gratechef

I am installing a Fuel Dot & Switch on the side of my Big Stik 60 and have a question...

Adding a 3rd line for refueling in the nose of the fuel stopper requires that I then route the fuel line back through the fire wall to about the middle area of the fuselage where I am side mounting the dot & switch. Looks to me like I could simply tap into the back of the fuel tank which would be much closer, simpler and cleaner. It would also reduce clutter around the already crowded engine compartment. The only concern, of course, is the tank possibly leaking at the tap.

Has anyone ever successfully added the 3rd refueling line in this manner?

Flyin Beagle

My Feedback: (1)

I dont know how you would ever get the new hole sealed. I would just do it the old fashioned way and locate the fuel dot closer to the front of the plane.

MinnFlyer

My Feedback: (4)

There is no point in adding a 3rd line on a Stik.

The 3rd line is for a cowled engine where you don't have access to the carb line.

On a Stik, you can just use the carb line. Otherwise, you're just making a simple thing more difficult.

gratechef

Thanks much for the feedback.

Maybe I have fat fingers but fueling by way of removing the line from the carb is a real pain. Also, I have a filter on the line going to the carb so adding a "T" is complicated.

Another motivating factor is that the nose gear rod runs down the middle of the engine mount which is right in front of the fuel tank stopper. So working three lines around that rod is a real challenge.

It is what it is... just seems ashamed that the back end of the tank is exposed and clear; it would be very easy to tap for the refueling/defueling line.

MinnFlyer

My Feedback: (4)

If you have a fuel filter, just unplug the line between the tank and the filter and fill there

gratechef

Truth is, I'm jealous of those guys who use those nifty fuel dots on the side of their planes. I am looking for an alternative to pulling fuel lines on & off.

Gray Beard

My Feedback: (-1)

-pkh-

My Feedback: (2)

That's exactly what I do. In fact the main reason I put the filter on the carb line is to give me a convenient location to access the fuel line for filling. The filtering is just a bonus for me!

MinnFlyer

My Feedback: (4)

Don't fall into the trap of doing something complicated because it's cool. I can't tell you how many times I've done that only to waste countless hours UN-doing it later.

heritageman

My Feedback: (4)

This is the way I fill my cessna tank.

Scar

My Feedback: (3)

I'm interested. I would NEVER do this on a plane, at least the first time, but if it worked there would be many interested.

For your experiment, put your engine on an engine stand. Make your hole in the tank and insert a bulkhead connector (available from DuBro and several other sources.) Use an appropriate O-ring inside for a seal, and add an appropriate seal on the outside to provide support and prevent aggravation of the stress riser. (The hole is a serious stress focusing point, making it easy for any vibration to cause a crack to propagate from the crack.) Mount the tank on the stand to feed the engine.

Run with a mildly unbalanced prop ('most any from the factory), and watch for leaks. If the system doesn't develop a leak after a few hours (let's say, 10 tanks) on the test stand... risk it in a plane. Fuelproof the area in the plane beforehand, in case of leaks. You'll want to monitor the location faithfully for many flights, in case of leak.

I don't expect the delicate tank to survive long after introduction of the stress riser, but I could be wrong.

Good luck,
Dave Olson

gratechef

Wow, this sounds like one of those stories where everybody just says "Well this is the way it's always been done..., so join the misery."

Why doesn't Dubro or someone come out with a fuel tank with a nipple on the back of the bottle for refueling/defueling access? Then a fuel dot could be mounted to the side of the plane for easy access. No pulling off fuel lines, etc.

Look how roomy the back of the fuel tank is......

da Rock

Keep in mind that just drilling a hole in a plastic tank isn't going to hack it.

I don't know of any hardware available right now to "tap" a tank reliably.

Do you have something in mind to do that?

gratechef

Just an IDEA at this point; do not know if it can be done successfully.

Was thinking with all theveteransand creativemodelershere that SOMEONE would have considered this solution. Why have all of your hoses crammed up front when the back of the bottle is wide open?

The ideal solution would be a factory bottle from Dubro or other with a built-in nipple (molded into the plastic bottle) on the back to plug in a fuel line. And it would be especially nice if the inlet inside the bottle was at the bottom for defueling.

As for a homemade version, with all of the high-tech fuelresistantadhesives & sealantsavailable today, it seemsplausiblethat this concept could work. My thoughts were to drill a hole in the back of the tank, seat a rubbergrommet in the hole, insert a tight fitting metal tube (curbed to the bottom inside) and then apply a really good fuelresistantsealant around the area.

