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