Fuel supply line route

[LettersFromFlyoverCountry]

I have studied the drawing and ran the first fuel supplyline from the fuel valve area around the landing gear and out the side of the fuselage. The drawing suggests an "S" curve in the tubing as it comes through the landing gear weldment (on a 7A) and then up and out the fuselage.

I initially ran the line through the bottom hole in the weldment but then thought that resulted in a pretty tight curve, so I backed off and ran through the middle holes in the weldment instead. This way, I got a gentle curve from the landing gear to near the exit hole, and then a 90 degree bend to go out.

I'm not sure this was the usual route because I didn't need to do that much bending around the weldment. Am I missing something.

Here's the initial route.

And then ...

As you can see, the tubing is exiting the hole in the landing gear weldment on a more gentle curve.

And then a near-90 degree bend and then out. Now I think if I went to the bottom hole, I would need a tight bend to come up to exit the fuselage. I can do that, of course, although I'm trying to do this without taking the landing gear weldment out since it's already torqued down, and it's a lot easier to work with the spring benders (which worked fine here) then the Imperial bender in this tough-to-get-at-location.

Also, if I went down to the bottom hole, I've created a low spot, since the tubing has to then come back up to get through the appropriate (i.e. bottom) hole of the outboard cover rib.
Is this acceptab;e?

 

[Build9A]

you got it

Your installation looks good. I say the path of least resistance. I bought lots of tubing from Vans in order to redo this area. My only suggestion is to make sure that the tubing will not chaf on the gear weldment. Maybe some protection for it where it goes through the hole. However, it looks like you have pretty good clearance. You did alot better than I did. Good job. Jack

 

[LettersFromFlyoverCountry]

My only suggestion is to make sure that the tubing will not chaf on the gear weldment. Maybe some protection for it where it goes through the hole.

I'm going to put a small bend inboard just before it passes through the hole to have it centered. Seems like it might be a good spot to fit a grommet too.

 

[robertahegy]

That looks good, Bob. Ace hardware usually has a nice selection of rubber grommets. I wound up using hose, but I like your route better.

Roberta

 

[Finley Atherton]

Bob, I just installed the fuel lines yesterday (before your post) and did the same as you. After reading various horror stories about getting the line through the weldment I was expecting the worst. I used a spring tube bender and it took about 10 minutes to do each one. In fact the fiddliest bit was installing the two rubber grommets in the sidewall. Maybe Vans has modified the weldment. Mine has 4 lightening holes in this area.
Finley Atherton
9A Fuse
Australia
Beautiful WARM weather in the better half of the world!

 

[tclaire]

Can you run a flexable type gas line in this area

 

[LettersFromFlyoverCountry]

Bob, I just installed the fuel lines yesterday (before your post) and did the same as you. After reading various horror stories about getting the line through the weldment I was expecting the worst. I used a spring tube bender and it took about 10 minutes to do each one. In fact the fiddliest bit was installing the two rubber grommets in the sidewall. Maybe Vans has modified the weldment. Mine has 4 lightening holes in this area.
Finley Atherton

It went so fast I figured I must've done something wrong. Had time left over to watch the second half of the Vikings game -- which was unfortunate. Now I gotta figure how to get that control rod installed to the bellcrank.

+5 here today but anytime I can get something on the plane done I feel like I've cheated the weather gods.

 

[Radomir]

I followed the steps Walter Tondu did on his and it was easy and quick. I also ran it through the middle hole in the gear weldment..

PS. Whoever suggested to use that Aeroquip elbow on the facet pump -- THANK YOU! It was an awesome idea.

 

[Alschief]

Your welcome, they worked for me also.

Regards

AL Smith
KEOS
RV6 FIrewall Forward andNew Panel
N495AB Reserved

 

[Jim Percy]

Bob-

I've got an idea why yours went more easily than mine, and probably others. Check out the position of the holes in my 3-hole bracket vs. yours. I had to make an IMMEDIATE bend to clear the landing gear leg, and getting it just right took a couple of tries. It looks like your holes are far enough aft that you were able to go straight through. Don't know if yours were pre-drilled, mine were (QB).

I'm jealous-
Jim

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[LettersFromFlyoverCountry]

Bob-

Don't know if yours were pre-drilled, mine were (QB).

I'm jealous-
Jim

Hmm...I think I had to drill them myself, but last spring was too long ago for me to remember.

BTW, I did finally get the control column to to bellcrank rod put in afterward (yeah, I know, I mixing threads). I have a VERY slight chafing on the road at the 705 pass-through. Anyone have any suggestions on how much to trim out (gonna be a tight squeeze 'cause I don't want to take that tube out.

 

[andyrv]

Control rod

Bob,

Take a look at Dan's pictures on the control rod. Slides in easily with no bending.

Andy

 

[andyrv]

Control Rod

Here's the link:

http://www.rvproject.com/20030508.html



Bob,

Take a look at Dan's pictures on the control rod. Slides in easily with no bending.

Andy

 

[LettersFromFlyoverCountry]

I didn't need to bend it, but "easily" isn't a word I'd use either. . The strictly diagonal approach didn't work for me. I ended going diagonal and then prying the 707 bottom slightly to allow the male rod end to slip into the conduit hole which gave me a little more room and then allowed me to bring it forward and get it into the passthrough on the 705 with a slight flexing.

