Sun Apr 16 2023

Joggling rear window retaining strips

Before painting the interior of the fuselage, I need to finish the rear window retention strips and get them drilled to the turtledeck skin. That means I need to check the window thickness at every joggle tab location. I used a 0-1 micrometer to check the thickness of the rear window where every joggle will be.

I marked every tab with the required joggle offset. I'm actually going to add .010 clearance everywhere so the fit isn't too tight.

Both joggle strips marked with each tabs' offset. Joggle tooling is shown here with for the four different sized tabs.

Here is how the strip clamps up in the tooling. Each tab is clamped up independently. the joggle offset will accomodate .177 window thickness (the .010 clearance mentioned previously will result in a .187 joggle). Lesser offsets can be formed by adding shims to prevent the steel block (lower left corner) from being pushed down quite as far.

The arbor press pushes the steel block down to form both bends of the joggle simultaneously.

Here are the first few joggles. There are 35 of these on each strip, so it takes a while to do all of them...especially since each setup needs to have the offset shimmed to match the requirement.