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Mounting The Empennage

February 15th, 2010 Leave a comment Go to comments

Mounting empennage.I reached the point in the canopy construction where it says to start cutting the actual plexiglass.  Given that it’s the middle of winter and the temps in the basement are only in the 50′s, I decided to postpone further canopy work and move on to the fitting on the empennage.  Everything fit with no surprises.  The digital level and tape measure assured everything was lined up properly and had the proper travel.

Another view of the rudder stop from the bottom, looking up. In the background you can see the front spar of the rudder and the three extra rivets I added to account for the minimum edge distance after the front spar was shortened by 5/8“, per the plans.

Instead of the exterior rudder stops made from AL angle, I installed this internal stop made from Delrin.  I bought it quite a while ago from Jeff Bordelon.  I’m not sure if he still sells them.  Right is a view of the rudder stop from the bottom, looking up.  In the background you can see the front spar of the rudder and the three extra rivets I added to account for the minimum edge distance after the front spar was shortened by 5/8“, per the plans.

I was able to dimple these #30 holes in the trailing edge of the rudder by using a standard dimple die, paired with a pop rivet dimple die, a little hardwood wedge, and a couple taps from the sledge hammer. The results are almost as good as those done with a rivet squeezer.While fitting the fiberglass tips to the elevators, I had to dimple the outboard edges.  The dimples at the trailing edge are tough because its so narrow in that area.  I was able to do a decent job by using a normal dimple die, paired with a pop-rivet die, a hardwood wedge & small sledge hammer.  This worked well enough, but when it came time to pull the rivets in those same holes, it was too crowed to even insert the rivet after the opposite one had been set.  So I ended up just filling that hole with proseal.

I began closing the backside of the three stabilizer fairings by epoxying a cardboard rib across the opening. These dried while attached to the plane so they would be holding the right shape. The VS rib in particular was crooked until I put some braces on each side and a shim the left.

I used an epoxy soaked cardboard rib to hold the shape of forward fiberglass tips.  The vertical stabilizer tip didn’t really match the profile of the rudder until I shimmed it a little and let the rib cure in place.

After the cardboard rib dried, I dressed up the ends by adding some carbon fiber. The sockets inside just held them down as things dried overnight.Then I thought I would be fancy and add some carbon fiber over the end to dress it up.  I would leave the  end unpainted and it would just be cool to look at — just like any else carbon fiber!  The tips are shown here curing with a layer of fiberglass and a layer of carbon fiber.  They didn’t turn out exactly perfect and I ended up filling the imperfections with microballons and gray primer.  If I were to do it again, I would get some samples from DragonPlate and use those.

I made the rod end bearing tool on the left for the smaller REB's. It's made from a 1/2" piece of PVC and a coupling. The one on the right is for the larger REB's and is made from a modified 3/4" socket.Finally, while fitting the enpennage control surfaces, I had to adjust the rod end bearings to the correct depth.  I still had a modified socket from  the RV-8 that I could use on the one larger REB on on the bottom of the rudder, but it didn’t work on the remaining smaller REB’s.  So following Sam’s lead, I made another one from some spare PVC.  Works great!

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