of wood.  At this point, the left skin had been attached (sorry no photo taken during left skin attachment).  I had mixed some fuel tank sealer, A-1/2, and spread it on both sides of the R-916 trailing edge.  I put tape on the skins to help keep excess sealer out of the dimples and to make clean up easier.  The wood was to help keep the assembly straight until I had all of the clecos in.   At that point I put the trailing edge area over the side of the table and removed the board.  As it turned out, using the board was probably a waste of time.  Anyway, I left the rudder in the position shown above right until the sealer set up.

 

Lower rib Preparation for trailing edge riveting

Above left is a photo of the F-904 bottom rib with the F-918 attach strips installed.  I still haven't installed the lower nutplate at this point but I wish I had done it while installing the rudder horn and lower reinforcement plate, R-606PP.  After a few days went by it was time to rivet the two halves of the rudder together.  I removed several clecos and some of the tape and put the trailing edge of the rudder over the back riveting plate on the workbench (photo at right above).

Trailing edge on back riveting plate Trailing edge complete

 

 I decided to alternate the direction that each rivet faced in order to minimize the possibility of the trailing edge warping.  This plan worked pretty well.  I was also as careful as I could be and tried not to put any rivet set marks in the trailing edge area.  I did pretty good right up until the last few rivets and then I got careless and put a few rivet set marks in the skin.  Damn!!! 

 

Close up of rivets Trailing edge is still fairly straight

Above left is a close up photo showing that I alternated the rivet direction.  Above right is a photo of the trailing edge after riveting.  I had some minor warping between rivets but all in all the trailing edge was fairly straight.

Leading edge after forming Enlarging holes to #30 (1/8")

 

Next on the agenda was the leading edge.  Above left is a picture I took after I formed the three leading edge sections.  I used a broom handle with the tape.  I formed the sections one at a time instead of trying to do all three at once.  Next I upsized the holes to #30 (above right).  I then riveted the leading edge with CR2414-4-2 Cherry Max rivets.  These are shear head rivets.  In other words, the rivet head is the size of a 3/32" rivet and the shank is 1/8".  I had dimpled these holes at the same time as I dimpled the rest of the holes in the skins.

 

Leading edge after riveting Corner primed for counter balance skin

Above left is a photo of the leading edge after all of the rivets were installed.  Above right is a photo showing that I primed the area where the R-913 counterbalance skin gets attached.  I did not install the skin yet because I need to install the counterbalance first.  The rudder kit did not contain a counterbalance weight.  I guess that they assume you will be using the one supplied with the original RV-7 rudder, however that rudder has been assembled for over three years and I do not intend to take it apart.