More control mount and control stick work - 6 hours

Managed a pretty decent day in the garage. I was dreading cleaning up the cuts made in the control stick mounts. Basically the only way I could see doing it was to use good 'ol files. I clamped the pieces to the table and went to work. I was expecting it to take a long time since the aluminum was thick, but it goes extremely fast. I had everything done in just over a half of an hour. I took a little extra time to make sure that both pieces were equal and then I polished them.

I then fit the control stick cross member WD-610 to the mounts and found the correct combination of washers.






Next step that I wanted to do was fit all of the control stick pieces. This turned out to take a considerable amount of time and effort. All of the control pieces need a bit of work at the pivot point locations. The brass bushings do not fit nicely inside the control pivot points. They all need to be reamed. As well, the AN4-27 bolts do not fit nicely inside the bushings so the inside of the bushings need reamed as well. As it turns out, I don't have the proper sized reamers for this job. So I went old school on the task. Fortunately I have a good selection of drill bits and an endless supply of adhesive back sandpaper. I wrapped a small piece of 600 grit paper around a slightly smaller drill bit and used that to polish the inside of the control stick pivots.
 
 Working the pieces back and forth, stopping to check fit and redo many times till I was happy with the fit of the bushings and confirmed there was no binding. Next was to do the same to the bushings to allow good fitment of the AN4-27 bolts. Fortunately this process is quicker on brass than it is with steel.

After that The pieces are ready to assemble into the yokes of the WD-610 cross member. The plans have you grind the ends of the stick pivots and the bushings to allow a slip fit into WD-610. Using the exact same method used for the aileron pivots I trimmed down the bushing to the proper size. Again very tedious and time consuming work. In the end I had everything trimmed for a perfect fit an virtually zero play in the controls. Everything fits extremely well and no binding. I wanted to protect the exposed steel on the ends that were trimmed so I touched up with automotive touch-up paint that I have that is almost the same color as the Vans powder coating.


I want to be sure that I do not wreck the finish so I will give the paint 24 hours to dry before I assemble the sticks. Since I have a little time left, I moved on to countersinking the center section for the nut plates.
 
I had a difficult decision to make. The plans call for AD3-3.5 rivets to secure the nut plates however I have always been leery about countersinking too much. I'm terrified that I will go to far and end up having a "knife edged" hole that everyone wants to avoid. After much reading and discussing the matter with my buddy mike who is an experienced AME and builder. I've decided to use NAS1097 AD3 rivets on all the nut plates that are secured to thin aluminum. Anything thicker than 0.060" I will use the standard AD3 rivets.