Again, I have no idea if this concept will work so I was hoping someone with experience could help. Or offer a work around/better solution.

Thanks!

MinnFlyer

My Feedback: (4)

Because it's a really bad idea and totally unnecessary.

If you had a cowl, the line can come out the front of the tank and terminate on the wall of the cowl.

If you don't have a cowl, a fuel dot is not needed.

A tap at the rear or side of the tank is just begging to leak inside the plane.

As I said, Fuel dots are for cowled engines. You just want something that is not necessary - so you are having to jump through all kinds of hoops to get it.

ArcticCatRider

My Feedback: (6)

I say drill two holes in the tank, then run lines to fuel dots in the top of the wings...like a real overwing fueling station. Then have an RC tankwagon full of fuel pull up alongside the plane to fill up.

But in all seriousness, if you do drill a hole in the tank, reinforce the area first. Think of a balloon....it you stick a needle in it, it'll blow. But if you put a piece of electrical tape on it, then put a needle through it..it will hold together. Maybe roughen the surface of the tank, then use some fiberglass cloth and 3 hour epoxy. The slow cure epoxies tend to be more flexible. Also, in your set up..make sure you can drain the tank throught the dot...not just fill it.

There's really only one way to find out....

da Rock

And if you do drill a hole or two in the tank, good luck with engine runs and leaks from then on.

Nobody drills holes in plastic tanks because they really don't work well with holes in 'em that can't be made leak proof. But good thing about our hobby is we can try anything we can think of and the pilot never dies during testing. Some of 'em wish they'd never been born, but seldom die of it.

The first thing you need to work out is leak proofing your new outlet. If you can find any hardware that's sold for the task, come on back and let everyone know about it. It'll be interesting to see something that might work. And you should get advice on it's suitability or info that'll save you some time.

RCKen

My Feedback: (9)

While you may have lots of room behind the tank in THISplane, many planes do not have room behind the tank. As has been said before above, this just isn't a good idea. The reason nobody has done this before is it's simply not something worth doing. Trust me, if there were merit from having a fuel tap on the back of the tank Dubro would be selling one like that. As others have said, you can drill a hole in the tank and try to run a line through it. As others have said, it's going to be a weak point in the tank and will probably cause the tank to crack and fail. As others have said, you will have problems getting the tank to seal properly, which will result in fuel in the compartment with is not good for the wood and glue joints in the plane.

If you insist on having the fuel dot in the plane then do as you indicated in your first post, run a line and come around the side of the tank to reach your fuel dot. There is no harm in doing this and won't affect how anything works.I've done it before in several planes and it works fine.

Or, if you dead set on having a tap on the backside of that thank, pull the tank out and turn it around and install it with the bung in the rear of the compartment.

Ken

gratechef

Okee dokee then. It was just an idea, albeit a poor one as I have learned.

Preciate the feedback & saving me the troubles.

Lnewqban

If you still want to experiment, look for part S476 at this webpage:

http://www.sullivanproducts.com/Fuel...sMainFrame.htm

Or buy from Tower Hobbies:

http://www3.towerhobbies.com/cgi-bin...&I=LXBWL5&P=RF

As explained above, reinforcing the hole is as good idea as using some thread locking means.

robbinsp

My Feedback: (10)

yo chef, just do what you think would be nice. its your hobby, do it your way. i think it will work. do u know that guys are making their own fuel tanks on big gassers out of pop bottles because of reliability issues! check out flyinggiants.com, well help u there! adios amigo, and to those who are naysaers, I say Pi$$ on flying in circles... and you know what i mean!

robbinsp

My Feedback: (10)

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Lnewqban

All the previous advice is good, because it comes from years of experience dealing with fuel and air leaks.

Doing an additional perforation is introducing an additional point of potential trouble.

Now that you are aware of the negative issues, it is your choice going thru the trouble and experimenting, or following the traditional way.

Two additional ways to achieve the cool factor of the fill up point:

1) Replace the ARF tank with another type of configuration that allows room to run a third line thru the front.

2) Build a custom tank out of metal: http://www.rcuniverse.com/forum/m_98...tm.htm#9818466

huck1199

See my post in this thread
http://www.rcuniverse.com/forum/m_10...m.htm#10112773

AA5BY

Looks like enough room to set the tank back slightly so that the fill line doesn't have to exit the firewall and then come back in.