Hrs: 14

The impossible rivet solution

I want to wait as long as possible with attaching the 3 rear fuselage top skins with rivets, you never know… This however leads to a problem because there is one rivet on each side that will be obscured when the rail-brackets of the sliding canopy are attached. This “impossible” rivet is to attach the front top skin to rib 1. After some thoughts a found a simple solution.

First of all thanks to Des for informing me about this problem and writing this in your blog.

Here is a photo of the hole where it’s impossible to rivet when the rail-brackets are in, even with my close quarters rivet tool:

It’s not in the manual but at the factory they dimple the bottom row. My idea is to use a #8 machine screw there, with a Philips 2 bit and a wrench it’s easy to insert the screw when the rail-brackets are in. To have sufficient space for the dimple in the skin I needed a thicker doubler that could be countersunk. After a few iterations this is the final design:

In Fusion360 I created the tool-paths:

The brackets were machined from 0.09″ thick 6061-T6 with my desktop cnc:

Next was dimpling and applying epoxy primer:

With solid rivets I permanently mounted the brackets to the airplane:

Inside view:

Next I made the dimples in the top skin; 1x #8 screw 100 degrees and 6x 1/8″ 120 degrees for the countersink rivets:

Test fit with the screw in place: