<p>Gear’s are used for power transmission. There are various types of gears used for various purposes. Some various gears are as follows spur gears, helical gears, bevel gears, worm gear, etc. In this paper we are going to discuss briefly about the cycloidal gears and their future scope in the field of science. A cycloidal gear is mainly used to increase or decrease the speed. We are going to use it to decrease the speed while increasing the accuracy of the projectile. In this paper we are going to consider the cycloidal gears for the projectile of the missile. There can be of Single stage or multi-stage depending on the gear ratio that is required. After comparison with the other types of gearbox and speed reducers maximum reduction of gear ratio is achieved by cycloidal speed reducer</p>