Material Removal Rate and Power - Solution Procedure

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

P = ( power / unit material removal rate )( material removal rate )
The specific or unit power is u with 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 = d f V

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

In terms of spindle speed N and workpiece diameter D
Cutting speed is V = ( N rev/min )( Pi*D / rev )

MRR = d f N Pi*D
P = u d f N Pi*D
Usually cutting speed is calculated using the original workpiece diameter.


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© 2001 by Barney E. Klamecki. All rights reserved