Anti-Servo/Trim Tab

Dec 2002

The hinges had to be shaved off slightly to fit inside the leading edge Vee	The tabs were taped to the tailplane for a snug fit. While drilling, the hinge flange was held with a tiny screwdriver through the hinge slots. To allow free movement of the tab, the gap between the tab and the tailplane had to be expanded by lightly sanding the flanges.
The drive pins were drilled to provide a key for the bonding. This required some heavy drilling and dulled drill bits since these are steel plates. It turns out that these are the older plates prior to mod 58. The new plates are 1/10" thick instead of 1/16". Waiting for replacement from Europa.

April 2004

Did not do any building for a year and a half. We moved to a new home and I had to build a whole new workshop. It was an old garage more than 50 years old, and lots of things had to be done to it.

The new drive pins were drilled out again. Used a cobalt drill bit which made the task a whole lot easier than last time

The manual recommended procedure for aligning the trim tab drive pins did not appear to be convincing. Other builders had to remove the pins and rebond several times to get the alignment right. This task would be a lot easier if the drive pins are installed after assembling the tailplane (see next chapter). The T-bar (TS05) and the bushings (TS03) were installed and the drive pins were positioned such that both trim tabs were perfectly level with the elevator while the T-bar sits in the center slot of the torque tube. This exercise made it evident why so many builders had trouble with this part. Even if the drive pins were off by 1mm (which is hard to tell by visual alignment), one trim tab will end up being higher than the other.

The drive pins had to be ground a little bit to make it fit inside the trim tab.