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Lost my measuring stick, retail version only measures to 10 gallons. Does anyone have a stick that would share measurements for 6A? Thanks
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Fuel measuring stick for RV 6A
- Thread starter RV6Seattle
- Start date
Radioflyer
Well Known Member
Isn’t a fuel measuring stick kinda useless in an RV due to the wing dihedral? I mean, most of the fuel in the tank is inboard of the filler port where one would dip the fuel. I just look inside the open filler port and judge fuel by where the fill line is against the closest outboard rib.
planenutz
Well Known Member
I couldn't disagree more.
We have always used a calibrated dipstick and generally speaking its more accurate than anything else you could ever use. The only downside is you can't use it in flight.
Granted, the dipstick is no good to you when there is less than 20 litres (5 gal) in the tank as all you can see is the bottom of the tank and your awesome prosealing ability, however from 25 litres (6.6 gal) my dipstick is calibrated at 5 litre (1.099864 gal) increments. Prior to flight I dip the tanks and correlate the data with the GRT 4000. The amount of dihedral is irrelevant in that the dipstick still works very well - and why would you not want to know your exact fuel level before going flying??
Hi, Please post your measurements. I never thought about it, but a dip stick would be good to have. Steve
I bought one of these years ago and dip the tanks before every flight. Every 1” on the stick is 1.5 gallons in the tank. To get quantity in tank just multiply the inches the stick reads by 1.5 and add 4. Like others have already mentioned, it is pretty accurate down to 5 gallons.
www.aircraftspruce.com
Calibration curve for a 6A.
Fuelhawk Universal 11 Inch Fuel Gauge | Aircraft Spruce
Fuelhawk Universal 11 Inch Fuel Gauge The Fuelhawk is clear lightweight and unbreakable. It's easy to use and gives an instant readout in gallons usable. No more guessing.
Calibration curve for a 6A.
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BillL
Well Known Member
OP - you have the information now. I used 1/16" holes drilled in my .025" aluminum stick. Otherwise the meniscus or soaking if a wood stick won't allow reading to the 1/2 gal accuracy of the marks. Also, to get 1-2 qt accuracy with fill, dip readings, and fuel totalizer, add the left and right together to eliminate inaccuracy of non-level airplane. For a single tank it can be off 1/2 gallon just due "leaning" with more fuel in one than the other.
MacCool
Well Known Member
Sticking the tanks is the first thing I do with every preflight. I calibrated it myself at the same time I calibrated the fuel level component of my EFIS. I started with empty tanks and added 2 gallons at a time for the EFIS and then, at various other increments for each tank, calibrated the homemade dipstick. I find it very accurate and I can't envision not doing such a simple evaluation of such a critical flight component (fuel level).
I've seen others post their own dipsticks for the RV – 9A and thought that would be great to make my own so that I wouldn't have to calibrate one myself starting with empty tanks. However, I found that numbers and devices posted by others for the same airplane didn't correlate with mine. I don't know why my 18 gallon tanks should be any different than any other -9A, but I've not found other dipsticks to accurate for my airplane. .
I've seen others post their own dipsticks for the RV – 9A and thought that would be great to make my own so that I wouldn't have to calibrate one myself starting with empty tanks. However, I found that numbers and devices posted by others for the same airplane didn't correlate with mine. I don't know why my 18 gallon tanks should be any different than any other -9A, but I've not found other dipsticks to accurate for my airplane. .
I went the spendy route after the one my builder supplied broke in half. Ir was a yellow ruler wiith the gallons marked with a sharpie. It worked well. I could have "built" a replacement but I didn't have any extra wooden dowels laying about.
This is the one I purchased
This is the one I purchased
I would think you'd need to make one taylored to your aircraft? I made mine with a paint stick, marked with a sharpie. One side is Left tank, other side is Right tank.
Drain the tanks (takes 15 min), then add in gas 5 gal at a time, dipping the stick and marking for every 5 gal. My right and left side are slightly different, by about 2 gal difference.
Drain the tanks (takes 15 min), then add in gas 5 gal at a time, dipping the stick and marking for every 5 gal. My right and left side are slightly different, by about 2 gal difference.
Roadjunkie1
Well Known Member
Agreed! Dipping my tanks is such a part of my preflight I can't imagine NOT doing it! It would be like walking out of the house and not tying my shoes! Or something like that!
I don't remember where I got my hollow plastic tubing; probably the Aviation Section of Home Depot but would probably be easy to find online. I started with empty tanks and filled them with ONE-gallon increments (I'm OCD, remember!
) and that way I knew exactly how many gallons were beyond my measuring tool and how much I could measure. I marked the stick by gently using my little tubing cutter (one turn) and then 'branding' that with my small metal number stamps. I have one for the hangar and a not so detailed one in my tool bag. I like knowing how much go juice I have to go......and kind of like the smell of 100LL. Not as much as the smell of 80/87, but I digress......
I would suggest making your own and not relying on the measurements others have for their airplanes. 1) every airplane is different. 2) the method they use when sticking the stick in the tank might be different than you. Is it done straight up and down or is it at an angle.....?
YMMV.............
MacCool
Well Known Member
Yes, it doesn't take long to empty fuel tanks, but naturally an adventure such as draining the fuel tanks comes with many warnings about the hazards associated with that much open fuel in the hangar.
When I drained mine, I flew one tank empty then the other down to as low a level as I was comfortable with within gliding distance of the airport, then removed all the drains and emptied what remained into some grounded 5-gallon cans. I took the opportunity to kill multiple birds with that stone. The fuel drains were dripping so I wanted to replace them (yes, I knew I could have just replaced the O-rings). I also had a new upgraded EFIS so I needed to recalibrate fuel senders, I wanted a new empty weight, and I wanted to make sure the pre-flight measuring tube was accurate.
