Click here for a 26K JPEG.Note: This design only works with the older style points that have much easier to operate levers, more recent points from LEGOŽ seem to to have stiffer springs in them that are too hard for this point motor to operate.
Jeff Elliot has redesigned this point motor so that it works with
the new stiffer points, here are the LDraw instructions.
Inspiration for this project was sheer laziness, I hate to have to get up and walk over to the other side of a large layout to manually switch points. This point motor house can do it for you, provided you have long enough wires.
Unlike the crossover project, this one is pure LEGOŽ and doesn't require any cutting or drilling, all you need are standard bricks, a few Technic pieces and a 9V Technic motor and battery box.
The point motor mechanism is fairly simple. Two worm gears are mounted directly on the output shaft of the Technic motor and mesh with a 24 tooth gear wheel. On the same shaft of the gear wheel is a crank which connects to the point lever with a tie rod. This is fairly high gearing and operates very quickly so only a brief press of the button on the battery box is required to switch the point one way or the other.
When completed the unit fits over the yellow point switching lever. The small pin that sticks out of the side of the lever fits into the hole in the end of the tie rod.