How Do You Size a Sheave

This is simple — lay the ruler’s edge across the center of the sheave and measure the diameter. With that measurement, you can calculate the ID by measuring the depth of the groove. Following the same example as before, suppose you measure 100mm across the sheave – that’s the OD.

How do you calculate sheave size?

To calculate the sheave ratio required, first divide the motor speed by the gear drive output speed to find the total ratio required. Select the nominal gear drive ratio that is closest to the total ratio required.

How is sheave wear measured?

To determine the amount of wear, place the proper size gauge in the sheave and shine a light behind the gauge. Light should not be detected between the gauge and the root of the groove. If wear is evident, the sheave should be re-machined or replaced (see Figure 2).