? Type of input electrical power (electric motor, inner combustion engine with mechanical or hydraulic drive).
? Type of gear for being driven.
? Amount of horsepower necessary to provide suffi cient electrical power to the driven shaft.
? Full load velocity in the fastest operating shaft (rpm).
? Desired speed in the slow running shaft ( or even the required velocity ratio). NOTE: If speeds are variable figure out the horsepower to get transmitted at every speed.
? Diameters in the drive and driven shafts . . . This value may well restrict the minimum amount of teeth to the sprockets.
? Center distance in the shafts.
? Note the position and any area limitations that may exist. Generally these limitations are about the highest diameter of sprockets (this restricts the usage of single strand chains) or the width of the chain (this restricts using multi-strand chains).
? Conditions in the drive together with a determination of the class of load (uniform, moderate or heavy), serious operating temperatures or chemically aggressive environments should be mentioned.
Abbreviations Used in Equations
N Quantity of teeth around the massive sprocket.
n Variety of 
teeth over the tiny sprocket.
R Velocity in revolutions per minute (rpm) of your significant sprocket.
r Speed in revolutions per minute (rpm) from the tiny sprocket.
C Shaft center distance in chain pitches.
HP Horsepower rating of your drive motor or engine.
KW Kilowatt electrical power rating of drive motor or engine if using metric units.
SF Service Factor
