http://youtu.be/5q-BH-tvxEg Each worm/worm gear pair reduces the speed of the motor by 1/50th. Since there are 12 pairs of gears, the final speed reduction is calculated by (1/50)12. The implications are quite large. With the motor turning around 200 revolutions per minute, it will take well over two trillion years before the final gear makes but one turn. Given the truth of this situation, it is possible to do anything at all with the final gear, even embed it in concrete.