I then installed the rod end bearings and attached it to the control column and then installed the bellcrank and then attached the rod end bearing to the bellcrank and tested. (by the way, the washer wrenches are rapidly becoming my favorite tool). I had previously adjusted the rod ends so (a) at least half the threads were engaged on both ends and (b) was to the lengths called out in the plans, then marked the location of the jam nut on the threads before removing the rod end bearing.

Upon testing, I heard the slight chafing (just enough to slightly scrape the primer. I rotated the rod to be sure it wasn't the result of a bend and it did not appear to be the case.

So I'll probably try to get in under there with a dremel to give me a little more clearance.

ONe thing I noticed reading Walter Tondu's site was his notation that the rod end bearing was hitting the top of the clevis on the control rod and he wasn't getting his elevators to full stop. Never did find how he resolved that or if it was a problem with a pushrod length or what. He was in the neutral position and the bellcrank was straight up and down, so I have to check with him and find out what the result was. Obviously, I haven't installed the elevator pushrod yet. That's another deal that'll wait for spring, I guess.

I'm sorta just bouncing around doing little odds and ends until spring. Fuel vent line, fuel line, landing gear, pushrods. Not sure what I'll do next. I'd like to figure out wiring runs, but I'm thinking of waiting until after the SportAir workshop in OSH and until I've got a fully diagrammed electrical system.

Maybe it's time to order the Airflow fuel pump and get going on that.

 

[Gary Wilcox]

Fuel line

Bob,
I noticed where your fuel line exits the fuse it goes through a grommet. I beleive there shoud be two grommets, one on the outer skin and one on the doubler. The second grommet is a tight fit but will fit.
Gary

 

[Davepar]

I only used a grommet in the side skin. Why would you also need one in the doubler?

 

[jimpleasants]

Is there a viable alternate routing? It appears that a 90 elbow out of the tank would go to a straight shot through side skin, the gear mount, and the support brackets. It seems that there is adequate space between the tank and the fuselage side. A curve around the fuel sensor plate would be easier than the "two right angles. Has anyone done this?

Jim

 

[Jekyll]

Groan

Tonight was fuel line night, or should I say FOOL line. I have a nice pile of shredded 3/8 tubing. I wonder what aluminum goes for in the recycling market! I tried going around the front of the 7A gear weldment (they are torqued in). It went swimmingly until I tried to slide the snap bushings in place.

LESSON LEARNED: The snap bushing won't slide in to place with the tubing through them. Yup, had to take the it back out and put the bushings in first. This would work with grommets instead of snap bushings.

I think I'll try a hallucinegentic (sp) tonight. Maybe I'll have a peyote induced vision to lead me down the golden path.

Had to stop to unwind.

I guess I'll take out the weldment tomorrow, another several hours wasted. What a pain these lines are.

Jekyll

 

[Gary Wilcox]

fuel line

After many frusterating attemps at running the fuel lineson my 7A, it was decided to use teflon, steel braided flexible hose. Quick easy and very accomadating of tight spaces. I drilled one hole in the support bracket beside the fuel valve and in it went, fittings and all, miserable job made easy.
Gary

 

[Jekyll]

I hallucinated last night and today decided to take the gear weldment off and see if that would work better. Wrong, when running the line through the bottom hole on the removeable braket, you can't get to the screw to reinstall it. Can't put the weldment on with the bracket installed.

Started from scratch (now further behind than when I started the line last night because I needed to reinstall the weldment). I ran the line around the front of the weldment and it only took 15 minutes. This time I had help pushing the line through as I worked the curves around the weldment. It worked great! In fact, most of the 15 minutes was spent adjusting the 90 degree bend to fit the valve input fitting.

I'll post some pictures shortly.

Jekyll

 

[N941WR]

has any body done this with the wing s on the acft.?

Yes, I did. But then my -9 is a tail dragger and I don't have those pesky gear weldments in there.

The only thing to remember when running those lines, is you are not supposed to run fuel lines above any type of wiring. Something about dripping fuel on energized wires. I don't understand what the issue is.

(Note, I didn't see anyone running wires under their fuel lines in any of these pictures, it was just information for new builders.)

I have seen pictures of people using bulkhead fittings in the bracket just before the fuel valve and a 90 degree bulkhead fitting exiting the side of the aircraft. Using those fittings would sure make running that line through the gear weldments much easier, IMHO. It would also make fitting a short tubing between the side of the aircraft and the fuel tank a LOT easier.

Ditto for me on Radomir?s comment:

PS. Whoever suggested to use that Aeroquip elbow on the facet pump -- THANK YOU! It was an awesome idea.

 

[IowaRV9Dreamer]

fuel & vent line grommets - how many in side skin?

I finally ran the fuel lines from the valve out the side skins, through the gear weldments. Using the methods on this site it was very easy, maybe 20 minutes each side. I'll draw up what I did and post for others following.

My question involves the grommets that Vans supplies. They give you two 1/4" grommets and four 3/8" grommets.

The 1/4" grommets are for the vent line - I put them in the doubler (not in the side skin). Of course the doubler & side skin are very close so I think that is OK.

The 3/8" grommets are for the fuel line. On each side, I put one in the gear weldment, and one in the doubler.

Does this sound OK? The plans call for a single grommet on each line, and don't specify if it goes on the skin or the doubler. They don't call for any on the weldment, but I sure think it needs one.

I can add another grommet to the side skin, but I don't see what it will actually do. It would be a very tight fit against the doubler grommet.

Now just the brake lines remain... and those look easy (uh-oh, now I said it )