Sunday, May 6, 2012

Rudder Cables Installed

I began with time consuming electrical work this morning. It is simply amazing to me that it could take the amount of two hours to just install a switch. This is without support by the plans though. The switch in this case was the fuel pump switch I intend to put next to the throttle on the lower center panel. For the installation I needed to locate the fuel pump power supply wire - a work I had better done before final mounting all the harnesses. I was lucky in this case as the wire is a peculiar looking red wire. It's peculiar because it is thicker and stiffer than all the other wires. That way it was easy to trace it back to the Tunnel harness plug (with the help of the diagram again) and then to follow it under the panel base. That's where I cut the wire and installed spade connectors for the installation of the switch later on. With the help of a 12V power supply I also verified that I had indeed cut the correct wire, by hearing the unmistakable sound of the fuel pump when I injected 12V.

Then I soldered the DPST switch. One circuit is to connect the fuel pump to 12V supply, the other is to pull a yet to determine EMS pin to ground. This is to give Skyview the option of knowing in which position the fuel pump switch is and to show a warning if it is off. This should also be avoided by the cover I will put on the switch.

Joeri from the Netherlands had this great idea, and he hinted me to the pages in the installation manual to identify likely EMS pins I could hook-up the switch to. Please note that the pin has to be a female one. I used one from removing unused wires in the harnesses earlier on.

Coming back from lunch, I started working on inserting the rudder cables, so I could final install the plastic sleeves and the ground wires that were still waiting in that area to get connected to the airframe. I hope you can see that milky plastic tube resting on on e of the ribs. It has blue tape attached on the left side that kept it connected to the cable end during insertion.

When installing the cushioned clamps to hold the sleeve in place and also ground the ground wires, I noticed that the ground wire from the PTT switches on both sides were rather short. Too short for me, as the stick movement induced way to much movement in the ground wire as well as it was trying to compensate for its shortness.
They were ok in length when the tube was not installed, but the sleeve now forces the wires to bend 90 degrees and that takes the slack out of it. I opted for extending the wires on both sides by inserting a few inches with a splice. I also found the two ground point to be hopelessly overloaded with ring connectors. This made tightening them in that close quarter a real nightmare. I added a third ground point a few inches behind the left forward one by using the cushioned clamp in the middle of the left sleeve. I removed the primer in that area as well.

It was too windy for spraying paint outside of a paint booth, so I decided to end the day and cleaned up.
I will definitely install the elevator cables as well before starting on the gear legs. I pretty much want to be done as far as possible in the forward lower intestines of the plane before going horizontal with it again. That requires the cables to be installed, some more painting to be done on those little pieces that go aft of the rudder pedal tubes and the ELT antenna installation.

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