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  #21  
Old 05-22-2018, 12:44 PM
Tom Martin Tom Martin is offline
 
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Scott, I never did test the difference between the "0" setting and the -3 or reflex setting. I can understand how it would climb a bit better in the "0" but what is the actual climb difference in feet per minute?
The climb is so good in the reflex position, even at gross weight that I wonder it is worth the bother. There is also the opportunity to forget to go to reflux at cruise, not that I ever forget to flip a switch....
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  #22  
Old 05-22-2018, 01:13 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Tom Martin View Post
Scott, I never did test the difference between the "0" setting and the -3 or reflex setting. I can understand how it would climb a bit better in the "0" but what is the actual climb difference in feet per minute?
The climb is so good in the reflex position, even at gross weight that I wonder it is worth the bother. There is also the opportunity to forget to go to reflux at cruise, not that I ever forget to flip a switch....
I can't remember the amount of difference testing showed.
Perhaps Steve (airfoil designer and RV-8 owner here on VAF) would comment on what the theoretical difference is.
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  #23  
Old 05-22-2018, 01:14 PM
BobTurner BobTurner is offline
 
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I have actually wondered about the opposite question: Is there a density altitude, above which true airspeed is higher with zero deg flaps? I did some experimenting around 16,000 DA (iirc) and couldnít detect any difference. But it wasnít perfectly smooth at the time.

A scond question for Scott: my 2009 rv10 kit came with a max speed limitation for zero flaps. Has that been removed from newer kits? Do I need any upgraded parts to remove the limitation?
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  #24  
Old 05-23-2018, 06:56 AM
n982sx n982sx is offline
 
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Quote:
Originally Posted by bkervaski View Post
I'd love to know what your -3 and 0 voltages are set to in the calibration.
Here they are.

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  #25  
Old 05-23-2018, 09:17 AM
Bavafa Bavafa is offline
 
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Quote:
Originally Posted by n982sx View Post
Here they are.

Can't view it and I would like to know how this is setup as it won't be long before I need to do this.
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  #26  
Old 05-23-2018, 09:28 AM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by BobTurner View Post
my 2009 rv10 kit came with a max speed limitation for zero flaps. Has that been removed from newer kits? Do I need any upgraded parts to remove the limitation?
Nothing has changed

That is why in my description of how we operate the airplanes I mentioned that we climb at the zero flap setting, cruise and descend at the -3 setting, and then revert back to zero when slowing for pattern entry.
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  #27  
Old 05-23-2018, 11:02 AM
KeithB KeithB is online now
 
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My understanding (and I could be completely wrong), is that reflex helps take some load and trim off the tail, particularly with lighter loading = forward CG. With higher and aft loading, it is less beneficial. In certain circumstances, I have seen a 3 knot improvement at cruise going from trail to reflex position on flaps. In other circumstances, Iíve seen negligible effect.

Like others have posted, I use trail for takeoff and climb, and during maneuvers such as instrument approaches - otherwise reflex.
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  #28  
Old 05-23-2018, 12:37 PM
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bkervaski bkervaski is offline
 
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@n982sx Thank you! It appears your voltages are scaled opposite mine. I looked online at some other screenshots of the calibration screen and they line up with yours. So, it appears, I may have two wires swapped on the POS-12.
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  #29  
Old 05-23-2018, 12:51 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by KeithB View Post
My understanding (and I could be completely wrong), is that reflex helps take some load and trim off the tail, particularly with lighter loading = forward CG.
No.
It is like I already said, its specific to the airfoil design and a reduction in induced drag.

Otherwise it would be beneficial to all the RV's, regardless of what model.
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  #30  
Old 05-23-2018, 09:52 PM
n982sx n982sx is offline
 
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Quote:
Originally Posted by bkervaski View Post
@n982sx Thank you! It appears your voltages are scaled opposite mine.
I should have mentioned that I swapped the wires from the sensor to reverse the slope of the voltage line. I also had to swap the the GAD 27 flap wire control wires.

The GAD 27 software seems to think that the signal voltage will always drop as the flaps come down. This is not true with the installation of the POS 12 per Vans RV 14 installation. This is really a software problem fixed via hardware. Nothing wrong with the Van's installation or the POS 12.
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