I decided to follow the advice of other builders to use 3/8 aluminum fuel lines inside the fuselage. The provided rubber fuel hoses need to be replaced every 5 years and I guess the task of doing this is not fun and you will spill fuel in the cabin. While working on the center fuselage is a good stage to create and install the fuel lines. At a later stage it might be difficult to insert the fuel lines. Because of the limited space in the center channel and the need of an exact position for the fuel valve to be connected to the aluminum fuel lines, it’s a good idea to order an extension kit from Andair. You can cut the extension to the needed length at a later stage when you mount the center console.
In order to connect the aluminum fuel lines to the Andair fuel selector valve you need to change some fittings and other details. Here is a list of things I had to order from Andair (http://www.andair.co.uk) and others. The project is ongoing, so the numbers are subject to change!
- Andair Check Valve CK375-M with “Male (AN-6,JIC-6)” on both ends.
- 4 x 90° Elbow Fitting “Andair EF20”.
- Andair Extension Kit Valve Model FS20-2 with a 12inch extension & Universal Joint:
- For the top two NPT fittings I already had two 90° AN-6 to 1/4″ NPT adaptors :
- 4 x AN-6 Bulkhead Connectors:
- 2 x AN-6 to 1/8″ NPT adaptor for the booster fuel pump:
- 40ft 3/8″ 3003-0 Aluminum tubing from Spruce (Versatube)
- 20 AN-6 Flare Nuts with sleeves:
The flaring tool for the AN6 fittings needs to be 37° and NOT 45°. I would recommend to not buying the $20 version of that tool. The “Tube Straightening Tool” is also highly recommended. The tube cutter creates nice clean cuts. If you have never done a flared fitting, here is a nice video on how to do it: How to Flare Aluminum Tubing for your Experimental Aircraft
I need to make some fasteners for the fuel lines so that the lines do not touch any metal and do not move around.
Here they are, 3D printed spacers for two 3/8″ fuel lines with a hole for M4 screws. I would recommend to use PETG with a melting point of about 260°C or something similar temperature resistant for the print.