Decided to get the servos mounted in the Horiz. Stab. As shown earlier, I added a bit of glue and the rib that mounts the servo now seems strong enough for the task. I wanted to get the servo as close to the skin as I could to minimize the servo arm length. First step is to get the wire threaded into the hole. By making a bend in the wire and orienting the plug I was able to fish it in there, then grab it with a needle nose pliers.
Here's a photo showing the inside of the wing, and wire routing through the hole.
I positioned the servo onto the mount, then used a fine drill bit in a pin vise to drill the hole for the servo screw. I oriented the servo so the output shaft would be farthest from the control surface to minimize alignment angles.
I drilled one, put in a screw, then drilled the next, put in the screw, until all four are done. My servo arm center was right about on the top of the servo output shaft, so I knew that I could measure to the shaft to determine where the slot would be. I used a stick to measure and marked the slot location. I did the initial cut with a dremel wheel, then filed it to get the right alignment and shape for the slot. It had to be wide enough to allow the servo horn to be dropped in and mounted.
I centered the servo with my Hitec programmer, and mounted the servo arm. Check for movement to make sure the slot is shaped correctly.
I decided to use some 4-40 hardware I had, but as mentioned earlier I think the stock hardware would be up to the task. It would even be a bit lighter than what I used.
Even using the far outside hole on the control horn I was able to easily exceed the 30mm recommended travel for the elevator.
I should have some time soon to get back to the wing and get the servos and retracts mounted.