Elevator trim tab fitting problem

As I start to fit the trim skin and piano hinge together, I immeidately ran into several problems.

Problem

• Piano hinge rivet holes do not align with trim tab skin
• Trim Channel shape does not match skin bend

Shape problem

First off, the KAI had no mention of the parts I received (EL-SKN-103-C-E-2 and EL-CHL-008-X-F-0). Instead, the instruction is based on EL-SKN-103-C-E-1 which based on my research is a single piece that fully forms a trim tab.

So based on the shape of the parts and using some imagination, I think I needed to mate EL-SKN-103-C-E-2 and EL-CHL-008-X-F-0 which essentially becomes the same shape as EL-SKN-103-C-E-1. And I need to insert the piano hinge between the skin and top channel.

As I mate the channel and skin, the formed bend on channel does not really comform with the shape of the skin. If I cleco the top skin with the channel there is a huge gap between bottom skin and channel, and vice versa if I cleco bottom skin.

I do not have a bending brake (ordered one from harbor frieght), so I tried to hand bend the channel. It helped to some degree. I was able to reduce the gap significantly. I sent Sling technical an email but I assume they will tell me to keep bending.

Here is the effect after some bending:

Rivet hole alignment

The bigger problem is the rivet hole alignment between the piano channel and the skin/channel.

When I insert the piano hinge between the channel and skin, many holes do not line up 😫

There are 28 holes on the hinge that are supposed to mate with the trim skin. Only 12 of them are aligned. The rest all have some kind of misalignment, some as big as 1/3-1/2 size of a full rivet hole.

I’m not sure what’s going on with the pre-drilled holes. but I’m not willing to just ream them out. I will end up with several huge oval holes if I do that.

In any case, I sent a question to Sling technical. I really hope there is a solution without replacing parts.

Here are some misaligned holes:

Conclusion

For now, I am not able to wrap up the trim piece . But I think the rest of the elevator is in a good shape. I will start to rivet the main elevator component and leave the trim aside until I hear back from Sling.