Rudder Rod Ends

[patrick.hvac]

Hello!

I was working on the rudder recently (airfoiled SS7) and I would like to ask if people can comment on fitment of the rod ends.

I've scoured build threads and see some builds have up to half of the threads exposed on the bottom mount. I checked a model 5 and its bottomed out top and bottom.
Looking at the Aurora Bearing site and FAA guides I can't find anything on an acceptable amount of thread engagement.
I see the 1.1/2-2.5/16" gap callout and I know the design intent is a 1/8" gap. Just curious on how much others have extended the rod end to achieve it.
My tail post is not factory so I don't have a baseline to judge. I feel good about the engagement of mine but if there is a standard I want to make sure that I meet it.
Input is appreciated.
Thanks!

[109JB]

General rule of thumb is 1.5 times the major diameter of the thread. If I remember those are 5/16 rode ends which would mean about 1/2" engagement. However that rule of thumb is for radial loading of the rod end to its maximum load rating, which is nowhere close to what they will see as a rudder hinge, so you could get away with less. I'd definitely like to see at least 1 diameter or 5/16"

[jiott]

I believe the rod ends (female thread) have a small hole in the side to indicate the mating male thread must at a minimum come to the hole to achieve full load rating.