SPINDLE SPEED [N] : Spindle speed plays a very important role in calculating cutting speed. Spindle speed is also called RPM. This means how much revolution the spindle does in a minute is called RPM or spindle speed.
Suppose 2000 spindle speed. If you want to show spindle speed in a CNC program, it should be called S2000.
CUTTING SPEED: It is the speed at which material remove in one minute by cutting tool from a linear distance of workpiece. It is express as mm/min or m/min.
Cutting speed (Vc)= (π D1 N)/1000 mm/min
Where D1 = Uncut diameter of the workpiece
N = Spindle speed
Sometimes tool have cutting speed limitation . Consider limitation of tool for cutting speed Vc 200 to 250 and diameter D is 50. That time we need to calculate spindle speed
Let’s see the calculation ;
200 = (3.14 ×50×N)/1000
N = 1274 RPM
FEED: It is simply defined as a movement of cutting tool each cut . It is express as mm/rev.
DEPTH OF CUT : Thickness of metal removed in each cut of the tool . It is a perpendicular distance measure from the machined surface to the uncut surface of a workpiece .
Depth of cut calculation while performing turning
d = (D1-D2)/2