What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

fuel stick

seagull

Well Known Member
This is specific to the original RV-12 with the tank behind the co-pilot seat. I use this on every flight. My original fuel measuring stick was a 5/16 wooden dowel extremely warped, (Home Depot stocks lots of the warped ones). The curve is necessary to fit down the filler neck. I drained the tank and filled it 1 gallon at a time and calibrated the dowel. These marks were also transferred onto the computer to create a full size drawing so I could reproduce the fuel stick.
The wood dowel worked fine but it eventually broke almost dropping the broken end into the fuel tank.
Bored I decided to make the ultimate fuel stick with the exact curve to navigate the filler neck of the -12.
Making a curved composite rod was harder than I thought. I made it using carbon fiber tow and epoxy, then grooved the gallon marks and painted them in with white paint. The stick is sanded with 220 grit for a matt finish to contrast with the wet fuel.

I made 2 sticks with different curves that are required for the different gas caps, standard and locking, the pictures are labeled. The difference is the curve that makes it drop through the neck easy.

Download and print the picture on 3 pages, use landscape mode, and print in default image size. Tape the 3 pages together at the arrow marks and confirm it is the correct size with the 24” scale line.

IMG_6103.jpg

IMG_6104.jpg

IMG_6110.jpg
wetted with fuel

RV-12 fuel stick_s.jpg
standard gas cap

RV-12 fuel stick locking cap_s.jpg
locking gas cap
 
Last edited:
I can help with the website if you want to take orders and when you make one for the 12iS new tank design, I’m a customer.
 
Fuel sticks

I have made 2 of these, one with round dowel, one with 1/4 square dowel. Quite a bit easier to see the fuel on the face of the square one. The bend is easy to achieve by steaming over a pan of boiling water. Sand the end nearly to a point to navigate down the fuel neck. From one who knows: do not leave stick on wing when taxiing back to hangar, you won’t see it again & will have to make another…
Cheers, Dean
 
I use a piece of translucent brake line and use it as a dip tube. It easily goes around the bend in the filler neck and I don’t have to worry about breaking it.
 
Fuel dip stick

Rich,

I like the simple translucent brake line idea, how do you mark the lines for the fuel quantity? I made some wooden dowels for my -8 and stained them, painted the fuel marks and sealed them. They look nice but still a bit hard to read the fuel on the stick.

I also like the carbon fiber idea. Any place to just buy some small CF rods and mark them myself?
 
maybe a little pricy but over and done......arrows are made of carbon fiber these days.i've had one in my hangar 10 yrs marked for the last plane i built.
 
maybe a little pricy but over and done......arrows are made of carbon fiber these days.i've had one in my hangar 10 yrs marked for the last plane i built.

Carbon Fiber Rod is pretty stiff and won't negotiate the bend in the filler neck very easily. I made a measuring stick from 3/16” wooden dowel and filed small notches at the gallon marks. Tip of rod should be rounded to skip past tank flange. I think I used a lead pencil (graphite) to highlight the marks. Leave dowel un-treated so fuel absorbs and is easily seen against the dry wood.

In any event… I stopped using the stick when I added the Moeller float gage on the top of the tank. Dead accurate and very repeatable. Excellent for monitoring fill level when adding fuel to prevent overflow.

I bought a placard from Aircraft Engravers to quantify the Moeller gage. Cost was $28.
-
 

Attachments

  • AF5DDFAD-6ADC-4C26-A6A1-0571D0D217C6_1_105_c.jpeg
    AF5DDFAD-6ADC-4C26-A6A1-0571D0D217C6_1_105_c.jpeg
    125.6 KB · Views: 57
  • 728B5E29-1E5E-4485-B08F-DD235162C7EB_1_105_c.jpeg
    728B5E29-1E5E-4485-B08F-DD235162C7EB_1_105_c.jpeg
    411.8 KB · Views: 110
  • 0AD2DD75-F42F-45C6-9DAD-C4DEF1BC2BF2_1_105_c.jpeg
    0AD2DD75-F42F-45C6-9DAD-C4DEF1BC2BF2_1_105_c.jpeg
    355.7 KB · Views: 90
  • 18BFEFF0-7713-433D-B13F-94A53C30A0DD_1_105_c.jpeg
    18BFEFF0-7713-433D-B13F-94A53C30A0DD_1_105_c.jpeg
    184.5 KB · Views: 110
You are all right, carbon is way over the top for a fuel stick. As I said in the beginning i had some time to burn so it wasn't an issue. I spent many years in the aerospace industry working with composites so this was right in my wheelhouse. I don't know of a way to produce these for a reasonable price considering the time involved.

My stick is laid up carbon fiber filament infused with epoxy. The process requires a mold that is in the final shape (curve). The stick, once cured has very little flex. After curing the lines were cut deep enough to hold white paint, paint that isn't affected by the gasoline. After the paint is dry the stick is surface sanded so the paint is flush with the carbon. One secret to making it readable is the sanding vs leaving it gloss.

When I made a stick using a wood dowel, (obviously you have to start with a dowel with the correct curve to navigate the filler neck). I coated the stick with slow set JB Weld, warmed it with a heat gun to make it flow like paint and brushed it on. Then sanded it with 220 wet / dry. I then added the marks with the corner of a triangle file around the dowel, no paint on this one. The sanded JB Weld is light grey but darkens when wet it very readable and the JB seals the surface so repeat readings are possible.
 
Last edited:
Oly,

I calibrated the translucent dip tube in 5 gallon increments when I did the initial tank level calibration. Note that it’s pretty much linear until you get to the last 5 gallons when the filler neck begins to fill up.

I put notches on the tube to mark the 5 gallon increments. Be careful to not go through wall on the notches.

Rich
 
Back
Top