Sun Feb 27 2011

Fuel line tubing

After making a modification to the design to accomodate a swivel tee, I bent up trial #2.

This one fits great including the swivel tee. Here is a drawing.

Here's a close-up of the tee.

The last short piece to work on is the connection from the swivel tee to the bypass check valve. It's the simplest design so far.

With the long end connected to the swivel tee, I can see that the offset looks good, but somehow I ended up being about 3/16 inch too short.

Attempt #2 got me closer, but still too short. (How the heck did I manage that?!?!)

I decided a better approach would be to just leave the short end about a half inch too long and mark it in assembly. Because of the 180 degree bend, cutting this requires a mini tubing cutter (which I have). I suppose it could just be cut off with a band saw or hacksaw, too; but that seems a poor way to cut tubing.

Once again, the third time's the charm. There may be light at the end of the tunnel for this tubing work. Here is the drawing.

After getting some sleep (the previous images were taken early in the AM), I got a call from Dick Wetherald. Dick was about to go commit aviation and wanted to know if I would like to come along? Heck yeah! Dick picked me up in his really nice Cessna SkyHawk, N738BL, up at DLZ. I suggested we could go to Urbana for lunch. On the way, we flew right over Marysville, saw Joe Maynard's HiperLite out on the ramp, and decided to drop in. It turns out that Joe was moving from a shaded hangar to one that gets the sun. We also bumped into Clare Lutton. I had a brief chat with a fellow named John Popio. It turns out he knew a relative of mine, Rich Cencula, who lives in the area, is in his church, and used to be very active with Big Brothers and Big Sisters.

Next we headed over to Urbana for lunch. The restaurant was packed, but we got a seat...the food was good as usual. After topping off the tanks, we flew back to DLZ. Dick let me do most of the flying and even a couple radio calls.

When we got back to Delaware, we stopped over to see Joe Strausbaugh and George Mellon. Both were working on their planes. Joe had his panel apart to install a transponder, and George was working on his condition inspection. Last stop was over to Bob Leffler's hangar to check out the progress on his RV-10. It's looking great. He has the engine on and the plane on the gear. Today he happened to be working on his propeller spinner. Fun day...thanks for the flying, Dick!

Later in the evening, I decided to do a little more work. I had picked up eight new screws from Ace Hardware on my way home from the airport to replace the screws that shipped with my Andair fuel selector.

Here's why: The hex sockets in the original screws were not formed correctly. I stripped several out before I could get them completely tight. If you click on the image to see the full sized picture you can probably see what I mean.

Whereas, here is one of the new screws from Ace. Much cleaner hex socket. I changed out the eight screws holding the left and right ports on and tightened them down.

Andair provides a little relief adjacent to the edge of the screw head which allows you to peen the edge of the screw with a punch. This upsets the material and squishes a bit of it into the recess, thus preventing the screw from backing out. After doing this, I hope I never have to take these screws back out.

Here you can see the screws after peening.

I also went ahead and riveted the nutplates to the flanges of the valve.