This is the steering and trim control for the hovercraft I'm building (in the personal projects forum).
It's make from 3/4" conduit.
There are two pieces of 2 x 3 x 3/16 steel on the front end. That is used to mount the control stick. (A stick is in place temporarily for the picture, but will be bolted in.)
At the back there is a peice of 2 x 12 x 3/16". It is used to mount the steering cables. The 12" bar is needed so that a small motion of the stick will result is a larger motion of the control cables for the rudders.
When it's mounted in the hovercraft I'll figure out how long the control stick needs to be. It will only mount with a single bolt so that it can be pushed forward and pulled back. Part of the stick will go below the main body of the steering arm. It will have an eye-bolt on it. A cable will attached to it to control a trim wing.
The more power you apply, the more the nose of the craft wants to go down. So, as you pick up speed, you pull back on the stick to cause the trim wing to go up and counter the nose-down tendency.