A gear is a mechanical circular part with cut teeth or inserted hobs that joins with another gear with more/less number of teeth in order to increase/decrease the speed and force of the mechanism. The different number of teeth/cogs between gears is also called gear ratio, and it describes how the rotation mechanism performs. They are mostly used for any mechanical component that requires movement and they can be made of different materials. Nowadays, thanks to 3D printing, Mito3D has been able to collect most of the gears on the internet for you. Below you can check and download the best gear 3D printable models for free and for sale! Make you mechanical tool, instrument or toy alive by finding the best gear ratio!