Rudder/Brake Pedal Modifications

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Pedal Reinforcement
Several Kitfox owners have reported the rudder pedals cracking where the vertical tubes meet the horizontal ones in this picture.  This area needs to be reinforced to prevent this.  Here the areas have been roughened with skotchbrite pads and cleaned with denatured alcohol.
Here are the reinforcement castings which will reinforce the tubing junction.
Each casting needs to be ground precisely to size so it fits over its joint.  All the joints are slightly different due to the welds so a bit of time and care is required to do this.
Here the reinforcement castings have been epoxied in place.  After full cure, rivets were installed.  Note that only the casting shown on the left can have rivets placed in the horizontal tube.  If the horizontal tube on the right were riveted, it would prevent any rotation of the rudder pedals - not very useful. 

Pedal Bearing Replacement
The rudder pedal bearings, as designed, have quite a bit of friction in them.  The bearing block inside is plastic and when the nut shown is torqued to 25 in-lbs, the plastic bearing compresses and the rudder pedal sides are squished aginst the weldment causing a lot of friction. 
I decided to replace the squishy plastic bearings with 6061 aluminum.  Here I am turning the bearing, then I will bore it for the bolt with the drill at the right.
Here is the completed bearing.  It is twice as heavy as the plastic but will be much more reliable.
The bearing block protrudes slightly from the weldment so that then the pedal is tightened, it will not bind.  This also insures that the rotation will take place on the bearing surface and not anywhere along the bolt or nut which is important to insure that the nut stays on forever.  The bearings work amazingly well with almost zero friction and zero slop.  I love my lathe!
Here is the pedal installed with the new bearing, note the slight gap on each side which allows the pedal to rotate freely and insures that the nut will not experience any forces which might loosen it.

weldment bearings
The bearings on the outboard side of each weldment were about 3mils too large and had quite a bit of friction in them.  While I was redoing the rudder pedal assembly, I fixed this also on the lathe.
One of them could not be salvaged and had to be replaced with a brass one turned on the lathe.  Here the original plastic one is on the left and the one I turned on the right.
Here the brass bearing is in place.
 
Finally a front view of the retrofitted rudder pedal assemblies.

 

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