Useful Formulas

Torque
T=Force * Radius T (Lb.In.)=Hp * 63000/N T (Lb.Ft.)=Hp * 5250/N	Hp=Horsepower N=Revolutions per Minute
Dynamic Torque (Lb.In.)
Clutch = {(Wk2 * N * 12)/308ta) + TL} * 1/E Brake = {(Wk2 * N * 12)/308td) + TL} * E	Wk2 = Inertia (Lb.Ft.2) N = Change in RPM ta = Accel time (Sec.) td = Decel. time (Sec.) TL = Load Torque E = Efficiency
Horsepower
Hp = T * N/63000 Hp = T * N/5250	T = Torque (Lb.In. N = Revolutions per Minute T = Torque (Lb.Ft.) N = Revolutions per minute
Thermal Energy per Engagement
Clutch = TEc = 1.7 * Wk2 * ([N2-N1)/100]2 * Tdc/(Tdc-TL) Brake = TEb = 1.7 * Wk2 * (N1/100)2 - (N2/100)2 * Tdc/(Tdc-TL)	WK2 = Inertia (Lb.Ft.2) N1 = Beginning Speed N2 = Final Speed TDc - Dynamic Torque (Clutch) TDb = Dynamic Torque (Brake) TL = Load Torque
Average Thermal Horsepower
THP = {(TEc + TEb) * CPM}/33,000	TEc = Thermal Energy (Clutch) TEb = Thermal Energy (Brake) CPM = Cycles per Minute
Horsepower Sec. per Min.
Hp Sec./Min. = (TEb * CPM)/550	TEb = Thermal Energy (Brake)
WK2 Inertia
Concentrated Weight WK2 = WR2 Translating Weight WK2 = WR2	W = Weight (Lbs.) R = Radius (Inches)
Uniform disc WK2 = {(¶D2/4) * L * Lb.In.3} * (R2/2)	D = Diameter in In. L = Length in In. R = Radius in In.
Hollow Cylinder WK2 = {¶ {[(Do2-Di2)/4] * L * Lb.In.3} * (Ro2 + Ri2)/2	Do = Outside Diameter (Ins.) Di = Inside Diameter (Ins.) Ro = Outside Radius (Ins.) Ri = Inside Radius (Ins.) L = Length

Conversions

English-Metric Conversions  Useful Formulas  Inertia  Motor Formulas  Motor Information

Multiply the Base Unit by the Factor to obtain the desired Conversion

Measurement	Base Unit	Factor	Conversion
Length	Millimeter (mm)	.03937	Inch. (In.)
Torque	Pound-Feet (Lb.Ft.)	1.355818	Newton-Meter (Nm)
	Newton-Meter (Nm)	.73756	Pound-Feet (Lb.Ft.)
	Ounce-Inch (Oz.In.)	.007062	Newton-Meter (Nm)
	Newton-Meter (Nm)	141.603	Ounce-Inch (Oz.In.)
Moment of Inertia	Pound-Feet Squared (Lb.Ft.^2	.042	Kilogram-Meter-Squared (Kgm^2)
	Kilogram-Meter-Squared (Kgm^2)	23.81	Pound-Feet Squared (Lb.Ft.^2
Energy	Foot-Pound (Ft.Lb.)	1.355818	Joule (J)
	Joule (J)	.73756	Foot-Pound (Ft.Lb.)
Force	Pound (Lb.)	4.448222	Newton (N)
	Newton (N)	.224808	Pound (Lb.)
Power	Horsepower (Hp)	.7457	Kilowatt (Kw)
	Kilowatt (Kw)	1.341	Horsepower (Hp)
Thermal Capacity	Horsepower-Seconds per Minute (Hp-Sec/Min)	12.42854	Watts (W)
	Watts (W)	.08046	Horsepower-Seconds per Minute (Hp-Sec/Min)
Temperature	Degrees Fahrenheit (F)	(F-32)*5/9	Degrees Celsius (C)
	Degrees Celsius (C)	(C*9/5)+32	Degrees Fahrenheit (F)