Control Column Chaos

[Avid Randy 50]

I don't even know where to start....other than I have been working on this control column for hours and hours and hours trying to get it to fit properly to then drill holes to mount it.  It seems no matter what I do it just will not work completely free as it should.  I am so aggravated that I am pulling my hair out and  ready to just cut, grind, bend, pry, pull etc. to get this thing to work right!  (Hopefully not!) 

First off, the control stick connecting link inside the control column is too long.  When  the rod ends F-38 are screwed on the whole way the stick pivot sockets still angle inward towards each other.  I guess I'm going to have to cut off some of the threads to shorten the rod/link so things will square up properly.  Has anyone had to do this during there build?

Then the tabs for the mounting of the F11 control column bracket were welded too high on the cross bar so I had bent them down some and straightened them back out so that it is close to the height of the pass side tabs.  Because of this I added an extra piece of ply under column end bracket so that the control column would be rather level otherwise the bellcrank u-joint would not even fit into the end of the control column.  Figured once I know everything is fitting well I can make a new control column end bracket that is at the correct height to accommodate this.

After getting the control column level the bellcrank u-joint still strikes the bottom of the control column when entering the end.  The screw head grinds into the bottom.  I can adjust things at  times so that in the neutral and aft positions it will work freely but when moving stick forward the u-joint binds on the bottom.  Also at the same time with stick forward and to the left the F-38 rod end shoulder binds against the bottom of the stick pivot socket as seen in the photo.  It works fine to the right.

Reading AD #04 advises to reduce bushing thickness of the stick pivot socket forward or aft to help with alignment.  Probably have to grind the front bushing down so pivot socket moves forward and place washers aft to help with the rod end shoulder binding.  With the u-joint binding , it seems the front aileron bellcrank is too low so I was thinking of doing the same thing as the pivot sockets.  Grind some of the upper part of the bellcrank pivot bushing off and place washers below it which would help raise the bellcrank an 1/8" or so and hopefully allow the u-joing to move freely in and out of the control column.

Just wanted to reach out and see what you guys think about this and if any of you have had problems like this before I go doing something drastic and make deviations/changes that can not be reversed.  Thanks for any info/input.....Cheers Randy

 

[FredStork 453]

Hi Randy! 

I don't say this is the problem but I noticed a difference between your and my setup. Compare your second last photo with this one:

[TJay 1041]

I'm with Fred on this one. I know Kitfox had an AD to remove it from the front and place it on the rear but no matter what way I tried mine would bind and would for sure bent the rod end. So I installed it on the front anyway I shove the stick I can wiggle the rod end with my fingers. As far as hitting the bottom the easy fix is file a little material off the top of that red control arm where it meets the seat truss and put a washer under it. That should raise it up a bit . And the inside you should easily be able to shorten the rod and re tap the inside of the tube. By the way that is a really nice paint job.

[Avid Randy 50]

I'm with Fred on this one. I know Kitfox had an AD to remove it from the front and place it on the rear but no matter what way I tried mine would bind and would for sure bent the rod end. So I installed it on the front anyway I shove the stick I can wiggle the rod end with my fingers. As far as hitting the bottom the easy fix is file a little material off the top of that red control arm where it meets the seat truss and put a washer under it. That should raise it up a bit . And the inside you should easily be able to shorten the rod and re tap the inside of the tube. By the way that is a really nice paint job.

 

Fred/TJay - Thanks for the input on moving the control link to the rear.  I did try that and did not have much luck either but I think I'm going to fix the other issues first and see where this binding ends up at that point.

TJay - Sounds like we are on the same idea.  That's what I was looking at doing removing some from the top of the pivot point and place a washer or two under to raise it up a bit.  I would never have imagined that the control ink would have been too long but it had me baffled looking at it as the sticks were pointing at each other and the rod ends were bottomed out on the threads.  I think I'm going to shorten the control link and raise the bellcrank first and see how that all works out.  Then revisit the binding of the rod end as maybe some of this will help.  As far as the paint - Thanks but I really can't take credit for that as I had all the parts powder coated and they really turned out Well!  Also nice looking Bird you have....Glad to see it all coming together!  Congrats on the Inspection too!  Has to be a little sigh of Relief?  Cheers Randy

[akflyer 1427]

You can also take a little material off the bottom of the control column and clearance it..

 

[Avid Randy 50]

Finally FREE!!!  Not without a lot of aggravation though!  I first started by shortening the connecting link to get control sticks to be parallel with each other and low and behold now the controls bind side to side!  Had not been prior to shortening!  I was flipping MAD after all of this!  Well shortening the link (which needed to be done) now created sharper angles when moving side to side and the same thing that was happening at the bellcrank now was happening at control stick.  The rod bearing shoulders were binding against the lower part of the pivot sockets.  At this point I was ready to throw the whole mechanism in the trash and call for a new one!  I finally grinded of the corners of the shoulders that were binding on all rod end bearings, added a washer between u-joint and bellcrank to allow it to move more freely, grinded off the top of the bellcrank pivot point and placed two washers underneath to raise it an 1/8" or so.  This helped all together to finally have FREE controls!!!  Thanks for all your input!!

Yeah.....that lasted real long!  Then I installed the elevator control rod and it is so stiff that truly I think I could possibly break the control column if I would attempt to mess around with it that way.  Has anyone had a very stiff elevator control rod?  The bushings were drilled out to 9/16" as directed.  Would it be OK to drill out the first 2 or so bushings to 5/8" to help reduce the friction through the bushings?  That's my only thought of correcting it at this point.  I just don't know how critical it is to have the rod tight in the bushings.  Just seems to be more of a guide than anything else.  Again just figured I would see what you guys think before I may do something that would not be wise or maybe you have a better idea/way.

[Avid Randy 50]

All controls nice and Free now!  I did drill out first elevator control rod bushing to 5/8" which allowed a nice smooth glide through the rest of the bushings.  It seems the first bracket might be welded at an opposing angle to the way the rod goes and this caused it to bind more in that bushing.  Not sure but works much better now.

Found this friendly feller watching over my garage for me this weekend!

[Ramos 62]

Hmmm, that ain't no feller. There was a feller but he was killed and eaten by the gal in the picture.

[Avid Randy 50]

Yeah...I should've said Ms. Feisty!