Ralph Inkster
Well Known Member
Should be noted that some guys dip their tanks differently. Dip stick held in the center of the filler hole will get a different reading compared to same stick supported to the front or rear edge of the filler hole.
Also stick being held vertical to the ground compared to one 90 degrees to the cord line.
Verify the dipping technique before accepting someone else’s stick dimensions.
Also, a A model stick will likely have different dimensions than a tail dragger.
Also stick being held vertical to the ground compared to one 90 degrees to the cord line.
Verify the dipping technique before accepting someone else’s stick dimensions.
Also, a A model stick will likely have different dimensions than a tail dragger.
I have used this universal stick since day one on my 7a. I use it at the start of the day. You can create a calibration chart from 6 gallons all the way to full. I use it to set my fuel computer on my Advance Flight System 2500.I bought one of these years ago and dip the tanks before every flight. Every 1” on the stick is 1.5 gallons in the tank. To get quantity in tank just multiply the inches the stick reads by 1.5 and add 4. Like others have already mentioned, it is pretty accurate down to 5 gallons.
Fuelhawk Universal 11 Inch Fuel Gauge | Aircraft Spruce
Fuelhawk Universal 11 Inch Fuel Gauge The Fuelhawk is clear lightweight and unbreakable. It's easy to use and gives an instant readout in gallons usable. No more guessing.
Calibration curve for a 6A.
planenutz
Well Known Member
RV6 Seattle - I made the dipstick for my "6" from a sacrificial broom handle. The first photo below provides dimensions. l then epoxied in a nylon hook to easily flip open the fuel caps. You'll notice that at the lower end there is a notch in the side... the oil hatch on the top cowl is not spring loaded open and the dipstick serves as a prop to keep the hatch up when topping up the oil - the notch in the dipstick keeps it in place on the lip of the cowl. The measurements are correct when the dipstick is placed at the rear of the tank opening, although they're very close even if you're in the middle.
My caps have a built in dipstick made from 0.063" aluminium and are calibrated in 5 litre increments. On the subject of the left cap shown in the photo, this was from my father's RV-12 and I had it inscribed in rememberence. Some people might think its bad ju-ju but the heck with that - I'm proud to have a piece of his plane flying with me all the time as a tribute.
My caps have a built in dipstick made from 0.063" aluminium and are calibrated in 5 litre increments. On the subject of the left cap shown in the photo, this was from my father's RV-12 and I had it inscribed in rememberence. Some people might think its bad ju-ju but the heck with that - I'm proud to have a piece of his plane flying with me all the time as a tribute.
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Same here. Use a paint stirrer with marker lines at 5 gallon increments. I can't imagine needing to know the fuel level to 1/2 gallon increments before take off.
MacCool
Well Known Member
Agreed. The fuel computer in my EFIS is accurate to about 1/10th gallon and my tank gauges are similarly accurate, although don't begin registering until down about 1/3rd. I stick my tanks mainly to confirm that they roughly agree with the gauges at the beginning of a flight.
Hangar 1271
Well Known Member
I also took an old piece of wood to make my fuel stick but I seem to be the only one who calibrated it at an angle to reach the back of the tank on my -8. That way I can measure the fuel to almost empty. I also put a screw in the end and bent it to use as pry for the cap.
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PilotjohnS
Well Known Member
I really, really like this idea. I am going to copy you. I like this better than the stick, because it will always read the same since it is not subject to be tilted,
thank you for posting
Hangar 1271
Well Known Member
I forgot to ask about the cap dipstick. How did you attach it to the bottom of your caps. I would appreciate a picture of the bottom of the cap. Thanks.
[email protected]
Well Known Member
Now this I would like to see.
I fly an RV-6A there is virtually no way to measure the last few gallons as they are over there in the bottom of the wing.
I do have a stick but haven't used it in years.
My luck varies FIXIT
I take a different approach on my RV-4.
My stiffener rib under the inlet aligns with half full when the fuel is at the top of the stiffener. I maintain 1 hour fuel reserves. both tanks are half full or better, I am good for an hour. If one side is below half full, I fill it up. With one full and the other over half full, I am good for two hours. If it is a long flight, I top off both tanks. I have also gotten pretty good at estimating fuel pretty accurately visually.
I do have a fuel stick. For a long time I measured the fuel height, marked it on the stick, and then filled up. It is spot on after several fill ups.
My stiffener rib under the inlet aligns with half full when the fuel is at the top of the stiffener. I maintain 1 hour fuel reserves. both tanks are half full or better, I am good for an hour. If one side is below half full, I fill it up. With one full and the other over half full, I am good for two hours. If it is a long flight, I top off both tanks. I have also gotten pretty good at estimating fuel pretty accurately visually.
I do have a fuel stick. For a long time I measured the fuel height, marked it on the stick, and then filled up. It is spot on after several fill ups.
planenutz
Well Known Member
planenutz
Well Known Member
That part is proprietary information and the reason for the patent.
Funny enough I used the nut that holds the cap together. Simple as that.
Two things to keep in mind - first is the radius of the bend needs to be significant to avoid cracking and you need to make sure you make that bend across the grain and not with it, otherwise you might one day lift the cap to find the dipstick is on its own journey. Second thing is you'll notice I placed a very slight kink in the vertical face of the dipstick to reduce the possibility of vibration that might induce a stress fracture at the bend. Vibration is dampened when the fuel is in contact with the dipstick obviously, but I didn't want it buzzing around in free air when the tank was near empty. As previously mentioned these are made from 0.063" alclad... oh, and the holes are 3/32" but I'm not sure that matters so much as I took to the surface with a light touch of scotchbrite and the fuel seems to "stick" to the dipstick quite nicely for long enough to read it.
Fill yer boots.
