A mechanism for precisely controlling a slide gate to provide certain and secure location of a sliding gate in a path of flowable dry bulk material, the mechanism including a rack and pinon gear with a shaft with a diameter hole therethrough for receiving a pin therethrough when the sliding gate is in a desired position. The swing arm is configured to inhibit removal of the pin and thereby prevent unwanted movement of the gate from the desired position. The swing arm is configured for selectively prohibiting accidental and/or intentional but unauthorized removal of the pin depending upon types of objects being placed through the open hole in the swing arm and the first fixed arm open hole.
