9g Servo Mount

This is a mounting bracket for a 9g servo motor for throwing model railway turnouts. Use 8mm M2 bolts and nuts to attach the motor to the mount.

Updated STL file added on 1 May 2021 for side access to mount the servo motor. Not all 9g servo motors are the same, some were hard to squeeze in.

It has a mount for a SPDT micro switch which can be used to flip frog polarity or any other purpose. The switch mount has slots for fine tuning its position. Use 12mm M2 bolts and nuts.

Use 1mm piano wire to throw the points. There is a pivot point (fulcrum) on the base.



My technique for installing is to first set the servo to a position somewhere near the middle of its range using a known pulse width (about 400), then attach the rotor perpendicular to the motor and then position the bracket in position for the piano wire to fit into the turnout. Once fitted, I adjust the PWM pulse width to find the limits for each throw direction such that the point blade firmly abuts the rail with