Lancaster at the Nova Scotia Aviation Museum at Greenwood, large bugger isn’t it?

Self portrait in flight over Lake Austin

Stability and handling are good… V_Max is about 3 knots. Didn’t manage to hit V₁ so actual flight still eludes me. Guess I’ll have to order the wings!

Here is the servo on it’s mounting plate, you’ll notice that the leads are a little short to reach the cockpit at this point.

The first part is to extend the leads on the servo so that they have enough length to reach through the HS and make it to a connector I will mount in the tail of the fuselage.

For people not familiar with wiring, here’s a brief tutorial… first I figure out how long the wiring need to be to reach from the servo’s mounting position into the fuselage through the HS, I leave it a little longer than I estimate, just in case. Then I cut some of the appropriate size wire for the amount of current that will be on the wire and for the length of the total cable run. For the trim servo it’s not much current on two leads that operate the motor and the other three leads are for position signalling and have even less current so the guage [wire is sized in ‘guage’ or AWG] of the wire doesn’t have to be much. I’ve selected 22 AWG for this application.

Also note that the wire is white… that means that I have to put tags on each lead so I can tell them apart later in the wiring harness. Not much problem now but later on I’ll have hundreds of wires and tracing them out if they were unlabelled would be a major pain. The wire is white because it has insulation sheathing made of Teflon. Ordinary plastic wire isn’t allowed in aircraft since the plastic burns and produces toxic fumes in a fire or a short. Don’t wan’t to add that to any potential in flight emergency.

Next all the wires are stripped to expose the conductor, the and each extension are twisted together neatly. Solder is applied to make a good solid mechanical and electrical connection. After each wire is soldered heat shrink tubing is slipped over and shrunk with the heat gun to insulate the connection. Finally all of the wires are fed into a larger piece of heat shrink tubing to gather them into a neat bundle and they are fed through the grommets in the elevator.

Here is the servo installed in the bottom of the left elevator. One remaining task is to fit a small fairing over the pushrod. Every little bit of drag reduction and streamlining makes the plane go faster and saves fuel!

The builders manual, especially the manual from Van’s, has detailed, step by step instructions and a lot of helpful advice. Everything one needs to successfully complete the project.

First thing you make a fixture out of wood, a simple V notch to pin the end of the trim tab in place with the portions to be folded protruding.

Next with the ends to be folded securely pinned in place in the jig the protruding ‘ears’ are bent. They can be hammered, but that makes for a kind of ‘beaten’ over crummy look. I prefer to use a heavy weight to gently pressure them into shape. I have a 4″ diamater by 1 foot long piece of cold rolled steel rod that makes a great, though very heavy folding tool.

Here’s the end result, a neat smooth fold.

And finally I can match drill, and fit the trim tab in place.

Here’s a great video I found of a Van’s RV-7A on an evening flight in Sweeden. Teriffic video and makes me very nostalgic for my evening flights in El Gato. With any luck I’ll be flying again in a few years as El Gato Dos gets built and flying. My thanks to the pilot of SE-XLL who posted the video on youtube.

You can see the rolled edge ready to river together in the above picture. In the next photo you can see the opening in the botom of the elevator where the trim servo will mount and the notch in the trailing edge is where the trim tab will fit. More on this when I start bending the trim tab and fitting the servo.

Below is a picture of the tip drilled into place on the horizontal stabilizer. At the moment it’s simply drilled and held with 3/32 clecos and is open on the back side.

In the following steps I’ll be setting it up to be attached with #6 stainless screws and closing up the open back side for drag reduction and to keep anyting from nesting in there when the plane is hangered. Since the open end doesn’t hold the tip to the shape of the opening we’ll have to create a support to allow it to keep it’s shape when removed. Below you can see a small former that I’ve made with fiberglass and place in the open end to cure after the tip has been cut to fit.

After this cures I’ll remove the tip and add fiberglass to cover the entire opening then sand the tip to have a nice streamlined shape. Below is the tip removed and I’m laying fiberglass cloth with resin into the open end to close it.

The resin I use is a West epoxy resin, it is available with mixing pumps that meter the resin and catalyst in proper ratio for mixing.

After the fiberglass sets it requires a lot of filing and sanding to create a nice smooth finish. Below is one tip in progress after one application of filler and a bit of sanding. Lots of fill and sand operations to go yet until this is finished.

Repairing can mean simply buying new parts and building that section over again or sometimes it means a repair. The proper means to repair aircraft are documented in a publication of the Federal Aviation Administration (FAA) entitled; Aircraft Inspection, Repair & Alterations: Acceptable Methods, Techniques, and Practices, publication AC 43.13.

My current goof wasn’t a bad one, it was just ulgy work and I decided that the cosmetic flaw didn’t belong on my airplane. In the photo below you can see two small tabs that need to be bent over by hammering them over the wooden form to overlap and make the inner edge of the trim tab on the left elevator.

In forming the bend I scratched the metal and the bend wasn’t crisp or well done. So I elected to fix this by first removing the tabs and making a rib to fit into the end in their place. Below are photos of the trimming and finishing of the tabs and of the rib I made to fit. More pictures and descriptions later as I make the final fitting and drill it.

Here is the rib I made to take the place of the tabs.