[joedallas]

Can someone Help Please?
I need the
Empty Fuel tank weight with mounting and internal hardware with filler neck
I need this to get the negative moment.

 

[Keith Williams]

Tank Weight

Joe my assembled tank and parts are on the bench but the scale is down the road a bit. Will get it and weigh the parts in a day or so if you do not get a reply by then.

Keith Williams
Milan, IL

 

[Mich48041]

According to my notes from a year ago, the fuel tank weighs about 9 pounds including filler neck and gas cap. Arm is 110.3 inches.

 

[joedallas]

Fuel Tank / Battery ?

Joe is this including site glass inside hardware and the tank modifications by vans
The Fuel has an arm of 110.3. Is the tank and its hardware centered aft of the Fuel?
Also what is the weight of the stock battery and bracket and arm?
I have the arm around 49?. Is this correct?


Thanks

According to my notes from a year ago, the fuel tank weighs about 9 pounds including filler neck and gas cap. Arm is 110.3 inches.

 

[DonFromTX]

I had mine loose and out so just weighed it. With the filler tube and fuel cap attached, sight gauge as well as the Moeller, weighed in at exactly 10 lbs. I was VERY liberal with the pro seal when making it also.

 

[joedallas]

Fine tuning the numbers for wing tank feasibility

Thanks Don
Could also use the weight of the stock Cowl and arm
I have the Arm at 39? is this Close?

I had mine loose and out so just weighed it. With the filler tube and fuel cap attached, sight gauge as well as the Moeller, weighed in at exactly 10 lbs. I was VERY liberal with the pro seal when making it also.

 

[Mich48041]

I weighed Van's tank a year ago with the sight glass but before the frangible bolt attachment mods. There is NO Moeller gauge and almost as much Proseal as Don used.
According to Odyssey's data sheet, the PC680 weighs 15.4 pounds. Looking at Van's RV-12 WEIGHT & BALANCE WORKSHEET, the leading edge of the wing is at 70" aft of datum. By looking at the picture, a rough estimate of the battery arm is 43". For more accuracy, measure from the leading edge of the wing to the center of the battery and subtract that distance from 70". It will help to hold a 4-foot-level vertically against the wing. You probably already thought of doing that.
As for the CG of the empty fuel tank, using the fuel CG of 110.28 is probably pretty close. If you want it more accurate, you could suspend the tank from a wire wrapped around the tank. Move the wire fore and aft until the tank has the same attitude as when installed in the plane.
Joe Gores

 

[DonFromTX]

And, I should have added, the tank has the Vans strength upgrade, weight was without the attaching bolds, frangible and otherwise.

I weighed Van's tank a year ago with the sight glass but before the frangible bolt attachment mods. There is NO Moeller gauge and almost as much Proseal as Don used.
According to Odyssey's data sheet, the PC680 weighs 15.4 pounds. Looking at Van's RV-12 WEIGHT & BALANCE WORKSHEET, the leading edge of the wing is at 70" aft of datum. By looking at the picture, a rough estimate of the battery arm is 43". For more accuracy, measure from the leading edge of the wing to the center of the battery and subtract that distance from 70". It will help to hold a 4-foot-level vertically against the wing. You probably already thought of doing that.
As for the CG of the empty fuel tank, using the fuel CG of 110.28 is probably pretty close. If you want it more accurate, you could suspend the tank from a wire wrapped around the tank. Move the wire fore and aft until the tank has the same attitude as when installed in the plane.
Joe Gores

 

[kmtck]

drawing of the FWF

Thanks Don
Could also use the weight of the stock Cowl and arm
I have the Arm at 39? is this Close?

Joe, look at the image below. i added a 39" and a 49" arm to the drawing to show where they exist based on Van's drawings.

Rahul

 

[joedallas]

Wing Tanks W&B ?

Thanks
It looks like the arm on the battery is about 43” like Joe Gores said.
Is this correct?

Joe, look at the image below. i added a 39" and a 49" arm to the drawing to show where they exist based on Van's drawings.

Rahul

 

[Mich48041]

Thanks
It looks like the arm on the battery is about 43? like Joe Gores said.
Is this correct?

I used that same drawing for my estimate. But I did not print it out, only measured with a ruler held up to the computer screen.
The forward side of the behind-the-seat MID-FUSE BRACE F-1205A is approximately 94" aft of datum. I measured from there to the battery and subtracted from 94" to get 43.5 inches for the battery CG aft of datum. This is not an accurate number but just an eyeball measurement without taking the cowl off. I would wager that 43.5" is within 1/2".
Joe Gores

 

[joedallas]

W&B ?

That?s close enough for now, thanks all.
Now if someone has the total stock cowl weight and the balance point it would help.
And also if it is painted or not?

I used that same drawing for my estimate. But I did not print it out, only measured with a ruler held up to the computer screen.
The forward side of the behind-the-seat MID-FUSE BRACE F-1205A is approximately 94" aft of datum. I measured from there to the battery and subtracted from 94" to get 43.5 inches for the battery CG aft of datum. This is not an accurate number but just an eyeball measurement without taking the cowl off. I would wager that 43.5" is within 1/2".
Joe Gores