VARIOUS FUNCTIONS AND
PRECAUTIONS OF Symbolic FAPT
2. CAUTIONS FOR USING
2nd step: Calculation of the direction angles of major cutting edge and
minor cutting edge
There are certain items to be input by an operator according to
questions from the CRT screen. The following three factors are used
to determine the cutting edge direction angles.
CUTTING EDGE AC = (Cutting edge angle). . . . . . .
NOSE ANGLE AN = (Tool nose angle) . . . . . . . . .
SETTING ANGLE AS = (Setting angle). . . . . .
The following procedure shows the process of calculating the cutting
edge direction angles inside the system based on the above three pieces
(1)Assume AC be the major cutting edge angle and AN be the tool nose
(2)Calculate the minor cutting edge angle by AC’ = AC + AN.
(Example) AC’ = 30 + 45 = 75
(3)Convert setting angle AS according to the selected drawing format.
This is because that the system uses the value which is converted in
the first quadrant, irrespective of the specification of drawing format.
D If the selected drawing format is 1 or 2, AS is kept unchanged.
D If the selected drawing type is 3 or 4, AS is converted into –AS (AS
(4)Calculate the major cutting edge and minor cutting edge direction
A = AS – AC (major cutting edge)
A’ = AS – AC’ (minor cutting edge)