Tail Cone Stringer Dimples

I'm not sure, but THINK I may have made a mistake by dimpling ALL the holes of the tail cone stringers. I also dimpled the end holes mating up to the bulkhead frame where the fuselage will be attached later. I do not have the fuselage plans yet to read ahead to see if this will cause a problem. I want to start riveting today (Saturday) and since Van's help desk is closed, thought I'd reach out to brain trust for advice before I rivet it in and create an even bigger issue.

Here's my questions:
1. Should this hole have been dimpled?
2. If no, what is suggested fix / work around?

Here's a pic of the stringer with dimple. Bulkhead frame goes on top of dimple and tail cone side skin is on other side. I believe this is where the fuse skin will eventually sit on top of tail cone skin.

Good Morning,

10-16 Step 5 would indicate that you did the right thing and dimpled all the holes in the stringers. I think they have you hold off on dimpling the skins because you'll final drill them once you start the process of attaching the tailcone to the fuselage. That stringer dimple will find it's home when you final drill and dimple the skins.

No worries - build on.

No mistake. You know the external skin will be dimpled; so all thin mating parts will be dimpled too. I don't recall if the stringer or bulkhead is against the skin, but you can figure that out when you get the next kit. Don't rivet that hole now.

Thank you Eric and Bob! I felt like skin has to be dimpled at some point, so this gives me comfort to start the riveting today!!

Take a look at the EAA back riveting with a C-Frame Video. My tailcone riveting went quite well thanks to that video. And it makes for near perfect and pretty shop heads!

ERushing said:

Take a look at the EAA back riveting with a C-Frame Video. My tailcone riveting went quite well thanks to that video. And it makes for near perfect and pretty shop heads!

Click to expand...

Eric,
Good video. Very helpful and should make back riveting easy. Can you clarify one thing for me, were you able to do this with tail cone skins? Plans call for assembly prior to riveting. Were you able to rivet stringers onto skins prior to clecoing to the bulkhead and frames?

You can back-rivet the bottom and side skins. I started with the stringers, leaving the holes where they would attach to the bulkheads. Then I back-riveted the bulkheads to the bottom skin and, finally, each side skin. I got a helper to hold things in place when I did the bulkheads and side skins, which they found much easier than holding a bucking bar...

Edit: I should mention I did my back-riveting with gun and plate on a table, not using a C-frame.

I cleco'd the bulkheads in for stability and just raised the C-Frame and tailcone above the cleo height with some spare boards and plywood. I set the tailcone on it's side to rivet in the stringers. It's been a while but I don't think I was able to get every rivet that way but I was able to get the vast majority of them. It made most of the riveting a one person job and produced really nice results.

Thanks for the advice guys! Very useful!!

I did the backing plate on my workbench with carpet around it so I could cleko things from the inside and have the cleko ends sink into the carpet and keep things flush to the backing plate

This worked well for the stringers and side/bottom skins.

Link here that has a pic of my plate on bench setup that I copied From Ed.

https://adamsrv10.wordpress.com/2016/12/12/tailcone-progress/