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  #21  
Old 12-06-2018, 11:35 AM
Tom Martin Tom Martin is offline
 
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Location: Ontario, Canada
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Scott is absolutely correct. I had been in the shop thinking about your issue and it occurred to me that a slight twist in one or more of the control surfaces could also cause a trim imbalance.
Two things to try. Line up the surfaces on both wings and pull a string from the inboard flap end and extend it out to the outboard edge of the wing tip. This should show any twists in a surface. Check both wings at the same time so that you can compare side to side.

Another option is to clamp a long piece of angle to the surfaces and see if everything is lined up. It would not take much of a twist in an aileron to make a difference in flight.
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  #22  
Old 12-06-2018, 11:55 AM
Bavafa Bavafa is offline
 
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Location: Sacramento, CA
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Thank you both Tom and Scott for the additional info.

As part of my re-checking the rigging, I checked for twist in both flaps and aileron. Not an easy thing to check but this is what I observed using digital level and looking straight thru the trailing edge of aileron/flap.

The digital level showed minimum twist (it was fraction of a degree) and it varied as measured at different part of the flap. I mostly accounted for that as part of variation in the skin deflection but there was no appreciable change from the extreme inboard to extreme outboard and this was true for both sides.

My left flap can go slightly higher than the right side before it hits the stops. I have adjusted the left to be at the same level as the right when it is fully retracted and it is only the thickness of a paper lower than aileron at neutral position. I had not checked for the elevator position when I was checking these.

One thing I need to check to see if I have the newer jig with the reflex hole which is noted in the manual or the older style. It seems it should not matter since both L&R were used using the same jig but nevertheless.

Finally, I might just need to stop being anal about it as the heavy wing is within the trim margin, but if I could get it to fly straight with the trim in the middle, that would be awesome.
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  #23  
Old 12-06-2018, 12:12 PM
DavidAhrens DavidAhrens is offline
 
Join Date: Feb 2007
Location: Bakersfield, CA
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I don't know the differences between the 14 and the other RVs but I like to connect the aileron trim system "after" I have flown the plane to confirm everything is OK. This way I can be sure the trim system is not bias one way or the other.
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  #24  
Old 12-06-2018, 03:44 PM
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Champ Champ is offline
 
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Location: Kingsville, Ontario, Canada
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My right wing was also slightly heavy but within trim range. Used my caliper to measure the aileron thickness half an inch from the trailing edge at each rib and found the left wing to be 34 thou thicker on average than the right. Squeezed the left side down at the thicker rib locations and it corrected the heavy wing.
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Last edited by Champ : 12-07-2018 at 12:55 PM. Reason: Typo
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  #25  
Old 12-06-2018, 04:03 PM
Bavafa Bavafa is offline
 
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Quote:
Originally Posted by Champ View Post
My right wing was also slightly heavy but within trim range. Used my caliber to measure the aileron thickness half an inch from the trailing edge at each rib and found the left wing to be 34 thou thicker on average than the right. Squeezed the left side down at the thicker rib locations and it corrected the heavy wing.
Yes, squeezing the trailing edge is a very effective way of addressing the heavy wing but this is mostly on the model that has a bend trailing edge as oppose to riveted ones.
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