Great looking fuel tank.
Hopefully this will also simplify the static discharge issue.
On Thu, Mar 20, 2014 at 11:45 PM, bill <bill.sue@orcon.net.nz> wrote:
>
>
> Sue and Bill Sisley
>
>
> -------- Original Message -------- Subject: Re: Europa-List: XS Fuel Tan
k Date:
sue@orcon.net.nz> Reply-To:
> bill.sue@orcon.net.nz To: europa-list@matronics.com
>
> A very happy day as ZK CHV is now back in the air complete with a new
> aluminium fuel tank.
>
> After much deliberation I settled on 2mm aluminium to a design that
> eliminated all the complexity of the plastic tank but increased the volum
e
> to 85Ltrs. The structure was formed by a continuous fold from the rear
> bottom and over the top to front bottom. The sides and bottom are one fo
ld
> each side and one piece tunnel all flange welded for strength with
> cut-outs and inserts to clear controls.
> I made the tank narrower that the previous to allow it to drop straight i
n
> without having to stretch the fuselage and 100mm taller for extra volume.
> No internal baffles were required as the tunnel and cut-outs provided
> sufficient rigidity.
> The outlets and breather are all AN fitings with provision for separate
> water drains and fuel outlets left and right and the fuel return back to
> the inside of the starboard tunnel.
>
> The tank sits free with the bottom rear of the tank sitting on a flange
> off the rear wall of the cockpit module and the front sitting on a full
> width flange off the front wall (seat-back) of the module. A rubber pad i
s
> glued to the tank at all contact points preventing chaffing. The original
> spacers are retained to prevent fore-aft movement.
>
> I raised the sides of the cockpit module to just level of the door sills
> and continued the same angle for the head rests so they are now slightly
> further to the rear.
>
> Fuel is measured with a capacitance probe calibrated in 1 litre increment
s.
> Reserve fuel on the starboard side is 14 litres.
>
> Some pics attached.
>
> Sue and Bill Sisley
> On 12/11/2013 10:38 p.m., nigel_graham@m-tecque.co.uk wrote:
>
> Hi Bill
> If you are serious about constructing your own alloy tank, here are some
> of the issues that I considered carefully before embarking on what turned
> out to be a lengthy project.
>
> Capacity
> If you want to maximise capacity, the tank shape will be complex to take
> advantage of the available space. I went "full span" and put seamless
> tubes through to accommodate pitch control and rudder cables. Since you
> have sawed off the top of your cockpit module, there is now room to exten
d
> the tank vertically up by about 100 mm (to the door sill), this should gi
ve
> you an extra 18 litres. Restore the strength of the CM joint using standa
rd
> "good composite practice".
> This should not compromise the seating or baggage-bay access.
>
> Mounting
> The tank cannot sit on the bottom of the fuselage but should be clear.
> Incorporate supporting brackets to spread the (considerable) load to the
> front and rear of the cockpit module (seat back). Design in some method o
f
> allowing the tank to expand and contract - sitting it on a rubber or cork
> mat for instance.
>
> Breathing
> Use considerably larger breathers than were originally fitted - to preven
t
> pressure build-up and blow-back while filling. If possible use two, one o
n
> each side of the tank. I routed mine up and then down, venting under the
> fuselage, to prevent siphoning or fuel dumping in the event that the
> aircraft ever flipped over.
>
> Fuel Return
> I pondered the ideal configuration for the fuel return line (discussed
> ad-nauseum since!) and opted to return it to the top of the tank. A
> vertical cross-drilled pipe inside the tank allows the fuel to dribble do
wn
> without vapourising or having to contend with the back-pressure of a full
> tank.
>
> Fuel Level Monitoring.
> There are now far more options available to accurately monitor the fuel
> contents. Capacitance level sensors work well but are sensitive to fuel
> type, if you only ever use one type of fuel, this won't be an issue. They
> can be used with a "lookup table" to linearize the readout giving an
> accurate indication of fuel contents. Float switch stacks are the next
> option, (as supplied by Europa) they are reliable and not fuel sensitive
> but give a non-linear indication. I opted for the former but included fou
r
> optical sensors to give an independent indication of fuel contents at
> "Full", 2/3 1/3 and "Reserve" and chose to delete the standard "stand
> pipe", which, without any method of isolating, I considered a safety risk
.
>
> Maintenance
> Now is a good time to include an inspection hatch. Machine a large
> diameter "weld-in" ring with matching cover, tapped for at least six bolt
s.
> Include a groove to accept a Viton "O" ring to seal the joint. This cover
> also makes an ideal mount for the fuel level sender.
>
> Good luck and keep us informed of progress.
>
> Nigel
>
>
> On 11/11/2013 22:43, bill wrote:
>
> Thank you Nigel,
>
> Having got the top off now I can see that the leak is at the shelf on the
> front of the tank where it sits on the mount. It appears that the
> fibreglass had bonded to the tank and with movement caused a fracture due
> to the stress. Having looked at the tank now which is very deformed and
> reducing capacity, I am sure a "metal" one will be much superior.
> Fortunately there are some very good craftsman around here so fabrication
> will not be a problem. Not sure we will get to the same volume as you hav
e
> but will certainly look for more than I have now. Will send some pic,s wh
en
> all done.
>
> Regards
>
> Sue and Bill Sisley
> On 12/11/2013 8:55 a.m., nigel_graham@m-tecque.co.uk wrote:
>
> Hello Bill,
>
> I'm a bit late getting back on this one but as others have said, I built
a
> tank out of 5251 quarter-hard magnesium alloy.
> It weighs 7850 grams and has a capacity of 110 litres.
> I incorporated internal baffles, and breathers with proper AN fittings to
> accommodate alloy pipework. It is also fitted with a full length capaciti
ve
> probe and four solid-state optical fuel level sensors.
>
> http://www.europaowners.org/main.php?g2_itemId=28719
>
> The only advice I would offer is: allow yourself a long time to make and
perfect your cardboard templates - the fuselage is partly conical in sectio
n so the development will be an interesting shape. Choose a welder based on
his ability to weld alloy and don't fall into the trap I did of restrictin
g yourself to a CAA approved welder whose self-belief exceeded his ability!
>
> Nigel
>
>
> On 08/11/2013 21:37, bill wrote:
>
orcon.net.nz>
>
> After 1100hrs I have suffered a failed fuel tank on my XS Mono. Not sure
> exactly where the fault is other than it is high up on the tank. Will kno
w
> more when I get it out.
>
> My question to the forum is, has anyone tried fabricating a metal
> (aluminium) tank rather than using the Polyethylene plastic one as suppli
ed
> with the kit. If so, were you able to obtain the same volume and any othe
r
> advice you may be able to offer.
>
> Many thanks
> XS Mono
> Kit 456
> 914 and Airmaster
> 1100hrs
>
>
> Sue and Bill Sisley
>
>
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