Siemens SINUMERIK 828D Function Manual page 1375

V1: Feedrates
17.2 Path feedrate F
At the end of the acceleration ramp, the position coupling between the spindle actual value (spindle setpoint with
SPCON on master spindle) and the axis setpoint is established. At this moment, the position of the axis in relation
to the zero mark of the spindle (including zero mark offsets) is as if the axis had accelerated abruptly at the start
of the block when the thread start position (zero mark plus SF) was crossed. Compensation is made for the
following error of the axis.
Minimum spindle speed
In order to ensure smooth rotation at low speeds, the spindle speed is not permitted to fall below a minimum
level.
This speed is defined using setting data:
SD43210 $SA_SPIND_MIN_VELO_G25 (minimum spindle speed)
and can be set for each gear step with the machine data:
MD35140 $MA_GEAR _STEP_MIN_VELO_LIMIT (minimum velocity for gear step change)
.
The minimum spindle speed can be changed in the part program with G25.
NC STOP, single block
NC STOP and single block (even at the block boundary) are only active after completion of thread chaining. All
subsequent G33 blocks and the first subsequent non­G33 block are traversed like a single block.
Premature abortion without destruction
Thread cutting can be aborted without destruction before the end point is reached. This can be done by activating
a retraction motion.
Thread cutting with ROT frame
With ROT frame and G33, G34, G35, alarm 10607 "Thread with frame not executable" is activated if the
rotation causes a change in the thread length and thus the lead. Rotation around the thread axis is permissible.
Alarm 10607 "Thread with frame not executable" can be suppressed by setting bit 12 in machine data:
MD11410 $MN_SUPPRESS_ALARM_MASK
, if the ROTstatement is used intentionally in the application.
All other frames are accepted by the NC without alarm. Attention is drawn to the lead­changing effect of SCALE.
Basic Functions
1375
Function Manual, 09/2011, 6FC5397-0BP40-2BA0