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  #11  
Old 06-14-2017, 09:50 AM
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Mel Mel is offline
 
Join Date: Mar 2005
Location: Dallas area
Posts: 10,769
Default Your thinking was fine!

There's absolutely nothing wrong with thinking outside the box. You did the right thing by researching before you jumped in.
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RV-6 Flying since 1993 (sold)
<rvmel(at)icloud.com>
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  #12  
Old 06-14-2017, 12:15 PM
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Snowflake Snowflake is offline
 
Join Date: Oct 2009
Location: Victoria, BC, Canada
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I installed a fuel flow meter (red cube) in my aircraft, and now that i've used it I regret not installing two of them... One on each tank. I use an MGL gauge to read left and right levels (from the resisitive senders) and the fuel flow (from the red cube). Flow is used to show a total used number (which is combined for both tanks). The total used matches what I put in at the pump to within 1L out of a full tank. I only look at the levels as a rough guide, even after repeated calibrations and tweaking of set points I haven't managed to get them to read accurately (like, 3-4L off at some points).

Two flow meters would be mounted outside the tank, saving more volume inside for fuel. Less things to fail inside the tank, less holes through to the tank that might leak later, etc. etc.
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1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
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  #13  
Old 06-14-2017, 12:43 PM
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JonJay JonJay is offline
 
Join Date: Jan 2007
Location: Battleground
Posts: 4,348
Default

Quote:
Originally Posted by Snowflake View Post
I installed a fuel flow meter (red cube) in my aircraft, and now that i've used it I regret not installing two of them... One on each tank. I use an MGL gauge to read left and right levels (from the resisitive senders) and the fuel flow (from the red cube). Flow is used to show a total used number (which is combined for both tanks). The total used matches what I put in at the pump to within 1L out of a full tank. I only look at the levels as a rough guide, even after repeated calibrations and tweaking of set points I haven't managed to get them to read accurately (like, 3-4L off at some points).

Two flow meters would be mounted outside the tank, saving more volume inside for fuel. Less things to fail inside the tank, less holes through to the tank that might leak later, etc. etc.
Works great until it doesn't. i have had a fuel flow sender fail slowly. I discovered it while I was flying a long leg. My fuel level senders are amazingly accurate once they get off the top of the tank. I noticed the issue through my normal scan, checking my level against the totalizer. I have four fuel status relative checks - fuel totalizer - fuel level - clock and brain - and to a much lesser degree, fuel flow.
I wouldn't want to give up any of them.
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  #14  
Old 06-14-2017, 01:18 PM
Bevan Bevan is offline
 
Join Date: Sep 2007
Location: BC
Posts: 1,674
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Fuel level senders (one per tank) and a separate fuel totalizer system when used together are unbeatable in my opinion. Granted, the fuel level senders don't sense the top of the tank but that's not all that useful anyway. Sensing the bottom levels and comparing that to what the totalizer is telling you is useful.

Bevan
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  #15  
Old 06-14-2017, 01:46 PM
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larrynew larrynew is offline
 
Join Date: Oct 2007
Location: In New Braunfels, ist das Leben schön!
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I am extremely pleased with the accuracy of the stock Van's resistive system combined with Skyview's fuel flow totalizer. The red cube has been amazingly accurate and the resistive fuel measurement is a good gross confirmation that I don't have a leak in addition to also being accurate compared to the totalizer and refuel totals after they come off the top. I have more confidence in the fuel measurements in my RV than I did in the military or airlines.
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  #16  
Old 06-14-2017, 03:27 PM
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airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
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Quote:
Originally Posted by larrynew View Post
I am extremely pleased with the accuracy of the stock Van's resistive system combined with Skyview's fuel flow totalizer. The red cube has been amazingly accurate and the resistive fuel measurement is a good gross confirmation that I don't have a leak in addition to also being accurate compared to the totalizer and refuel totals after they come off the top. I have more confidence in the fuel measurements in my RV than I did in the military or airlines.
Same here. I started with capacitive senders in the tanks and had nothing but trouble with them, ended up going back to the standard resistive floats. My Red Cube totalizer is my primary fuel instrument though, with the resistive floats as a backup to guard against a leak somewhere before the totalizer. The resistive floats won't read the top 4 gallons in each tank and I really don't care anymore. I set the fuel computer to 36 gallons each time I top off, and it matches gallons pumped extremely well.
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  #17  
Old 06-14-2017, 09:04 PM
rapid_ascent rapid_ascent is offline
 
Join Date: Mar 2008
Location: Dublin, CA
Posts: 1,261
Default

Oh I was thinking one set was for inverted flight.
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  #18  
Old 06-14-2017, 11:19 PM
Evolution10 Evolution10 is offline
 
Join Date: Jun 2014
Location: oregon
Posts: 94
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I have duel senders in each tank - I used the senders provided by CIES (think Cirrus/Beechcraft among others). Works great and is incredibly accurate. I get readings all the way to empty. Never have I experienced any deviation in reading versus actual! Highly recommended.
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  #19  
Old 06-15-2017, 07:58 AM
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Larry DeCamp Larry DeCamp is offline
 
Join Date: Apr 2010
Location: Clinton, Indiana
Posts: 997
Default Another approach

Although resistive float senders are endorsed above, I read many negative comments in the archives about accuracy and reliability. In fact as installed, either the sender or the gauge didn't work. Yes, that could been resolved . But, I stripped them out and replaced them with simple optical sensors ( referenced here in archives) that trigger flashing lights with " yes/no" simplicity. I never leave the ground without measuring fuel levels and update the totalizer. The Red cube has been very accurate, two might be an enhancement but which one would you believe ? Then you look at your watch and flow rate for truth anyway. Bottom line, the low level sensor lights tell you accurately how much time is left in that tank or " don't land " on that tank if you have set the sensor low. I have set mine at about 2 1/2 gallon.
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Clinton, IN
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  #20  
Old 06-15-2017, 12:13 PM
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Sam Buchanan Sam Buchanan is offline
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Location: North Alabama
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Quote:
Originally Posted by Evolution10 View Post
I have duel senders in each tank - I used the senders provided by CIES (think Cirrus/Beechcraft among others). Works great and is incredibly accurate. I get readings all the way to empty. Never have I experienced any deviation in reading versus actual! Highly recommended.
The single sender will provide good readings all the way to empty. It is readings from full down to about 3-4 gallons burned where the single sender is not accurate. I have flown the EI dual digital fuel gauge with the standard senders in the RV-6 since 1999 and they have been very accurate except for the top three gallons.
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