I managed to do a fair amount of progress on the center section bulkhead today. First, I noticed I still needed to make a couple of snap-bushing holes for wiring in the bulkhead frames. There was no pilot holes for these, so I measured out and pilot drilled the holes in the first frame, then used a sheet of aluminium to trace these pilot holes to the other frame.
All four holes drilled…
Next I countersank the bulkhead flange rivet holes.
After that I dug out the control column bracket, measured out the top holes and drilled them.
Then I bolted them to the bulkhead spar, and squared them to the spar flanges.
With the brackets firmly tightened and squared to the spar, I could use the spar as guide to back-drill the lower holes. Here they have been drilled, and temporary bolted to the spar. (I intentionally used short bolts, so they didn’t touch to nylon lock in the nuts.)
Now it was time to arrange the flight sticks. They come with brass bushings that have to be drilled up to ¼”, then adjusted in lenght to fit in the bellcrank openings. The lenght is easily adjusted by putting the bushing in the drill press, then pulling it down onto a file resting on the drill table. I’m sorry, I forgot to take pictured while I did all this.. I will try and take some later to explain.
Next small project, was to make two spacers out of this piece of tubing.
They had to be exactly 1.438″
I used the same procedure as with the control stick bushings.
The spacers installed. I had to enlarge the holes of one of the frames to ¼”, I did this by aligning the two spars by inserting the wing bolts, then using the other spar as drill guide. Worked pretty good!
Last thing I did today, was to mark the area of the control stick bellcrank brackets, that will be removed for weight savings. I am looking for a bandsaw at the moment, it would make jobs like these a lot easier…