Siemens SINUMERIK 840D sl Operation/Programming Manual page 170

ShopTurn Functions
5
5.2 Drilling
5.2.2 Thread centered
1 cut
Stock removal
Chipbreaking
5-170
The "Thread centered" function is used to tap a right-hand or left-hand
thread in the center of the end face.
During machining, either the main spindle or counterspindle rotates.
You can alter the spindle speed via the spindle override; feedrate
override is not operative.
You can select drilling in one cut, chipbreaking or retraction from the
workpiece for stock removal.
The tool is moved at rapid traverse to the programmed position,
allowing for the retraction plane and safety clearance.
1. The tool drills at the programmed spindle speed S or cut rate V as
far as the final drilling depth Z1.
2. The direction of rotation of the spindle reverses and the tool
retracts to the safety clearance at the programmed spindle speed
SR or cut rate VR.
1. The tool drills at the programmed spindle speed S or feedrate V as
far as the first infeed depth (maximum infeed depth D).
2. The tool retracts from the workpiece to the safety clearance at
spindle speed SR or cut rate VR for stock removal.
3. Then the tool is inserted again as far as the 1st infeed depth at
spindle speed S or feedrate V and drills to the next infeed depth.
4. Steps 2 and 3 are repeated until the programmed final drilling
depth Z1 is reached.
5. The direction of rotation of the spindle reverses and the tool
retracts to the safety clearance at spindle speed SR or cut rate VR.
1. The tool drills at the programmed spindle speed S or feedrate V as
far as the first infeed depth (maximum infeed depth D).
2. The tool retracts by the retraction amount V2 for chipbreaking.
3. The tool then drills to the next infeed depth at spindle speed S or
feedrate V.
4. Steps 2 and 3 are repeated until the programmed final drilling
depth Z1 is reached.
5. The direction of rotation of the spindle reverses and the tool
retracts to the safety clearance at spindle speed SR or cut rate VR.
SINUMERIK 840D sl Operation/Programming ShopTurn (BAT) – 08/2005 Edition
08/2005
5
♥ Siemens AG, 2005. All rights reserved