I don't believe that is correct, the cutting speed would be dependent on the circumference of the part being turned.
Circumference is calculated as??¦°°ù2 (Pi times the radius squared).
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To calculate the actual cutting speed? at a specific RPM the formula would be:
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?¦°°ù2*RPM
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?For an object 3" in diameter at 1000 RPM the calculation would be:
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3" diameter divided by 2 = 1.5" radius
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1.5"*1.5"*¦°*1000 = 7068.6 Inches Per Minute
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If you want to calculate the RPM needed to meet a specific cutting speed the calculation would be:
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1/(¦°°ù2*/Cutting Speed) = RPM
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The RPM required for an object 3" in diameter with a cutting speed of 7068.6 inches per minute would be:
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1/(1.5"*1.5"*¦°/7068.6)? = 1000
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Cutting speed nomenclature is dependent on what linear measurement and rotational speed you use.
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If you do the calculation using the diameter/radius measured in inches you get inches out.
If you do the calculation using the diameter/radius measured in millimeters you millimeters out.
If you do the calculation using the diameter/radius measured in furlongs you get furlongs out.
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If you do the calculation using revolutions per minute you get distance per minute in out.
If you do the calculation using revolutions per second you get distance per second in? out.
If you do the calculation using revolutions per fortnight you get distance per fortnight in out.
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?Be aware; as the diameter is reduced the cutting speed is reduced, as you reduce the diameter of an object you may need to increase the RPM to maintain the desired cutting speed.
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Richard
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