When installing the side skins and reinforcement ribs 5, I didn’t pay attention enough to the orientation of the flanges of rib 5 in relation with the flanges of the main gear mounting box. The result is a different orientation at the front and the rear. Furthermore a 4 mm hole is exactly under the head of the bolt and nut of the main landing gear, that made installing a 4 mm rivet impossible. 4 shims were designed to solve these issues.
Here are the issues visible:
- at the front the flange of the main gear mounting box is above the flange of rib 5
- at the rear the other way around
- insufficient space to install a 4 mm rivet
To solve the orientation mismatch of the flanges, tapered shims were needed.
And to solve the issue with the rivet hole 2 additional holes of 3.3 mm were added next to the hole under the heat/nut. The hole in the shim that is aligned with the 4 mm hole was designed with a diameter of 3.3 mm as well so that a 3.2 mm rivet will fit in the 4 mm hole.
A few design iterations and machining prototypes were needed to end up with this final design:
A drill template was made to drill the additional holes:
The shims after machining and priming:
The shims were glued in place with Scotch-Weld 2216:
Ready :
