V1: Feedrates
17.4 Feedrate control
Basic Functions
1404
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
17.4.8
Feedrate for chamfer/rounding FRC, FRCM
General
The machining conditions can change significantly during surface transitions to chamfer/rounding. Hence, the
chamfer/rounding contour elements require dedicated, optimized feedrate values to achieve the desired surface
quality.
Function
You can program the feedrate for the chamfer/rounding with
FRC
(non-modal) or
FRCM
(modal).
The feedrate value is interpreted according to the type of feedrate active:
The
FRC
/
FRCM
value is applied depending upon the machine data:
MD20201 CHFRND_MODE_MASK
Reason: The feedrate type (
G94,G95,G96,G961
etc.) and thus the conversion to the internal format must be
consistent within the block for
F
and
FRC
/
FRCM
.
Empty blocks
When chamfer or rounding is active, the possible number of blocks containing no traversing information is limited.
The maximum number is defined in machine data:
MD20200 CHFRND_MAXNUM_DUMMY_BLOCKS.
The possible blocks without traversing information in the compensation plane are pure dummy commands and
are called empty blocks. For this reason, they may only be written between two blocks with traversing
information.
Boundary conditions
• Feedrate interpolation
FLIN
and
FCUB
is not possible for chamfer/rounding.
•
FRC
/
FRCM
has no effect if a chamfer is being machined with
G0
; the command can be programmed according
to the
F
value without error message.
•
FRC
is only effective if a chamfer/rounding is programmed in the same block or if
RNDM
has been activated.
•
FRC
overwrites the
F
or
FRCM
value for chamfer/rounding in the current block.
•
FRC
/
FRCM
must be set to a value greater than zero.
G94
,
G961
,
G971
:
Feedrate in mm/min, inch/min or
o
/min
G95
,
G96
,
G97
:
Revolutional feedrate in mm/rev or inch/rev
Bit 0 = 0
:
FRC
/
FRCM
from following block (default setting)
Bit 1 = 0
:
FRC
/
FRCM
from preceding block (recommended setting)
