LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
If the cutter bit does not cut satisfactorily, the speed
should be reduced.
Carbon steel tools, when used, require a reduction in
speed because they cannot withstand the heat produced as a result of high-
speed turning. Carbide-tipped tools, however, will stand speeds in excess
of those recommended for high-speed steel tools. The feed and depth of cut
should be average as described in paragraphs (c) and (d) below, for the
recommended speeds in table 2. If it desired to increase either the feed or
the depth of cut, the cutting speed should be proportionally reduced to
prevent overheating and excessive cutter bit wear.
(c) To determine the rotational speed necessary to produce a given
cutting speed, it is necessary to know the diameter of the workpiece to be
cut. To calculate the spindle speed, knowing the diameter of the workpiece,
use the following formula:
The formula above can be made into a simpler version by the process of
cancellation, where the constant of 3.1416 is divided into the constant of
12, thus eliminating one step when solving the problem using this formula.
The resulting formula would appear as: