Limiting wear offset amount

Submitted by Suhas L. More of Macro CNC Solutions

If an operator makes a mistake with an offset entry, the results can be disastrous. While it may not be possible to completely eliminate the potential for mistakes, you may be able to error-trap some pretty obvious error conditions. When making wear offset adjustments, for example, an operator should never need to have more than about plus or minus 0.3 inches in a wear offset (X or Z register). If they do, they’ve probably made an entry mistake – possibly typing 0.5 instead of 0.0005 – or 0.005, or even 0.05.

Error trapping this kind of mistake is easy with custom macro B. Consider this main program:

In the main program just before each turret index:

• .

• .

• .

• G65 P1000 T0101 U0.3 W0.3 (Test offset)

• T0101 (Turret index)

• .

• .

• .

Before every turret index, include a G65 command to call the testing macro the tool station number (we’ve duplicated the turret index word), the maximum wear offset X value (with U) and the maximum wear offset Z value (with W). With our example, if more than 0.3 or less than -0.3 is in an X or Z wear offset register, an alarm will be sounded.

Here is the custom macro that does the error-checking:

• O1000 (Custom macro)

• T#20

• #5=FIX[#20/100]

• #6=#20-[#5*100]

• #1=#[2000+#6]

• #2=#[2000+#6]

• IF[#1 GT #21] GOTO 99

• IF[#1 LT [0-#21]] GOTO 99

• IF[#2 GT #23] GOTO 999

• IF[#2 LT [0-#23]] GOTO 999

• GOTO 100

• N99

• #3000=101(X OFFSET OUT OF RANGE)

• N999

• #3000=102(Z OFFSET OUT OF RANGE)

• N100

• M99