Back to The Machinist!
From the factory, the Kitfox rudder pedal hardware is unusable. The machinist made quick work of them!
Yesterday we spent about 4 hours working on rudder pedal bearings. (This is after we spent about a half day sanding the rudder torque tube) As expected, none of the black nylatron bearings fit in the rudder pedals. Part of the issue was bad powder coat job on the inside of the pedal assembly that resulted in corrosion. We spent about an hour fixing that.
The manual says to “file the bearings to fit”, whatever that means? Instead we attempted to reduce the outer diameter of the bearings using the factory recommended method: chucking the bearings in a drill and sanding them down as the drill turns. This method I find incredibly primitive and inaccurate. The method is basically a jerryrigged lathe with a hand drill and sand paper. But since these bearings were for the rudder pedals, and the rudder pedals don’t really rotate that much, I decided to give the method a try. After about 4 painful hours sanding, all the bearings had an acceptable fit.
As if the 4 hours wasn’t enough, I practically had to hammer the bolts in even after reaming, only to find that the bolts were not even remotely straight. As a result, the plastic bearings no longer fit. What a waste of time! We closed up the shop on a bad note.
The next morning, the whole rudder pedal assembly was in the machine shop. A couple hours later, as expected, the hardware came out as a perfect fit! Machinist’s notes:
So, the ½ Nylatron bushings needed both the OD reduced and the ID enlarged in order to get the proper fit.
Turns out the bolts not being straight were only part of the problem. The hole was not centered throughout the entire length.
When a part like this must be drilled from each end, it is important that both are centered precisely.
It is not uncommon for a drill to drift off center in a long hole, but when not centered well from the start, there is no chance things will meet properly in the middle. So, the bent bolts magnified this problem.
Had to remove 0.007 - .010” off the OD of the other bushings.
Took longer than I anticipated, but things are done.
He not only had to STRAIGHTEN MY BOLTS for me, but he also had to effectively re-manufacture the bearings. How is an average kit-builder supposed to handle these issues? As you may be able to tell, I am pretty frustrated with the kit. My faithful building assistant had an interesting quote today. He said, “ this kit is full of dog work.” I get that these kits require some above and beyond work, but they are effectively asking you to own your own machine shop.
For those of you out there building, I hope you are able to find a patient and talented machinist nearby. For those of you thinking about building, find a machinist nearby before you start!
