Thread Undercuts - Siemens SINUMERIK 840D sl Operation/Programming Manual

08/2005
5
Parameters
T, D, F, S, V See Sec. "Creating program blocks".
Position Position of undercut form E:
Position of undercut form F:
Undercut size Undercut size according to DIN table:
Radius/depth, e.g.: E1.0x0.4 (undercut form E) or
Reference point for dimensioning ¬ (abs)
X0
Z0 Reference point for dimensioning (abs)
Allowance in X direction ¬ (abs) or allowance in X direction (inc)
X1
Z1 Allowance in Z direction (abs or inc) – (for undercut form F only)
Cross-feed X ¬ (abs) or cross-feed X (inc)
V

5.3.4 Thread undercuts

Approach/retraction
♥ Siemens AG, 2005. All rights reserved
SINUMERIK 840D sl Operation/Programming ShopTurn (BAT) – 08/2005 Edition
Description
F0.6x0.3 (undercut form F)
The "Thread undercut DIN" or "Thread undercut" functions are used
when you want to program thread undercuts to DIN 76 for workpieces
with metric ISO threads or freely-definable thread undercuts.
1. The tool is moved at rapid traverse first to the return plane and
then to the safety clearance.
2. The first cut is made at machining feedrate starting from the flank
along the shape of the thread undercut as far as the safety
clearance.
3. The tool moves to the next starting position at rapid traverse.
4. Steps 2 and 3 are repeated until the thread undercut is finished.
5. The tool moves back to the return plane at rapid traverse.
During finishing the tool travels as far as cross-feed V.
Thread undercut
ShopTurn Functions
5
5.3 Turning
Unit
mm
mm
mm
mm
mm
5-201