Circular Stud (Cycle 257, Din/Iso: G257, Software Option 19); Cycle Run; Please Note While Programming - HEIDENHAIN TNC 620 User Manual

5.7 CIRCULAR STUD (Cycle 257, DIN/ISO:
G257, software option 19)

Cycle run

Use Cycle 257 to machine a circular stud. The TNC mills the circular
stud with a helical infeed motion starting from the workpiece blank
diameter.
1 If the tool is below the 2nd set-up clearance, the TNC retracts
the tool to the 2nd set-up clearance.
2 The tool moves from the stud center to the starting position for
stud machining. With the polar angle you specify the starting
position with respect to the stud center using parameter Q376.
3 The TNC moves the tool at rapid traverse FMAX to the set-up
clearance Q200, and from there advances to the first plunging
depth at the feed rate for plunging.
4 The TNC then machines the circular stud with a helical infeed
motion, taking the overlap factor into account.
5 The TNC retracts the tool from the contour by 2 mm on a
tangential path.
6 If more than one plunging movement is required, the tool
repeats the plunging movement at the point next to the
departure movement.
7 This process is repeated until the programmed stud depth is
reached.
8 At the end of the cycle, the tool departs on a tangential path and
then retracts in the tool axis to the 2nd set-up clearance defined
in the cycle.

Please note while programming:

Pre-position the tool in the machining plane to
the starting position (stud center) with radius
compensation R0.
The TNC automatically pre-positions the tool in the
tool axis. Note the 2nd set-up clearance Q204.
The algebraic sign for the cycle parameter DEPTH
determines the working direction. If you program
DEPTH=0, the cycle will not be executed.
At the end of the cycle, the TNC returns the tool to
the starting position.
The TNC reduces the infeed depth to the LCUTS tool
length defined in the tool table if the tool length is
shorter than the Q202 infeed depth programmed in
the cycle.
HEIDENHAIN | TNC 620 | User's manual for cycle programming | 9/2015
CIRCULAR STUD (Cycle 257, DIN/ISO: G257)
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