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  #1  
Old 11-10-2022, 03:16 PM
bobnoffs bobnoffs is offline
 
Join Date: Jul 2012
Location: n. wi
Posts: 959
Default flaperon bearing adjustment

my right wing is heavy. i have been doing a lot of reading on how to correct it. there have been posts about turning in or out the flaperon bearing into its threaded receptacle . i have a couple questions....was the wing pulled out of the fuselege a couple inches so the flaperon could be disconnected from its linkage and since the inboard most bearing is fixed in its bracket wont moving the flaperon by adjusting mid and outboard bearings put a load on inboard bearing? finally. if mid and outboard bearings are adjusted the same amount won't that ''warp'' the flaperon? the more i read about this the more questions i have.
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Bob Noffs
n. wi.
dakota hawk/jab 3300 built and flying. sold 6/18.getting serious about the 12. in the hangar now as of 10/15/19
RV-12 kit as of 9/13
RV-12 airworthiness cert. 11/30/2021
first flight 7/25/2022
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  #2  
Old 11-11-2022, 12:55 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 2,820
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I purchased my RV-12 from the original builder with 48TT and it had a heavy right wing. I tried squeezing trailing edge of Flaperon and couldn’t discern any improvement. I lengthened / shortened the mid and outboard bearing rod-ends and achieved near perfect lateral balance. Airplane flies with ball centered in cruise flight. Airplane remains in lateral balance with full flap extension. Worked a charm….

I did not keep notes of the actual adjustments, but ended up lengthening on one wing and shortening on the other to minimize the deviation from spec. Wings were not pulled out of the fuselage to make adjustments. Simply remove the hinge pivot bolts and then twist the rod-ends. Have someone support the end of the Flaperon when making adjustment. If I remember correctly, none of the rod-ends were moved more than 1-1/2 turns. It took a few iterations to resolve the wing-heaviness. This work was done early-on and airplane now has > 800TT.
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Jim Stricker - EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 830

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father - CFI) - USAAF 1st Lt. Captain B-17H
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  #3  
Old 11-11-2022, 07:08 AM
thiggins thiggins is offline
 
Join Date: Mar 2020
Location: Saluda,NC
Posts: 151
Default

Quote:
Originally Posted by Piper J3 View Post
I purchased my RV-12 from the original builder with 48TT and it had a heavy right wing. I tried squeezing trailing edge of Flaperon and couldn’t discern any improvement. I lengthened / shortened the mid and outboard bearing rod-ends and achieved near perfect lateral balance. Airplane flies with ball centered in cruise flight. Airplane remains in lateral balance with full flap extension. Worked a charm….

I did not keep notes of the actual adjustments, but ended up lengthening on one wing and shortening on the other to minimize the deviation from spec. Wings were not pulled out of the fuselage to make adjustments. Simply remove the hinge pivot bolts and then twist the rod-ends. Have someone support the end of the Flaperon when making adjustment. If I remember correctly, none of the rod-ends were moved more than 1-1/2 turns. It took a few iterations to resolve the wing-heaviness. This work was done early-on and airplane now has > 800TT.
A question…the plans specify Loctite on the rod end threads. Did you Loctite them again? I’m guessing that’s done to prevent thread wear and loosening of the rod ends, since there were no jam nuts. Might be another question for Vans…
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Donation 2022 paid
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RV-12iS builder (Empennage complete, Wings complete!, Fuselage under way !, finish kit ordered, Garmin avionics ordered, engine ordered )
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Last edited by thiggins : 11-11-2022 at 07:39 AM.
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  #4  
Old 11-11-2022, 10:13 AM
todehnal todehnal is offline
 
Join Date: Jan 2005
Location: Kentucky Lakes area in KY
Posts: 1,000
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I have the exact same problem, and have also tried all of the tricks of squeezing and bumping trailing edges to no avail. I am ready to try the flaperon rod end adjustment. My thought is that lengthening the outboard rod end would add lift. So, if I would lengthen the outboard flaperon eye bolt on the right wing, do you think that would offer more right wing lift and stop the roll to the right?? I was planning to try one full turn ........Tom
__________________
2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold

Last edited by todehnal : 11-11-2022 at 10:15 AM.
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  #5  
Old 11-11-2022, 11:18 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
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Location: Hinckley, Ohio
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thiggins - I did not use add'l Loctite.

