You can easily calculate the speed when you know how to calculate a gear ratio. So, the equation is as follows:
Speed (Gear 1) * Teeth (Gear 1) = Speed (Gear X) * Teeth (Gear X).
When you assemble two gear wheels, their sizes determine the speed they will spin. Moreover, if the driving wheel is smaller than the driven wheel, it will rotate more than its component. This also means the driven wheel will spin fast if the driver wheel is larger.
Here is a step-by-step guide to calculating the gear ratio:
Step 1: Begin with a two-gear train. To determine a gear ratio, you must have two gears connected. It is called a gear train. The first gear is a driving gear attached to the motor shaft, and the second is a driven gear connected to the load shaft.
Step 2: Count the no. of teeth on the driving gear. An easy way to determine the gear ratio concerning two interlocking gears is to calculate the number of teeth they both have and compare them. You can count the number of teeth manually. However, check for this information labelled on the gear itself to refrain from manually calculating.
Step 3: Count the no. of teeth on the driven gear. Then, understand the number of teeth on the driven gear just as you did before for the driving gear.
Step 4: Now, divide one tooth count by another. As you know the number of teeth on each gear, you can determine a gear ratio easily. Divide the driven gear teeth by the driving gear teeth. You can count the no. of teeth on the driving and driven wheel and determine these numbers as a ratio or a fraction.
Follow this example to understand this calculation:
If a driving wheel has 20 teeth and a driven wheel has 40, evaluate the gear ratio as 40/20. It simplifies to 2/1 or 2:1. It means, for every rotation of the driven wheel, the driving wheel makes two spins. Similarly, a ratio of 1/2 means that the driven wheel spins twice for every rotation of the driving wheel. In other words, the driven wheel rotates faster than the motor shaft.