The power, *P*, required for a machining operation is given by

Usually cutting speed is calculated using the original workpiece diameter.P= ( power / unit material removal rate )( material removal rate )

The specific or unit power isuwith units of [ power / ( volume / time ) ]

Material removal rate is

MRR = ( area of work material being removed )( rate at which this area is moving ) or

MRR = ( depth of cut )( feed distance per workpiece revolution )( cutting speed )

MRR =dfV

The depth of cut,MRR =d= ( initial diameter - final diameter ) / 2

In terms of spindle speed

Nand workpiece diameterD

Cutting speed isV= (Nrev/min )( Pi*D/ rev )

dfNPi*D

P=udfNPi*D

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© 2001 by Barney E. Klamecki. All rights reserved