Worked on the elevator control linkage today. I wanted to finalize the settings and get this part finished. The manual calls for 28 degrees of up and down elevator plus or minus 2 degrees although they don't tell you how to do it. There are two push rods, a bell crank and four rod end bearings for adjustment. When I installed all these parts many months ago I just set them in place without any real adjustment. Now was the time to get it all set up correctly.
Initially, I wasted some time earlier in the week by trying to set up the linkages using what I thought would be center stick position. This is not how it is done. After much thought, I figured out that I needed to set the end positions first, as long as they are equal, it automatically sets the center stick position. So using my digital angle finder, I started by setting the 28 degrees down, then checked what the up position was. It was different. During several hours of trial and error, I eventually was able to get the linkages to give me 27.2 degrees up and down. I was very happy with that and called it a night.
HAPPY NEW YEAR!
Today, I rechecked the linkages and verified that I was getting the 27.2 degrees in both up and down elevator. I was. As part of this process I also had to set up the push rod for the pitch servo since it joins on the upper elevator push rod at the top of the bell crank. This push rod had to be adjusted so it would not contact the Garmin stops on the servo. Ideally, the stick should hit the physical stops in the fuselage before contacting the Garmin stops. So, you adjust the push rod linkage until you can achieve this. I was able to get it set up so there was about an eighth of an inch on either end of the throw before contacting the Garmin stops. Perfect.
It was time to tighten everything up, all the jam nuts on the rod end bearings. I used blue lock tight on all the rod end bearing jam nuts. Finished.
