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  #11  
Old 10-05-2011, 09:10 AM
prkaye prkaye is offline
 
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Location: Ottawa, Ontario, Canada
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Quote:
Page 6-14 in the install manual...
Is this what you're looking for?
No. That doesn't answer my question about whether the Dynon will allow you to do the totalizer thing independently for each tank. However, Brian and Stephen have confirmed my understandign that the answer is NO. A real shame, because this functionality would only require a software update, and the extra code would be pretty simple (essentially duplicating the code they already have for the totalizer and modifying the interface).
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  #12  
Old 10-05-2011, 09:22 AM
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schristo@mac.com schristo@mac.com is offline
 
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Location: WA
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Default ???

If you use the totalizer to display tank level you would end up ignoring the only mechanical measure of actual fuel and would not account for undocumented changes in level... from a leak, draining sumps, syphoned away, or more typically from adding fuel and forgetting to hit the reset. Even though the tank levels might not be as accurate as they could be they are from a real mechanical reading rather than a derived virtual value; that's a good thing for redundancy in a critical system.

For anyone; if your level sensors are significantly in error, check the calibration data.
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  #13  
Old 10-05-2011, 09:38 AM
prkaye prkaye is offline
 
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Quote:
and would not account for undocumented changes in level... from a leak, draining sumps, syphoned away
Good point there. But you're not objecting to the capability, really - just to its potential for misuse. By your observations, obviously one would want to only use this capability supplement visual checks and the fuel gauges.

I generally think more information is better, but as with anything, if the information isn't properly managed and combined with other sources, it can certainly be mis-used. I certainly wasn't advocating using fuel totalizers as the *sole* mechanism for fuel management.

Quote:
For anyone; if your level sensors are significantly in error, check the calibration data.
Yeah, I should probably drain the tanks one of these days and re-do my calibration procedure. I just need to find a time when nobody will mind me hogging the fuel pumps for the time required to do this.
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  #14  
Old 10-07-2011, 08:09 AM
yakdriver yakdriver is offline
 
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Location: Twin Falls, ID
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When you calibrated your tanks was the airplane in flying attitude? My Dynon is right on the money on fuel level and fuel flow. When I fill up I can tell you within 1/10gal how much it will take. How do you expect the Dynon to tell you fuel flow and total from each tank when the transducer is between the engine and fuel selector. You would have to have two transducers one one each side before the fuel selector to do that.
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  #15  
Old 10-07-2011, 09:59 AM
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dlloyd3 dlloyd3 is offline
 
Join Date: Jun 2005
Location: Locust, NC
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Default fuel level

I agree with Yakdriver, my float senders and Dynon are very accurate in staight and level flight, the best of any airplane I have owned. They are totally inaccurate on the ground because of the tailwheel attitude. They are totally inaccurate in flight if not in co-ordinated flight, the ball off center will also show how the fuel sloshes over to one side of the tank affecting what the fuel float sees. Does your airplane fly ball-in-center? If not, correct that first. If I run a tank in flight until it shows four gallons, it will take 16+ gallons to fill. Drain your tanks, level your airplane and recalibrate. Your setup should really work great. Unless you had a faulty sensor connection on one tank, I doubt you would have that problem with both tanks.
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  #16  
Old 10-07-2011, 01:52 PM
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Flybuddy2 Flybuddy2 is offline
 
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The fuel flow, with the proper K factor, is VERY accurate. After you've filled tanks a few times and feel comfortable that it IS accurate, you can use it to help adjust your fuel gauges. Simply run on one tank only, burn X amount of fuel and then adjust the sender value till you match what you know is in there. Say you use 9 gallons in one tank, adjust the gauge till it reads half. Look at other values and if they are not fairly linear adjust those also.
Right down the current values before you start. If they are not accurate now, you've got nothing to lose and it's easier than a full re-calibrate.
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  #17  
Old 10-07-2011, 04:34 PM
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Ron Lee Ron Lee is offline
 
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It might be simple to press a button for left tank or right tank. But what if you forget...and people will. The TOTAL fuel as based up the fuel flow hardware/software is very accurate once the K-factor is calibrated.

Then you can use ops procedures to ensure that you know how much is in a tank.

Example: Run ten gallons (use fuel remaining from the fuel totalizer) then switch tanks. Once you have run ten gallons from each tank you have about one hour duration in each tank and can select how low you will go on the remaining fuel before you switch tanks.

My guess is that this is a far better solution that what you wish to do.
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  #18  
Old 10-30-2012, 10:36 AM
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RVG8tor RVG8tor is offline
 
Join Date: Mar 2007
Location: McKinney, TX
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Default Step to calibrate

For those that have done the Dynon fuel gage calibration can you tell me the steps. I need to do this soon. Instruction book says follow on screen directions. I want to make a checklist for this so I don't tie up the pump longer than I have to. I know level the plane first then what, two gal at a time, is a helper to man the fuel nozzle a good idea? Can I record this stuff inside the Dynon and get it later? If you can give me a summary of the steps it would be greatly appreciated. Thanks for the help.

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  #19  
Old 10-30-2012, 11:06 AM
RV8R999 RV8R999 is offline
 
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The physical location of the float sensors and dihedral of the wing will prevent accurate fuel level readings above about 16gals per tank as the floats will be at their highest point at 16gals (RV8 tanks).

I had a helper push the buttons on the screen as I added the fuel. If your calibration is the first time the tanks have been full since construction I recommend you give the wing a good rap with the palm of your hand just above the float location. Do this after each 2 gal addition prior to pushing any buttons. This helps ensure the senders break free of any residual friction present after sitting in a fixed position for several years. If you don't do this you'll likely get a very flat calibration curve which will be totally inaccurate.
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  #20  
Old 10-30-2012, 11:11 AM
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pierre smith pierre smith is offline
 
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Location: Louisville, Ga
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I have the D-120 engine monitor in the -10, probably all the same circuitry as your 180 and is super accurate, regarding remaining fuel and fuel at the arrival waypoint. The tank gauges are also very accurate and I check the fuel added every time I gas up and it's within tenths of what it said remained.

All that's important is fuel remaining to me, not which tank it's in...that's my job.

Best,
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