GSK 980MDc, User Manual

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GSK980MDc Milling CNC System User Manual
18
I Programming
Format: G95F_; (F0.0001~F500, leading zero can be omitted)
Command function: The cutting feedrate is offered by the unit of mm/rev., G95 is modal G command. The
G95 command can be omitted if the current mode is G95. When the CNC performs
G95 F_, the cutting feedrate is controlled by feedrate command based on
the multiplication of F command value (mm/rev) and current spindle speed
(rev/min). The actual feedrate varies with the spindle speed. The spindle cutting
feedrate per revolution is specified by G95 F_, the even cutting line can be formed on
the face of workpiece. It is necessary to install spindle encoder when the G95 mode is
operated.
The G94 and G95 are modal G commands at the same group, one of them is available only. The G94
is initial state G command, so, it defaults the G94 when the CNC is switched on. The following below shows
the conversion formula of feed value per rev. and feed value per min:
Fm = Fr×S
There into: Fm: feed value per minute (mm/min);
Fx: feed value per revolution (mm/r);
S: spindle speed (r/min).
The feedrate value is set by the CNC Data parameter
№ 026 when the CNC is
switched on, the F value is invariable after the F command is executed. The feedrate is 0 after F0 is
executed. The F value is invariable when CNC is reset or at emergent stop.
Note: In G95 mode, the cutting feedrate will be uneven when the spindle speed is less than 1 rev./min. The following
error will exist in the actual feedrate when the spindle speed vibration occurs.
To guarantee the machine quality, it is recommended that the spindle speed selected in machining is not
less than the lowest speed of available torque exported by spindle servo or inverter.
Cutting feed: The CNC makes tool movement path and the path (linear or circular arc) defined by
command into consistency (The circular interpolation can be performed by two
axis in selected plane when it is circular arc, the helical interpolation is formed by the
third axis linear interpolation linkage), by which, the CNC controls three directions
movement for X axis, Y axis, Z axis ,4th axis and 5th axis at the same time.
The instantaneous speed of movement path in a tangential direction is
consistent with the F command value, so this is called CUTTING FEED or
INTERPOLATION. The cutting feedrate is supplied by F command, which it is
disassembled to each interpolation axis according to the programming path
when the CNC performs the interpolation command (cutting feed).
Linear interpolation: The CNC can control the instantaneous speed in the directions of X axis, Y axis , Z
axis ,4th axis and 5th axis, so the vector resultant speed in these five directions are equal to
the F command value.
F
d d d d d
d
f
z y x
x
x
•
+ + + +
=
2
5
2
4
2 2 2
F
d d d d d
d
f
z y x
y
y
•
+ + + +
=
2
5
2
4
2 2 2