VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-12/RV-12iS
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 10-14-2019, 09:10 AM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 1,955
Default

Quote:
Originally Posted by psalys View Post
I'll try squeezing the left flapperon and see if the symptoms improve.
I did the flaperon trailing edge squeeze and wasn't happy with result. What works really good is to raise/lower entire flaperon with the rod end pivot bearings. Try 1/2 turn in/out and see if it affects heavy wing.
__________________
-
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 585

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
Reply With Quote
  #12  
Old 10-15-2019, 10:50 PM
psalys psalys is offline
 
Join Date: May 2017
Location: Eugene
Posts: 36
Default That's an interesting idea Jim

I had to get out my KAI to see what you were talking about.

Thanks for the suggestion.

Patrick
__________________
RV-12iS complete and flying
Reply With Quote
  #13  
Old 10-16-2019, 08:15 AM
rvbuilder2002's Avatar
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 8,929
Default

I always suggest people keep in mind that there are a lot off different things that can cause a roll imbalance.
Arbitrarily choosing one (adjusting rod ends) without investigating whether the adjustment they are about to make is actually causing the problem, may solve the problem, but only by inducing an additional problem the happens to counter the first one.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
Reply With Quote
  #14  
Old 10-19-2019, 04:38 AM
dwmillsap dwmillsap is offline
 
Join Date: Jul 2010
Location: Winterville NC
Posts: 38
Default

Adjusting the rod end bearings will start you chasing your tail. Ask me how I know. Haha.
Smashing the trailing edge of the flaperons will absolutely have an effect, but tread lightly because it takes very little to make a lot of difference especially the further outboard you are.
On my RV-12 I?ve noticed that it matters how much fuel is on board or whether or not I have a passenger or luggage (tools). So, be sure all of your observations are correct before you start changing things. These are great little aircraft so have fun!

Good luck.
__________________
Dennis W. Millsap
Retired Air Force
RV-6A built, flown and sold
RV-10 built, flown and sold
RV-12 built and currently flying
EAA Technical Counselor and Flight Advisor
A&P
Reply With Quote
  #15  
Old 10-19-2019, 02:41 PM
NinerBikes NinerBikes is offline
 
Join Date: Dec 2018
Location: Granada Hills
Posts: 697
Default

Quote:
Originally Posted by dwmillsap View Post
Adjusting the rod end bearings will start you chasing your tail. Ask me how I know. Haha.
Smashing the trailing edge of the flaperons will absolutely have an effect, but tread lightly because it takes very little to make a lot of difference especially the further outboard you are.
On my RV-12 I?ve noticed that it matters how much fuel is on board or whether or not I have a passenger or luggage (tools). So, be sure all of your observations are correct before you start changing things. These are great little aircraft so have fun!

Good luck.
/\ this, Absolutely. I can take my friends RV-12 while sitting in the passenger side at 255# to a heavy right wing, just by shifting my upper body over to the right 3 or 4 inches.
Reply With Quote
  #16  
Old 10-20-2019, 02:25 PM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 168
Default

Ditto what Dennis and Scott said. I'm a card caring member of the "chasing your tail club".

Changing any dimension of the control linkage is a risky and probably futile proposition. Changing push rod lengths (one side) only changes to relationship of stick position to neutral flaperon position, changing both sides only raises or lowers the flap positions at neutral. Then there are the interference issues: control stick interference with the nuts on the electrical cable run hold down block, push-rod interference with the electronic fuel pump. You might also end up with an over-center (or less than optimum) orientation of the flaperon torque tube arms. Changing the rodend bearings out on the flaperons to raise or lower them will certainly change something, but will also change the alignment of the flaperon with the torque tube attachment point.

I'd ensure all your dimensions are per plans, then focus on the trailing edge. Takes some patience. Some people have also had luck with ensuring the flatness of the top wing skin aft of the aft spar where it meets the flaperon.
__________________
Steve Morrow
RV-12 N12SM
Builder 121036
White Salmon, WA

2020 Donation Paid
Reply With Quote
  #17  
Old 10-20-2019, 03:15 PM
psalys psalys is offline
 
Join Date: May 2017
Location: Eugene
Posts: 36
Default Thanks for the suggestions

I have been checking and adjusting the flapperons and the upper wing skin trailing edge. Now the other wing (left) is slightly heavy and my right wing drop with stalls is much less severe. I will continue to make small adjustments and try to get it tuned just right.

Thank you all.

Patrick
__________________
RV-12iS complete and flying
Reply With Quote
  #18  
Old 10-20-2019, 09:30 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,752
Default

Try taping a piece of string to your canopy to act as a yaw string. If it is straight along the longitudinal axis and the ball is centered in flight it is rigged properly.

I wish I could claim I figured that out for myself, but my old CAP cadet friend became an F-4 pilot. He got his glider license in CAP and learned about yaw strings. When he had to test an F-4 out of maintenance he would tape one on the wind screen. He said they were good up to about 200 knots after which they were gone with the wind!
Reply With Quote
  #19  
Old 10-20-2019, 09:46 PM
RV8JD's Avatar
RV8JD RV8JD is offline
 
Join Date: Jan 2005
Posts: 845
Default

Quote:
Originally Posted by RFSchaller View Post
Try taping a piece of string to your canopy to act as a yaw string. If it is straight along the longitudinal axis and the ball is centered in flight it is rigged properly.

I wish I could claim I figured that out for myself, but my old CAP cadet friend became an F-4 pilot. He got his glider license in CAP and learned about yaw strings. When he had to test an F-4 out of maintenance he would tape one on the wind screen. He said they were good up to about 200 knots after which they were gone with the wind!
Yaw strings are used on virtually all sailplanes, and once in awhile you'll see one on a jet. But because of the propeller slipstream, they won't accurately work on tractor prop planes.

To coordinate, "Step on the ball, step away from the string!"
__________________
Carl N.
Arlington, WA (KAWO)
RV-8, 755 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflugel Standard Libelle 201B - Sold
Rolladen-Schneider LS1-f - No longer owned

Last edited by RV8JD : 10-20-2019 at 10:07 PM.
Reply With Quote
  #20  
Old 10-23-2019, 06:53 PM
Tacco Tacco is offline
 
Join Date: Jan 2017
Location: White Salmon, WA
Posts: 168
Default

Back to right wing drop upon stall: What are everyone's thoughts on the contribution of the landing light to the issue??
__________________
Steve Morrow
RV-12 N12SM
Builder 121036
White Salmon, WA

2020 Donation Paid
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 07:25 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.