As you are aware, as the Wand moves aft, the Foil-Push-Rod moves down, pushing the trim-tab on the Front Foil down.
[animated overall drawing should be here instead, eventually, maybe ... ]
The way this works:
The Wand is inserted into the Fwd-Pivot-Block. This pivot block rotates around a 1½” x ¼” clevis pin, and has a range of motion of 75º (limited by the housing). As the Wand goes aft, the Fwd-Pivot-Block rotates clockwise, as viewed from the Port side.
The Foil-Push-Rod is connected to an Aft-Pivot-Block that also rotates around a 1½” x ¼” clevis pin, and the upper range of motion is limited. As the Wand goes aft, the Aft-Pivot-Block rotates counter-clockwise, as viewed from the Port side.
Internal to the “Wand-Box” is an intermediate horizontal Carbon-Push-Rod with 10-32 male threads on each end. It connects to the Fwd-Pivot-Block and the Aft-Pivot-Block. The rotating arm of the Fwd-Pivot-Block is ⅝”, and the Aft-Pivot-Block is 15/16”. The 75º rotation of the front yields 40.7º aft rotation. The vertical Foil-Push-Rod is also connected to the Aft-Pivot-Block with an offset of 11/16”.
[Simplified drawing should go here]
At rest, the shock cord pulls the Wand all the way counter-clockwise raising the Foil-Push-Rod up. Rotating the Wand 75º will push the rod down down from its initial height.
The maximim up-down range of the Foil-Push-Rod is 0.451” with the Aft-Pivit-Block and Fwd-Pivot-Block fully rotated clockwise and counter-clockwise.
If the length of the Carbon-Push-Rod is shortened, the initial height of the Foil-Push-Rod is lowered, and its maximum range will be reduced slightly. Each turn of the threads of the Carbon-Push-Rod is 1/32nd of an inch (0.031") off the pushrod, which will lower the Foil-Push-Rod .023".