Tag Archives: fabrication

Closing Up The Rudder

With a good rudder skin, I was able to prepare, fit and secure the skin to the structure. Using techniques that I’ve learned from building similar components, the rudder went together smoothly. It’s a fine result.

There are still several tasks remaining to complete the rudder – fit the skin for the aero counter-balance, mount the internal counter-balance weight, run the strobe wire, fit the strobe to the rudder tip, and then finally, finishing the fiberglass and mounting of the rudder tip.

The great people at TAF USA worked hard to support me and promptly get me a rudder skin that I was satisfied with. The one that came with my empennage kit wasn’t bent properly on the trailing edge. It simply did not fit happily on the structure. A second skin was unfortunately damaged from moving about inside the crate during shipping. The third one was the charm.

It is crucial that the skins are fabricated perfectly. This plays a huge part in the resulting components being true. Precise fabrication is a critical element of the pre-punched and bent parts that allows them to assemble into a component that is uniform and free of twists, even without the use of jigs. The design of Sling aircraft absolutely depends upon the accurate fabrication of the parts. If yours aren’t right, work with TAF to get ones that are. Don’t mess around.

VOR Antenna Mount Fabrication

Incorporating a VOR antenna keeps my options open. The antenna gets built permanently into the VS structure. I have to commit to the antenna choice now, but not the avionics. The Rami AV-520 happens to be an ideal size and has removable whiskers. If I eventually decide that I don’t want or truly need VOR/LOC/GS capability, the whiskers come off and the VS of the bird is clean.

Optimum mounting the antenna requires a little custom fabrication. A doubler plate must be positioned and the mating rib drilled for rivets. I ordered the doubler base-plate part number from TAF. The top VS rib gets modification to accommodate the whiskers and provide access to set-screws.

The fabrication process I undertook was a variation of what is described in the Empennage Construction Manual, pp. VS4. Eventually, small holes also need to be located and created in the VS skin to accommodate the whiskers and tool access to the set-screws. Careful positioning of the antenna base allowed me to minimize impacts to the VS top rib and the skin.

Rivet clearance areas need to be machined into the (hard plastic-like) antenna base. Several rivets also need to be shortened. The general process for rivet shortening is in the construction manual. There are places where space is tight and a bit of finesse helps to achieve good fit.