Minimalistic gas tanks

[cluttonfred]

I like the suggestion of a generator tank because of the flat shape, some are available in plastic which would be lighter than the steel ones.

Another is a cylindrical spun aluminum fuel tank as uses in dune buggies. This one is 8” diameter and 24” long for 5 U.S. gallons.

 

[challenger_II]

I have used these with very satisfactory results:

2-1/2 Gallon Natural Multi Purpose Tank - 12.75" L x 7.86 W x 7.75" Hgt. (2.25" Neck) | U.S. Plastic Corp. (usplastic.com)

One may tap the tank on top, or bottom.

 

[WonderousMountain]

Installed to original location,
this 10by20 holds one gallon
more while leaving sideroom.

Minimalistic, not fool proof.

 

[rtfm]

Sigh... Nothing is simple, is it?
It looks like a single tank mounted inside the airframe behind the firewall with a fuel pump. All this talk about fuel starvation with wing tanks is giving me pause for thought. I might just settle for a 25 litre tank directly on the CG inside the airframe, with an external (transparent) pipe to visually display fuel level. Fuel filler cap pokes out the side of the airframe. I can make the tank quite easily, and all I have to do is to buy the hardware, and a fuel pump.

 

[rotax618]

Fuel in the fuselage is the best option for a Flea, a large sloshing mass in the wing will have some effect on the pitch control.

 

[nestofdragons]

If ever Hans Engels was planning to place his fueltank in the rotating wing of his redesign of the HM16, it cannot be a bad idea.
Front wing tanks are really not that uncommon in Flying Fleas. Several have the fuel tank there.


Sadly Hand never finished his project after he lost his balance sensitivity and never would have been able to fly again.

 

[Bill-Higdon]

I like the suggestion of a generator tank because of the flat shape, some are available in plastic which would be lighter than the steel ones.

Another is a cylindrical spun aluminum fuel tank as uses in dune buggies. This one is 8” diameter and 24” long for 5 U.S. gallons.

View attachment 125314

It's rumored that Barnaby W. likes them.

 

[Bigshu]

View attachment 124074
"20,000 rivets flying in close formation."

What is this aircraft?

 

[Bigshu]

There's no way I'd build an airplane with a common sump and an on/off fuel selector. Both Long EZ's I built had a gravity a fed sump under the passenger thigh rest with a partition in the center for L/R tanks and a flop tube in one side for inverted flight. With a common sump if you lose a fuel cap all the fuel gets sucked out of that side..... and then the other side. It's happened with EZ's.

Can you install ball checks to keep fuel from flowing from full to empty? Fuel can flow downhill to the selector valve, but can't flow back uphill from higher head pressure to lower. Lose a cap and only one tank empties.

Amazon.com: Amrxuts 10mm 3/8" Fuel Non Return One Way Check Valve Petrol Diesel Fuel Oil Water Aluminium Alloy : Automotive

This one might not be a ball check, maybe wafer, and can't use with gasohol, but there are lots of choices.

 

[pylon500]

If ever Hans Engels was planning to place his fueltank in the rotating wing of his redesign of the HM16, it cannot be a bad idea.
Front wing tanks are really not that uncommon in Flying Fleas. Several have the fuel tank there.
View attachment 125770
Sadly Hand never finished his project after he lost his balance sensitivity and never would have been able to fly again.

Yeah, REALLY don't like the idea of fuel at that location!
One might say it can double up as a mass balance for the wing, but do you really want a wing that becomes progressively unstable as the fuel burns off?
Keeping the tank (somehow) centred around the wing pivot point might work, but awkward to do.

 

[nestofdragons]

Yeah, REALLY don't like the idea of fuel at that location!
One might say it can double up as a mass balance for the wing, but do you really want a wing that becomes progressively unstable as the fuel burns off?
Keeping the tank (somehow) centred around the wing pivot point might work, but awkward to do.

I understand fear. But ... i am pretty sure that it is not needed to fear this placement of fuel tank. It has been done too many times and in Flying Flea world there is no warning of "don't place the tanks in the front wing". I guess i would have heard it if it was. Remember ... the rotating wing always pulls a bit on the stick. If the fuel tank is in the front of the front wing it takes a bit of the pull force away. And ... force needed to move the front wing is not that high with or without fuel tank in front wing.

 

[rotax618]

Locating the tank in the LE of the Flea’s wing probably works, structurally it is a good idea, it negates some of the flying loads taken by the struts - unfortunately struts are weakest in compression so landing loads are more concerning. The Flea has a thin wing with the spar relatively far forward, so the tank in the LE won’t have a very large capacity. Most of the aircraft I have built and designed have the fuel in the wings, immediately behind the spar - more or less at the CG - the Boorabees carried 50litres/side for 100litres and the ICP Savannah has 4 tanks, two/side for 140litres.