1. Introduction (Gear Boxes)

This project was inspired by a review of gear boxes and transmission systems. The goal of a gear box is to provide an amplification ratio between the speed/torque at the input and output shafts. Multiple speeds in a gear box allow the operator to change the speed/torque ratio depending on necessity in the application. For this project, a manual transmission with a sliding mesh (unsynchronized system) was designed and fabricated. Such a system is one of the simpler methods to design a gear box with multiple speeds. An example of a cardboard gear box with a sliding mesh can be found here. The image below also shows a sliding mesh gear box, albeit with a slightly different setup from the one used in this project. 

While a sliding mesh transmission system is relatively simple, it is outdated now due to the use of better systems such as constant mesh manual transmissions, automatic transmissions, continuously variable transmissions (CVTs), and others. Some examples are shown below. 

Of course, gear boxes and transmission systems have many applications. The image below shows a 5 speed + reverse gear box from a Volkswagon. Other applications include bicycles, industrial machinery, robotics, etc.