Processing...

`RPM_4 = ( RPM_1 * ( D_1 * D_3 ))/( D_2 * D_4 )`

Enter a value for all fields

The **RPMs of the 4 ^{th} pulley on 3 shafts** equation calculates the RPMs of a pulley when the RPM and Diameters are known for a series of pulleys on three axles (see diagram).

**INSTRUCTIONS:** Choose units and enter the following:

- (
**RPM**) RPMs of the first pulley._{1} - (
**D**) Diameter of the first pulley._{1} - (
**D**) Diameter of the second pulley._{2} - (
**D**) Diameter of the third pulley._{3} - (
**D**) Diameter of the fourth pulley._{4}

**RPMs of the 4 ^{th} Pulley on axle 3(RPM_{4}):** The calculator returns the Revolutions Per Minute. However, this can be automatically converted to compatible unit via the pull down menu..

The formula to compute the rotation rate of a fourth pulley on a three axle system is:

`RPM_4 = (RPM_1 * (D1 * D3))/(D2*D4)`

where:

- RPM
_{4}= Rotation on the fourth pulley on the third axle - RPM
_{1}= Rotation rate on the first axle - D1 = Diameter of first pulley on axle 1
- D2 = Diameter of second pulley on axle 2
- D3 = Diameter of third pulley also on axle 2
- D4 = Diameter of the fourth pulley