Turning Against A Stop - Siemens SINUMERIK 808D User Manual

3.2.2

Turning against a stop

Example:
The following example explains the operating principle of limit stops using the axis direction keys.
You can also use the handwheel to perform the machining operation.
Task
The following shoulder with a finishing allowance of 0.2 mm must be turned:
● 100 mm in the Z direction
● 50 mm final diameter in the X direction
The end face starts at 0 mm in the Z direction. The blank diameter is 70 mm.
Operating sequences for infeeding to stop
1. Position the axes in front of the workpiece (for example, X +75 mm/Z +5 mm).
2. Check the machining technology data.
3. Set the following limit stops:
– -X at 50.4 mm
– -Z at -99.8 mm (due to finishing allowance)
– +Z at +5 mm
4. Delete the limit stop for +X; it is not required.
5. Start the spindle.
6. Using the handwheel, infeed to the 1st depth of cut in the X direction.
7. Start machining in the Z axis in the negative direction using the axis direction switch.
When the limit stop position in Z -99.8 mm is reached, the Z axis stops automatically.
A message is displayed, saying that limit stop -Z is reached.
8. Switch-out the axis direction switch.
9. Using the handwheel, retract the tool from the workpiece in the X direction.
10. Using the axis direction switch and rapid traverse override, move the tool in a positive Z direction towards the workpiece
until the axis stops.
A message is displayed, saying that limit stop +Z is reached.
11. Switch-out the axis direction switch.
12. Using the handwheel, infeed to the next depth of cut in the X direction.
13. Start machining in the Z axis in the negative direction using the axis direction switch.
Repeat the procedure until the depth of rough cut is reached.
A message is displayed as the tool is fed in, saying that limit stop -X is reached.
Once this cut has been completed, adjust the limit stops to the finished dimension, provided that the axes are positioned
in front of the workpiece.
Operating sequences for adjusting to finished dimension
1. Adjust the limit stops to the finished dimension: -X to 50.0 mm/-Z to -100.0 mm
2. Using the handwheel, infeed in the X direction until a message saying that limit stop -X is reached appears.
3. Start machining in the Z axis in the negative direction using the axis direction switch.
When the limit stop position in Z -100.0 mm is reached, the Z axis stops automatically.
A message is displayed, saying that limit stop -Z is reached.
4. Switch-out the axis direction switch in the Z direction and start in the positive X direction (finishing the end face).
5. Switch-out the axis direction switch in the X direction as soon as the tool tip leaves the workpiece.
Programming and Operating Manual (Manual Machine Plus (MM+), Turning)
01/2017
11