GSK GSK928TE, Руководство пользователя

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GSK928TE
Ⅱ
Turning CNC System User Manual
89
the spindle encoder, and so the cutting points on the circle of machining workpiece are the same
when repeating the thread cutting many times, the spindle speed must not be changed at the
same time, otherwise there is the error of thread cutting.
The feedrate of thread cutting and the spindle speed are comfortable. If the spindle speed is high,
the system will not respond timely, which cause the thread to be damaged. The recommended
spindle speed is as follows: N × P
≤ 3000
N—spindle speed Unit
：
r/min Max. speed is less than 2000 r/min
P—thread lead Unit ： mm Inch thread value must be converted to the metric one.
There is wrong screw lead caused by the acceleration/deceleration when the thread cutting is
started and ended. To avoid the above-mentioned problem, the thread length defined is longer
than the actual requirement. Generally, the length is more than 1.3 mm when the thread is cut
with the acceleration.
Fig. 10 Thread cutting
Example
： thread lead: ２ mm, cutting depth: 2. ５ mm （ diameter value ， cutting twice ） as Fig. 10 ：
N0000 G00 X25 Z5
；
approach workpiece
N0010 G01 X23.5 F100
；
feed 1.5 mm (diameter programming)
N0020 G33 Z-50 P2 K2.5
；
the first thread cutting
N0030 G00 X26
；
tool retraction 2.
５
mm
N0040 Z5 ； return to the starting point
N0050 G01 X22.5
；
the second feeding 1mm
N0060 G33 Z-50 P2 K2.5
；
the second thread cutting
N0070 G00 X26 ； X tool retraction
N0080 Z5
；
z returns to starting point
Note 1:
The feed hold key and the feedrate override are invalid in the course of thread cutting.
Note 2:
In the course of thread cutting, the feed will stop once the spindle stops.
Note 3:
The photoelectric encoder with 1200 or 1024 lines must be installed to rotate with the
spindle synchronously. The selected encoder lines are the same as the actual installed
ones. When the encoder lines are 1200, P11 Bit 4 is 0; when the encoder lines are 1024,
P11 Bit 4 is 1. If the setting of Bit 4 is wrong, the pitch will be mistake when the thread is
machined.
Note 4:
For the thread with the thread run-out parameter in the command, the spindle speed, the
pitch, X acceleration time and X initial speed, I/K ratio in the program will affect the
length of thread run-out. The higher the speed is, the bigger the pitch is, the longer X
acceleration time is, the lower X initial speed is, the smaller I/K ratio is, the longer the
length of thread run-out is, vice versa, the shorter the length is. Relatively, I/K ratio has
more influence upon the length of thread run-out.
Note 5:
When the previous block and the current one are the thread cutting command, do not
detect the thread head signal (only one per rev) but directly start the cutting feed.