todehnal - Try one turn as you suggest. Write down changes you make. Test fly and then add or subtract. I can't tell you which side to lengthen and which side to shorten. Your first test flight will confirm improvement or add'l heaviness. That's why airplane is called experimental...
__________________
-
Jim Stricker - EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
Bought Flying RV-12 #120058 Oct 2015 with 48TT - Hobbs now 830

LSRM-A Certificate 2016 for RV-12 N633CM
Special Thanks... EJ Trucks - USN Crew Chief A-4 Skyhawk
MJ Stricker (Father - CFI) - USAAF 1st Lt. Captain B-17H
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  #6  
Old 11-11-2022, 11:51 AM
subpar_bucker subpar_bucker is offline
 
Join Date: Oct 2016
Location: Cranberry Twp, PA
Posts: 67
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This may or may not help you, but you might want to verify that the flaperon tubes match the specifications listed on 38iS/U-06. I drilled my flaperons after the rest of the airplane was assembled, so performing this check:

THIS DISTANCE
EQUAL FOR BOTH
ARMS PRIOR TO
MATCH-DRILLING
(STEPS 3 AND 4)

took me a while to figure out. Eventually I settled on using a caliper with an extension arm. I rested the fixed portion of the caliper on the top of the bolt and made sure the flat end of the extension arm was square to the bracket. The delta was 3 thousands. I haven't flown yet (soon), but I was encouraged that the delta here was so small.
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  #7  
Old 11-11-2022, 11:57 AM
todehnal todehnal is offline
 
Join Date: Jan 2005
Location: Kentucky Lakes area in KY
Posts: 1,000
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OK. I took one turn out on the right end and half a turn out in the center and test flew the airplane. It is a bit windy here today but as close as I can tell, there was little to no roll effect change. What I did notice was that the ball moved right. So I put it back until I can have smoother air to get a good test, or someone else has success with this approach. All that adjusting the length of that rod end does is to raise and lower the outboard end of the flaperon. After returning it to the original settings, I did some very accurate measurements, and to my amazement, both the left and the right flaperons measure almost exactly the same, in reference to the trailing edge of the wings. However, I still have a heavy right wing, even with half fuel and no passenger, as tested today. One more item worth mentioning. At full power, and an 80kt climb, I have very little roll tendency. When I pul back to cruise, the roll right tendency increases, requiring me to hold a little left stick pressure.....Tom
__________________
2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold
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  #8  
Old 11-11-2022, 12:03 PM
thiggins thiggins is offline
 
Join Date: Mar 2020
Location: Saluda,NC
Posts: 151
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Quote:
Originally Posted by Piper J3 View Post
thiggins - I did not use add'l Loctite.
...
I would contact Vans Aircraft directly and ask them if that’s ok.
I guess a good, and regular check of the security of the rod ends in the pivot brackets would be a great idea too. Turning them like we’re talking about here breaks the bond that the specified Loctite made at initial assembly. There’s probably a good reason they specify it.

__________________
Donation 2022 paid
ASEL INST COMM Tail-wheeler
RV-12iS builder (Empennage complete, Wings complete!, Fuselage under way !, finish kit ordered, Garmin avionics ordered, engine ordered )
https://eaabuilderslog.org/?blproject&proj=7buPHH99v

Last edited by thiggins : 11-11-2022 at 12:09 PM.
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  #9  
Old 11-11-2022, 01:29 PM
bobnoffs bobnoffs is offline
 
Join Date: Jul 2012
Location: n. wi
Posts: 959
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sooooo .......those who have adjusted the bearings are able to do it without sliding the wings out from the fuselege a couple inches?
__________________
Bob Noffs
n. wi.
dakota hawk/jab 3300 built and flying. sold 6/18.getting serious about the 12. in the hangar now as of 10/15/19
RV-12 kit as of 9/13
RV-12 airworthiness cert. 11/30/2021
first flight 7/25/2022
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  #10  
Old 11-11-2022, 01:48 PM
todehnal todehnal is offline
 
Join Date: Jan 2005
Location: Kentucky Lakes area in KY
Posts: 1,000
Default

Adjusting is simple. Remove the center and outboard bolts, slip the rod end out of the bracket and slide it back in after making your adjustment, then reinsert the bolts. Takes 5 minutes.
__________________
2013- RV12, Kit #119. N123M First flight Nov21. It's a keeper!
1998- RV-9 tail kit, built and sold
1989- RV-6 tail kit, built and sold
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