Siemens SINUMERIK 840D sl Programming Manual page 294

Measuring variants
3.6 Measure tool (milling)
● Maximum permissible feedrate when probing
● Minimum feedrate when probing
● Selecting the direction of rotation depending on the cutting edge geometry to avoid a hard
impact when probing at the probe
● Specified measuring accuracy
When performing a measurement with rotating tool, the ratio between the measuring feedrate
and speed must be taken into account. In this case, a cutting edge is considered. For multiple
cutting edges, the longest cutting edge is responsible for the measuring result.
The following interrelationships have to be taken into account:
n = S / (2π · r · 0.001)
F = n · Δ
Where:
n
S
r
F
Δ
Special issues when performing measurements with rotating spindle
● As standard, the feedrate and speed with the limit values defined in the general setting data
SD 54670 - SD 54677 for peripheral speed, speed, minimum feedrate maximum feedrate
and measuring accuracy, as well as the intended direction of spindle rotation for
measurement are calculated in a cycle (see Commissioning Manual
(IM9) / SINUMERIK 840D sl , Chapter "Tool measurement in milling - monitoring for
measuring with rotating spindle")
Measuring is conducted by probing twice; the 1st probing action causes a higher feedrate.
A maximum of three probing operations are possible for measuring. If probing is performed
several times the speed is additionally reduced on the last probing operation.
By setting the general SD 54740 $SNS_MEA_FUNCTION_MASK[Bit19], this speed
reduction can be suppressed.
● Using the general SD 54762 $SNS_MEA_FUNCTION_MASK_TOOL[Bit5], the user can
hide the cycle-internal calculation and enter the values for feedrate and speed via the input
screen form of the cycle.
To specify the values with bit 5 set in the general SD 54762
$SNS_MEA_FUNCTION_MASK_TOOL, the input fields in the screen form F1 (feedrate 1)
and S1 (speed 1), F2 (feedrate 2) and S2 (speed 2) or F3 (feed 3) and S3 (Speed 3) are
used. For the first probing, the values of F1 and S1 are effective, and for the second probing
the values F2 and S2. If S2=0, only one probing action is performed. If S3>0 and S2>0,
triple probing is performed, whereby for the 3rd probing, the values from F3 and S3 are
effective.
The monitoring functions for the general setting data SD 54670 - SD 54677 are not active!
● If, when calling the measuring cycle, the spindle is stationary, then the direction of rotation
is determined from the general SD 54674 $SNS_MEA_CM_SPIND_ROT_DIR.
294
Speed
Max. permissible peripheral speed
Tool radius
Measuring feedrate
Measuring accuracy
Basic system
Metric
rev/min
m/min
mm
mm/min
mm
SINUMERIK Operate
Programming Manual, 12/2017, 6FC5398-4BP40-6BA1
Inch
rev/min
Feet/min
Inch
inch/min
Inch
Measuring cycles