Left elevator (cont.)

With the stiffeners in place and the skeleton riveted together, it was time to bend the trailing edge.  This process is much easier the second time, as you're not as concerned about messing it up.  I made the bend with my wood bending brake, and the skin rests nicely on the skeleton with no clecos installed.  With the trailing edge finished, I was able to bend the tabs on the elevator for the trim tab opening.  After a little practice, I placed a wedge inside the skin with another wedge on top of the skin, clamped the whole assembly to the workbench, and made the first bend of the lower tab.  Then the top tab was bent, and the remaining rivets were squeezed. 

After trailing edge is bent, the skin rests on the front spar

Practice bend on piece of scrap aluminum

First tab bend (bottom) on elevator

Top and bottom bends finished - ready for rivets

Ready to squeeze perimeter rivets

Squeezing outboard rivets

Counterbalance weight attached

Left elevator main structure complete

Left and right elevators side by side for the first time - very cool !

Left elevator

The left elevator construction is virtually identical to the right elevator, with the exception of the trim tab.  While this seems like a small difference, I found that it took quite a bit more time than the right side, although I was very pleased with the results.  I started by deburring all of the skeleton parts and the skin, and removing the vinyl from the rivet lines on the skin.  There is a reinforcement plate that fits where the trim tab servo mounts that requires platenuts, to which the trim tab cover will attach.

Many people rebuild the trim tab several times, so I took that as a sign that practice was in order.  Bending the tabs on the inboard and outboard ends of the trim tab, as well as those on the trim tab opening of the elevator, are some of the more challenging tasks of the empennage construction.  I traced the trim tabs onto some scrap aluminum, cut them out, and clamped them to the wood blocks I fabricated for this task.  I learned how the aluminum responds to various bending techniques, including a low pressure rivet gun, and what I would need to do on the real tabs to make them turn out well.  My practice pieces got progressively better, and after the third one I made the bends on the real parts.  I think it turned out very well.

 

Deburring left elevator parts

Removed vinyl from left elevator skin

Ready for initial assembly

Skeleton coming together

Fitting trim access reinforcement plate

Platenuts installed on reinforcement plate

Skin match drilled to skeleton

Stiffeners match drilled to skin

Riveting skeleton together

Stiffeners riveted to skin

Right elevator (cont.)

Bending the trailing edge is a bit unnerving the first time you do it.  You've put in a significant amount of time into the stiffeners and skin at this point, and the last thing you want to do is mess it all up.  I constructed a bending brake from a set of 2x8s connected at the back with evenly spaced door hinges.  I clamped the brake to the table top, and placed a 1/8" dowel in the trailing edge to prevent over bending.  It's surprising how much force it takes to complete the bend.  I made the first bend with the trailing edge close to the hinges, then slowly moved it out on following bends.  Soon, the skin was open just enough to sit on top of the spar when the skeleton is placed in the skin. This method worked well.

Bending trailing edge

Bend complete - straight edge sits flush to point where radius begins

Just a few rivets left, and the right elevator will be finished

Right elevator complete - yeah baby!

Right elevator

After finishing the majority of the prep work on the rudder (cutting and deburring the stiffeners, match drilling the skin to the skeleton, and dimpling and priming the skin), I started working on the right elevator.  The skins on the rudder are only .016" think, so I wanted to back rivet the stiffeners on the elevators before attempting the same on the rudder skins.  This is probably an unnecessary step, but I thought the extra practice on the slightly thicker elevator skins would be useful.

Similar to the rudder, I started the right elevator by cutting and deburring all of the stiffeners for the top and bottom of the skin.  The notches Van's makes in the stiffener aluminum makes this a straightforward, albeit time consuming, process.  I also deburred the counterbalance skin and ribs, as well as the elevator spar.  After that, the stiffeners are match drilled to the top and bottom of the skin, the ribs are fluted, and everything is assembled and match drilled.

Stiffeners cut for top and bottom of skin

Assembling skeleton

Skin attached to skeleton and match drilled

Priming stiffeners

Stiffeners back riveted in place

Blue vinyl removed - I love how this looks!

Ready to bend trailing edge with bending brake

Rudder Time!

Things are progressing nicely now.  I started cutting and deburring all of the stiffeners for the left and right rudder skins, and then removed the vinyl from the rivet locations.  After that was finished, I started working on the skeleton.  A few pieces of aluminum need to be cut from scrap to be used as shims, but this is a straightforward process.  The counterbalance skin is then clecoed to the top ribs and everything is match drilled together.  It looks like the biggest challenge on the rudder will be riveting the trailing edge.

Stiffeners cut and deburred on right side skin

Removing the blue stuff

Both skins match drilled and ready to go

Drilling R-918 bottom attach strips to R-904 rib

Skeleton ready for disassembly, dimpling and priming

Vertical Stabilizer work

Compared to the horizontal stabilizer, the vertical stabilizer seems to come together very quickly.  It's probably a combination of getting used to working with aluminum and understanding the plans better - it's nice to see things take shape more rapidly. 

Match drilled skin to skeleton

Priming internal components

Skeleton primed and ready for riveting

Riveting spar doubler and hinge brackets to rear spar

Riveting skeleton together

Final assembly

Finished Horizontal Stabilizer

With the nose rib riveted to the horizontal stabilizer skin, things move along pretty quickly.  Jim and I riveted the internal section of the skeleton, which went really well.  With that completed, I was able to squeeze the perimeter rivets with my hand squeezer.  It's cool to see the first section of the empennage finally complete.

External view of nose rib rivets

Early internal view

Riveting bottom left skin
 

All internal rivets complete

Horizontal stabilizer finished - very cool !

Proud owner of a completed horizontal stabilizer.