SonexBuilders.net

Hi Guys,

Has anyone made up a dip stick to dip the tank with.. assuming its possible to get a straight length of something from neck to bottom!?
I have a FF red cube and Dynon D180 but it would be nice to have a visual method as well.

Cheers
Tony

It seems to me that the shape of the fuel tank, with the filler neck and angled shape, would make this very difficult to achieve accurately. I'm also curious if someone has come up with a solution.

It could be done. Simple wood dowel, with marks calibrated to the gallons.
I think the angle from the neck opening to the bottom of the aft edge of the tank is a straight line. Or would require only a slight bend enroute down.

Something easier than sticking the tank , is I used a red sharpie and a straight edge and placed a mark on the tank every two or three gallons , so all I have to do is peek under dash to confirm my fuel quantity , my gauge has never worked 100% like it should ,
Adam Simmons

Sonex541 wrote:I used a red sharpie and a straight edge and placed a mark on the tank every two or three gallons , so all I have to do is peek under dash to confirm my fuel quantity.

Bingo! The tank is it's own sight gauge. Just graduate the tank as you fill it with marks every so many gallons (your choice - I like 2 gallon increments) and then simply look at the tank during your preflight and you'll know how much fuel you have.

I once had a dip stick for my tank. It was a 1x1 piece of wood marked at every gallon. Because it fits into the tank at an angle the marks are also "angled" on the stick. Don't do like I did and forget it at a fuel stop.

Sonerai13 wrote:Bingo! The tank is it's own sight gauge.

Unless you have one of the old black tanks like mine.

I also marked my fuel tank in two gallon increments and make that part of my prefight, I marked it up to 8 gallons, in mine I can't get any higher to mark it, but still have a good indication on how much fuel is in it.. I am running the MGL Enigma with the Princeton Probe and it is pretty accurate, but when I turn the instrument on to check the fuel level it will read more with the tail down and when the tail comes up in flight the fuel gauge will read less fuel than is really in the tank, so I did all of my calibration with the tail up in fight attitude..

Mike

I use a simple dip stick for the tank made from trim moulding from Home Depot. I use a recangular cross section, about 3/16" x 1", unpainted wood (hemlock or somthing like that because it's already sanded nice and smooth). The angle from the filler neck to the sump area of the tank is a straight line so the stick will go in and the end drops into the sump. This way you know it's all the way in, and I mark a line where the stick rests on the filler neck to make sure it's seated all the way. Add fuel and calibrate with sharpie marks in 1 or 2 gallon increments. The marks will not be evenly spaced due to the shape of the tank, so 1 gal marks work pretty well.

If you laminate the stick it will protect the sharpie marks nicely and seal in any wood fibers, but it makes reading the stick very difficult because the fuel doesn't stick to the varnish and slides down quickly. Leaving it plain will give an easy to see fuel line on the stick where the fuel soaked into the wood slightly.

All this is good to verify the fuel level, but the red cube has proven incredibly accurate and I have really come to enjoy having this information at any given time. It's far better than the old capacitance probe if you run Avgas mixed with car gas! Every fill up I'm within 0.1 gal at the pump, well within my ability to fill to the exact same spot in the fill neck.

Jeff

Sonex 772 wrote: so I did all of my calibration with the tail up in fight attitude..

Okay, I'll ask the dumb question: What is the flight attitude? Obviously it changes with airspeed and a much smaller amount with weight and CG placement, but is there an approximation somewhere that we can use for rough purposes such as marking the tank? I.e. for a taildragger aircraft, on a level surface, the level flight attitude at approx 120 MPH will have the tail XX inches above the ground. For trigear aircraft, the . . . .

I've been tempted to experiment with a plumb bob hanging from the top longeron in flight, marking the location at different airspeeds, but I haven't done that yet. I'm sure there's a better way.