whifof100ll
Well Known Member
Since new, I've always had a bit of fore aft play in the elevator controls of my 6. Perhaps about 1/16" at the stick tip. It has never been much of a bother but it is there. Today while checking on the integrity of my TT servo screws (which were fine) , I decided to look into the cause.
All of the play in the elevator system occurs by clearance at the brass bushing that resides inside the small tubes welded near the bottom of the sticks (W611 & W612). Some is caused by clearance between the brass bushing OD and the tube ID and some is between the AN-4 bolt and the bushing ID.
The plans were revised some time ago to change from a non-drilled bolt and nylock nut to a drilled bolt and casellated nut. This leads me to beleve that at one time people were cranking down on the bolt causing the U channel in W610 to clamp to the bushing making it not turn with aileron movement. The bushing would then wear against the ID of W611 & W612. The change would allow the bolt to be installed fairly loose. If the bushing and W611/612 tube ID fit were a tight tolerance the rotation would then between the bolt and the bushing. This is how I figured it should have been since it is easier to change a worn bolt than a worn stick tube. If the bolt is not very tight, my airplane has too much slop between the bushings W611 & W612 tube ID,s to ensure that the rotation occurs in one spot or the other. I did crank down on the bolts forcing the U channels to bite down on the bushing and eliminating one source of play. The control feel is much nicer and the play has goes from noticable to not noticable. The concern I have is that I may wear the ID of the chrome moly tube.
Does anybody know if it is a problem to have the bushing roll against the chrome moly tube ID? I suppose I could have new brass bushings made with tighter tolerances and leave the bolt looser since I am using a casellated nut.
Have others had fore aft play in the RV-6 and how did you resolve it.
All of the play in the elevator system occurs by clearance at the brass bushing that resides inside the small tubes welded near the bottom of the sticks (W611 & W612). Some is caused by clearance between the brass bushing OD and the tube ID and some is between the AN-4 bolt and the bushing ID.
The plans were revised some time ago to change from a non-drilled bolt and nylock nut to a drilled bolt and casellated nut. This leads me to beleve that at one time people were cranking down on the bolt causing the U channel in W610 to clamp to the bushing making it not turn with aileron movement. The bushing would then wear against the ID of W611 & W612. The change would allow the bolt to be installed fairly loose. If the bushing and W611/612 tube ID fit were a tight tolerance the rotation would then between the bolt and the bushing. This is how I figured it should have been since it is easier to change a worn bolt than a worn stick tube. If the bolt is not very tight, my airplane has too much slop between the bushings W611 & W612 tube ID,s to ensure that the rotation occurs in one spot or the other. I did crank down on the bolts forcing the U channels to bite down on the bushing and eliminating one source of play. The control feel is much nicer and the play has goes from noticable to not noticable. The concern I have is that I may wear the ID of the chrome moly tube.
Does anybody know if it is a problem to have the bushing roll against the chrome moly tube ID? I suppose I could have new brass bushings made with tighter tolerances and leave the bolt looser since I am using a casellated nut.
Have others had fore aft play in the RV-6 and how did you resolve it.
