? Type of input electrical power (electrical motor, inner combustion engine with mechanical or hydraulic drive).
? Type of equipment to get driven.
? Amount of horsepower needed to supply suffi cient power towards the driven shaft.
? Full load speed in the quickest running shaft (rpm).
? Desired speed from the slow operating shaft ( or even the expected speed ratio). NOTE: If speeds are variable decide the horsepower to get transmitted at each pace.
? Diameters on the drive and driven shafts . . . This value may restrict the minimal amount of teeth for that sprockets.
? Center distance of the shafts.
? Note the place and any room limitations that may exist. Generally these limitations are over the greatest diameter of sprockets (this restricts the use of single strand chains) or even the width of your chain (this restricts using multi-strand chains).
? Conditions from the drive together with a determination in the class of load (uniform, moderate or heavy), significant operating temperatures or chemically aggressive environments should be mentioned.
Abbreviations Used in Equations
N Quantity of teeth on the large sprocket.
n Amount of teeth to the little sprocket.
R Pace in revolutions per minute (rpm) with the big sprocket.
r Pace in revolutions per minute (rpm) from the smaller sprocket.
C Shaft center 
distance in chain pitches.
HP Horsepower rating of the drive motor or engine.
KW Kilowatt power rating of drive motor or engine if using metric units.
SF Support Factor
