This is a collection of various mechanical calculators which are useful while designing. These can help with determining gear ratios, gear center to centers, belt center to centers, chain lengths, and much more.
West Coast Products Calculators
Used to determine the center distance between two gears of any given size. Can be done for either main type of gear used in FRC (20DP & 32DP).
Used to determine center to center distance for given pulleys. This calculator will only given you belt sizes which are sold by VexPro. Because belts come in specific sizes the calculator will show you the two closest sizes to your desired center distance.