G scale points motor

thingiverse

Here I designed a points motor for LGB turnouts. Other g-scale brands might work too. It is mountable with all turnouts on both sides of course. The assembly of the thing is quite easy: Cleanup all the parts from errors if your printer is not that precise. At least i have to do this step... To mount the pinion on the servo i use a hot air soldering iron to warm up the inner of the pinion and then press it on to the Servo. With this technique the outer part of the pinion won't get deformed. Alternative 1: you can try to drill the hole a tiny bit undersized and press it on the servo with Force. Alternative 2: Superglue but this can have disadvantages if you have to adjust ;-) Then try to dry fit all the parts without the spring. They should all move freely however not too slack so they won't disengage. The two levers are screwed down with a M3x10 screw an a washer. If everything's fine you can use some grease on all moving parts while assembling everything. While testing, hold down the servo as it tries to move upwards and will disengage the pinion from the rack. Maybe you end up with the mechanics only working in one direction. Then you have to adjust the pinion on the servo or move a gear tooth further. A servo tester is quite helpful on this step. I use quite cheap 9g servos as seen on the images to drive the mechanic. got them from amazon if you wonder. The Spring is made from 0.7mm spring steel wire. I bend the wire of a simple tension spring with the right diameter. The length of the arms should be around 10-12mm. See the bend pattern in the images.