String Theory

Today I got the rest of the GTN650 mounting bracket done and clecoed into place on the panel. After that, I turned to fabricating a shelf for the remote LRUs of the G3X system. LRU is line replaceable unit, which basically means it is an electronics box that can be mounted separately from the screens on the panel. This gives flexibility, but also means I have to think through the best ways to organize them and where they should be mounted. In my installation, I will place these components on an avionics shelf forward of my instrument panel.


I made a mock up of the shelf that I will eventually build in order to use it for planning. This will also give me something to give to the folks at SteinAir so that they can wire everything up in the right relative positions. I started with a cardboard template to get the general idea. Then made one out of plywood. I plan to make the final one out of fiberglass, but I don’t have enough time to make the final shelf before our meeting tomorrow. Plus if I make the final shelf after everything is wired, I can be more flexible with any changes SteinAir makes.


Once the shelf was made, I started mapping out wiring paths to and from all of the components that will interface with the G3X Touch avionics system. To do this, I ran string, taping it in place, along these paths. This will give me something to measure to determine wire length. To these string lengths, I will add service loops and some percentage extra. Some of the wires will be able to be trimmed to length after they are constructed, some will have connectors on both ends. The wire paths I laid out were from the instrument panel to each of the following: engine monitor module, autopilot roll servo, fuel quantity probes, master solenoid, pilot stick grip, co pilot stick grip, magnetometer, back up battery, intercom jacks, and 12 volt receptacles. All the other devices will be on the avionics shelf, so I don’t need to measure those.


Tomorrow, Greg is coming over. I will get his input on wiring paths and see if he sees anything I have overlooked. We will make any appropriate changes, and then measure the strings. Ill give you the update tomorrow on our meeting with SteinAir.


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