05-05-2012, 12:28 PM
Cutting Speed, Feed, and Depth of Cut
Cutting_Speed_Feed_and_DOC.ppt (Size: 484 KB / Downloads: 170)
Cutting Speed
Rate at which point on work circumference travels past cutting tool
Always expressed in feet per minute (ft/min) or meters per minute (m/min)
Important to use correct speed for material
Too high: cutting-tool breaks down rapidly
Too low: time lost, low production rates
Calculating Spindle Speed
Given in revolutions per minute
Cutting speed of metal and diameter of work must be known
Proper spindle speed set by dividing CS (in/min) by circumference of work (in)
Lathe Feed
Distance cutting tool advances along length of work for every revolution of the spindle
Feed of engine lathe dependent on speed of lead screw for feed rod
Speed controlled by change gears in quick-change gearbox
Bringing Diameter to Size Using Two Cuts
Roughing cut
Purpose to remove excess material quickly
Coarse feed: surface finish not too important
.010- to .015-in. (0.25- to 0.4-mm)
Finishing cut
Used to bring diameter to size
Fine feed: Produce good finish
.003- to .005-in (0.07- to 0.012-mm)