Author Topic: LE and XL Fuel System (Read 15433 times)

PropMan · « **Reply #15 on:** October 09, 2017, 10:12:09 AM »

Thanks fellas.

Poormam- I used 2024T3 cuz I had some, would probably be better to use 0 instead of 3 for forming.
Bottom skin is .032
Ribs are .025
Top will be .040

Bob- I hope to come in under 3lbs. Once my ACS order comes in I will dril and fit the top skin, then rivet together. Then it can be weighed

Bob Wood · « **Reply #16 on:** October 10, 2017, 08:06:47 AM »

Frank,
Sounds great. did you consider baffles to reduce sloshing as well as for bottom support? I was thinking of going the baffle route. More holes to seal maybe but not too bad.

Keep the info coming, great project. Seems like a 5 lb savings over the Team Mini max plastic tank.

I went to solid struts, and no paint to make my weight. Thinking of redoing my tank so I can paint!! The struts are not a big deal I flew with them both and without, and seemed to me if I came in hard I would bend metal either way!! The solids are just fine. Keep the speed up[!!

Bob

scottiniowa · « **Reply #17 on:** October 10, 2017, 10:38:06 AM »

Quote from: PropMan on October 09, 2017, 10:12:09 AM

Thanks fellas.

Poormam- I used 2024T3 cuz I had some, would probably be better to use 0 instead of 3 for forming.
Bottom skin is .032
Ribs are .025
Top will be .040

Bob- I hope to come in under 3lbs. Once my ACS order comes in I will dril and fit the top skin, then rivet together. Then it can be weighed

A FEW words on tank building..for those that have never built with Alum.

you have to be a good metal worker like Frank, to make 2024-T3 work in this situation. The reason is simple- if you don’t pay attention to bend radius, the alum can and will crack in the bends. By doing it right- you have a mighty tuff tank, but doing it wrong, you could have cracks that haunt you. There are bending rules for each thickness (same rule, just different radius mins. - for each thickness)

And most know- there is zero welding on 2024-T3, so that is not a fix option or add a tab option before filling the tank.

Lots of ways to skin the cat, these "outside flange- wing profile tanks"- have a lot going for them.

cheers
scott

PropMan · « **Reply #18 on:** October 11, 2017, 06:39:30 AM »

A few more details done while waiting on my ACS order.
Fittings made and drilled for the fuel line, vent and sump.

The fuel line/finger strainer attach is 1/4 plate tapped for 3/8" pipe thread drilled for rivets, then drilled to the tank in two locations (i tried to determine the lowest for and aft position for fuel pickup that would allow the most usable fuel from the tank). The finger strainer is from Wicks pt#FS375-125. These are also on the outside of the tank skin to allow more usable fuel(see pic).

The Fuel sight gauge and header tank vent are on the inboard rib. The attach plate is made of a piece .20 material i cut from some angle, could have used the .25 but saving as much weight as possible and the 1/8" fittings have plenty of thread contact on the .20. These are drilled for 1/8 pipe thread, tapped, drilled for rivets and drilled to the inside of the tank. Installing them inside allows for the fittings to fit close to the rib and makes tank install to the wing easier.

To assure the header tank is vented properly back to the fuel tank an AN fitting was installed in the upper front rib wall(next to upper sight gauge fitting), then the fitting is drilled out to accommodate a 1/4" tube which is secured and routed to a high point near where the fuel fill will be.

PropMan · « **Reply #19 on:** October 11, 2017, 06:48:18 AM »

Quote from: Bob Wood on October 10, 2017, 08:06:47 AM

Frank,
Sounds great. did you consider baffles to reduce sloshing as well as for bottom support?

Bob- Yes, i decided against baffles, hope its a good decision. Trying to save weight. the bottom of the tank has two .020 strips of angle for stiffeners. My thought process on both of these decisions were: 1) 5 gallons Usable will only be in the tank for a short while and shouldn't slosh around enough to be a problem. 2) the thin bottom skin .032, definitely needed support. plus i referenced my old RV6 fuel tank drawings and it had stiffeners between ribs on the tank bottom.

These stiffeners will be trimmed to save weight where possible also.

leshoman · « **Reply #20 on:** October 11, 2017, 01:03:11 PM »

Regards baffles on a Legal Eagle XL 5 gallon fuel tank, the only sloshing around that will take place is when taxiing. My tank is made of .032 and it has never been a problem.

PropMan · « **Reply #21 on:** October 15, 2017, 05:52:19 PM »

Finished drilling the top skin. And test fit to the wing.

s johnson · « **Reply #22 on:** October 15, 2017, 09:13:15 PM »

Frank,

Looks absolutely Fantastic.. Wonderful fab work.

Scott J.

Tom H · « **Reply #23 on:** October 16, 2017, 05:16:35 AM »

Ditto on what Scott J said!!!!

Leonard · « **Reply #24 on:** October 19, 2017, 09:40:17 AM »

Hi Guys,
If you fly a carburetor that has no bowl be sure to turn off the fuel in a engine failure as the fuel will keep flowing and a fire can be the results. I have seen this. Leonard

PropMan · « **Reply #25 on:** October 19, 2017, 06:57:57 PM »

Thanks for the complements everyone!

Started proseal and riveting the tank together. I have broken this task up in a few nights, don't think i could handle this in one session. wayyyyy to much mess!!!