Fuel tanks

Model Specific Discussions about the Sling TSi.
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scout
Posts: 25
Joined: Mon Nov 22, 2021 5:31 am
Location: US

Fuel tanks

Post by scout »

Why don't the fuel tanks in the TSI go all the way to the front of the wing ? There is an empty space in the leading edge front of the wing. Could fuel occupy this space. Seems like filling this space with fuel with, obviously would allow for more fuel,, but also move the cg forward. ?? What are the cons of this ? Why is this not already done ? Fear of bird strike ? It is an option that some do on various rv's. The TSI long range fuel tanks go all the way to the leading edge,,, so why not the main tanks ?
Cluemeister
Posts: 87
Joined: Mon Nov 25, 2019 4:15 am
Location: Tennessee

Re: Fuel tanks

Post by Cluemeister »

The huge main tanks are a big plus on the Tsi. With its miserly gas usage, the range on standard tanks is over 6 hours at 8gph. I have complaints on the Tsi, but fuel tank range is definitely not one of them.
scout
Posts: 25
Joined: Mon Nov 22, 2021 5:31 am
Location: US

Re: Fuel tanks

Post by scout »

Agreed. Putting fuel in the leading edge would be more of a CG helper, than a range extender.
Cluemeister
Posts: 87
Joined: Mon Nov 25, 2019 4:15 am
Location: Tennessee

Re: Fuel tanks

Post by Cluemeister »

I agree the aft CG is the worst aspect of the Tsi. If you don't have the chute, not so big a deal. But with the chute, it's frustrating for sure.

I'm still waiting for another Tsi owner to come up with a definitive aftermarket solution for this issue, i.e nose wheel weight, steel plate in floor, etc.

I'd do it, but I'm too lazy to do the research!
scout
Posts: 25
Joined: Mon Nov 22, 2021 5:31 am
Location: US

Re: Fuel tanks

Post by scout »

I am also curious,,,, if there was fuel contacting the leading edge,, would it take longer for ice to form on the wing ? Seems like if there was more thermal mass, it would take longer to change that mass. Especially on take off. If the ground level was warmer and you are flying up through a layer.
Obviously, the hor stab and prop's would be the same, so that would be a problem.
AaronG
Posts: 20
Joined: Tue Nov 26, 2019 10:58 am
Location: Dallas-Fort Worth Area

Re: Fuel tanks

Post by AaronG »

Does anyone have pictures of both the left AND right stock fuel level senders orientation when installed they can share? Specifically the float arm view.

#slingsupport
Building Sling TSi since Jan 2020
AaronG
Posts: 20
Joined: Tue Nov 26, 2019 10:58 am
Location: Dallas-Fort Worth Area

Re: Fuel tanks

Post by AaronG »

Checking here one more time before moving on with build. Have not been able to obtain comparable pictures of both left and right fuel senders installed anywhere, so posting my tank pictures below for comments. Flipping the left fuel sender over does get the 180 ohms reading when tank is full so assuming this is the correct orientation.

The last open issue is instruction on sheet 36 of the wing manual - "It should leave a space of approximately 2mm between the skin (top & bottom) and the floater ball". On both tanks the float ball hits the tank skin before the float arm contacts the stops built into the fuel sender. I have tried slightly different arm bends, changes in distance from arm bend to screw, etc but haven't found any combination that allows arm to hit stops at both limits and still stay in the 180-3 ohm range on both ends of spectrum. I did triple check that arm bend is 67 degrees, and its 45mm from arm bend to screw on sender and its 123mm from bend to float. I am hoping am missing something simple here, but keeping the correct ohm range and the 2mm gap to skin is not clear. Any thoughts from those that have completed? The only other idea is to slightly bend the sender stops so the arm engages before float hits the skin but damage potential for that approach is unknown.

Update 3/11 - I got a clarified response from tech support in SA. They discussed with their factory builders and commented "stopper arms may be bent by the installer to the correct position". So used a hand seamer to gently bend both stop arms until there was a 2mm gap between float and skin on both ends of the arm range. It was something simple, back to building.

Google Photos
https://photos.app.goo.gl/iBGv6HBeyEsn7wf69
Building Sling TSi since Jan 2020
AaronG
Posts: 20
Joined: Tue Nov 26, 2019 10:58 am
Location: Dallas-Fort Worth Area

Re: Fuel tanks

Post by AaronG »

Not sure if others have this same variance...on my kit for both the left and right fuel tanks, the end rib (WG-RIB-202-R-F-3 Fuel Tank Rib 202), came with the tooling hole punched to 6mm not the 4.8mm the plans call for. Therefore, the 1x 983 sealed rivet called for on sheet 28 would not work. This is the same tooling hole size that all the other tank ribs have except the last rib, WG-RIB-216-R-F-1 Fuel Tank Rib 216 which does have the correct 4.8mm hole size.

Discussed options with factory - options reviewed were installing a doubler plate with a drilled 4.8mm hole so 983 rivet works or 6mm sealed rivet. I went with the single 6mm rivet option since it was relatively easy to source in the US. Factory emphasized with either option to apply "sufficient" amount of sealant to seal the tank in this area.

Sourced from McMaster-Carr part # 97524A109 if interested in researching for your project.

This is a large rivet to pull and I had to get another hand rivet tool that had large enough nosepiece to handle - this one was used
Building Sling TSi since Jan 2020
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