After a few experiments and unsuccessful attempts at building our own point throws for the outdoor G Scale railway, we settled on the simple system shown in these images.
The mechanism consists of a machined block of plastic, a brass pin with a small lever inserted into a threaded hole, and a spring (stainless) steel actuator rod. The actuator rod pulls/pushes an L‑shaped bracket that is directly attached to the sliding bar that the point blades are attached to.
There is a U‑shaped loop in the actuator rod designed to provide some “give” in the system and to ensure positive pressure is maintained on the point blades in both positions.
The design of these point throws has proven to be simple to build, easy to operate, and very rugged in an outdoor environment.