JamieR Frequent Poster
Joined: 30 Jun 2004 Posts: 54 Location: Chicago
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Posted: Fri Apr 29, 2005 5:35 pm Post subject: Haas--Constant Surface Speed |
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Q: I have a question about one of the programming examples in your operator’s manual. Here’s the example in question:
T200 B-2.0
G50 S2500
G97 S1042 M03
G00 G99 X2.0 Z0.01
T232 M08
G96 S600
G01 Z0 F.01
What is the purpose of the program line that has G97 S1042 M03 in it? I ask because of the G96 S600 code that follows two lines down in the program. This just doesn’t make sense to me.
A: When you invoke G96, Constant Surface Speed (CSS), the machine will automatically increase or decrease spindle speed according to the radius being cut (distance from tool tip to spindle centerline). This is an excellent way to ensure the proper cutting speed for the material being used. The common practice is to program with G97 (turn off CSS) when rpm adjustment is not necessary, such as during any rapid moves to approach the part or during drilling. A G96, with its increasing or decreasing speed, can sometimes be inconvenient during non-cutting moves. For example, if your programmed feed is in inches per rev and the tool tip moves outward, everything will slow down – and your cycle time will increase.
In conclusion: Use G96 only during cutting, and cancel it as soon as possible with a G97 command. |
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