HEIDENHAIN TNC 640 (34059x-04) Cycle programming - Manual (Page 351)

RADIAL RECESSING EXTENDED
(Cycle 842, DIN/ISO: G842)
13.17
13
TNC 640 | User's Manual Cycle Programming | 3/2014
351
Finishing cycle run
The TNC uses the tool position as cycle starting point when a cycle
is called. If the Z coordinate of the starting point is less than
Q491
DIAMETER AT CONTOUR START, the TNC positions the tool in the X
coordinate to
Q491 and begins the cycle there.
1 The TNC positions the tool at rapid traverse to the first slot side.
2 The TNC finishes the side wall of the slot at the defined feed
rate Q505.
3 The TNC finishes the slot floor at the defined feed rate. If a
radius for contour edges Q500 was specified, the TNC finishes
the complete slot in one pass.
4 The TNC returns the tool at rapid traverse.
5 The TNC positions the tool at rapid traverse to the second slot
side.
6 The TNC finishes the side wall of the slot at the defined feed
rate
Q505.
7 The TNC positions the tool back at rapid traverse to the cycle
starting point.
Please note while programming:
Program a positioning block to the starting position
with radius compensation
R0 before the cycle call.
The tool position at cycle call defines the size of the
area to be machined (cycle starting point).
From the second infeed, the TNC reduces each
further cutting traverse by 0.1 mm. This reduces
lateral pressure on the tool. If the offset width
Q508
was input into the cycle, the TNC reduces the cutting
traverse by this value. After clearance roughing, the
remaining material is removed with a single cut. The
TNC generates an error message if the lateral offset
exceeds 80 % of the effective cutting width (effective
cutting width = cutting width –2*cutting radius).