The first task of the day was to centre the servo actuator so that it was in the middle position. That way it will have maximum forward and back motion in the plane. To do this I used a 9V battery to measure the full in and full out position and moved the actuator to the middle position. With this done, we can install it in the elevator.
To install the trim tab servo we need to know where it goes on the rear skin. The plans show the exact location so I drew some lines to locate it.
This was a little nerve wracking as obviously if the servo rod didn’t line up with the bracket on the other side of the trim tab, there would be a problem. I extended the line all the way down and eyeballed it from the other side and it looked good enough to me, so I drilled the first hole, and then using the servo as a template, the other three holes.
Note that in this picture the actuator is pointing in the wrong direction but by placing it this way I can see that it is centred on the line. I opened the holes to size 30 and clecoed the servo inside the skin so that I could measure the servo rod length.
The servo rod has to be cut to size so I attached it to the servo, placed the trim tab so that it was at neutral position and made a mark on the rod where it met the attachment point on the bracket. Then it was some hot and sweaty action with the hacksaw. Sad to say I didn’t measure right the first time (fortunately in the right direction), but worked a charm the second time.
I was pleased to see that my rod was the same length as that suggested by the DVD.
I thought about being done for the day but the access panel cover was staring at me on the bench so I thought what the heck, and drilled it out for an A4 rivet.
Finally, I drilled all holes on the rear side of the skins to their final sizes, most to A4 but a few in the centre to A5.