HEIDENHAIN TNC 320 (340 55x-04) Cycle programming - Manual (Page 150)

150 Fixed Cycles: Pocket Milling / Stud Milling / Slot Milling
5.7 CIR
C
ULAR S
T
UD (Cy
c
le 257
, DIN/ISO: G257)
5.7 CIRCULAR STUD (Cycle 257,
DIN/ISO: G257)
Cycle run
Use Cycle 257 to machine a circular stud. If a diameter of the
workpiece blank is greater than the maximum possible stepover, then
the TNC performs multiple stepovers until the finished diameter has
been machined.
1 The tool moves from the cycle starting position (stud center) in the
positive X direction to the starting position for the stud machining.
The starting position is 2 mm to the right of the unmachined stud.
2 If the tool is at the 2nd setup clearance, it moves at rapid traverse
FMAX to the set-up clearance, and from there advances to the first
plunging depth at the feed rate for plunging.
3 The tool then moves tangentially on a semicircle to the stud
contour and machines one revolution.
4 If the finished diameter cannot be machined with one revolution,
the TNC performs a stepover with the current factor, and
machines another revolution. The TNC takes the dimensions of the
workpiece blank diameter, the finished diameter, and the
permitted stepover into account. This process is repeated until the
defined finished diameter has been reached.
5 The tool then tangentially departs the contour on a semicircle and
returns to the starting point for the stud machining.
6 The TNC then plunges the tool to the next plunging depth, and
machines the stud at this depth.
7 This process is repeated until the programmed stud depth is
reached.
X
Y
2mm