Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set User Manual

Page 583

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Cylindrical Grinding Fixed Cycles

Chapter 17

17-9

Once reciprocating motion begins, it continues through program block
execution until a G80 is executed. If there is no G80, reciprocation
continues until an end of program (M02, M30, M99), or an emergency stop
condition occurs. An M99 in a subprogram simply returns program
execution to the main program and does not cancel reciprocation.

When reciprocation or a grinding cycle is canceled by a G80 or an M99,
the reciprocating axis continues to its secondary reversal point before the
control considers the G80 or M99 block completed.

This section describes the parameters that are common to all of the
cylindrical grinding cycles. See the section describing each specific cycle
for details on the parameters that directly control axis motion.

The system installer can define an axis as a diameter axis in AMP. Only
the plunge axis (X), pick axis (Z) and the reciprocation reversal points are
affected by diameter/radius programming (G07 or G08). Other parameters
are not affected by the controls diameter radius mode.

L -- number of spark-out passes or revolutions. The number entered
here (any integer from 0 to 999) indicates how many spark-out passes or
the number of spindle revolutions at which the wheel is to dwell for
spark-out after the final plunge depth has been reached. Spark-out refers to
repeating a final grinding pass or holding a final position without changing
plunge depth until there are practically no “sparks” (no material being
removed) from the part surface.

The L value refers to a number of reciprocation passes for G82 and G83.
It refers to a number of dither passes for G84 with an I value programmed,
and G85 with a K value programmed. It refers to a number of spindle
revolutions for G84 without an I value programmed, and G85 without a K
value programmed. It always refers to a number of spindle revolutions for
G86, G87, and G88. L can be number of spindle revolutions or number of
seconds to dwell during the G89 cycle.

This parameter is not “program modal.” If a value for the number of
spark-out passes is not programmed, then no spark-out passes are executed
for that cycle.

F -- plunge or plunge pick feedrate. The feedrate entered here is for the
plunge axis, whether it is making a continuous plunge towards the part, or
making incremental plunges. It must be within the range of legal F words
defined for your system. If no value is entered for this, then the last F
word executed in the part program is used as the plunge pick feedrate.

17.2
Cylindrical Grinding
Parameters

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