HEIDENHAIN TNC 426 (280 476) - Manual (Page 318)

HEIDENHAIN TNC 426, TNC 430 291
8.6 SL c
y
cles
REAMING (Cycle 21)
Process
Same as Cycle 1, Pecking; see “Cycles for Drilling, Tapping and Thread
Milling,” page 209.
Application
Cycle 21 is for PILOT DRILLING of the cutter infeed points. It accounts
for the allowance for side and the allowance for floor as well as the
radius of the rough-out tool. The cutter infeed points also serve as
starting points for roughing.
7 7 7 7 Plunging depth Q10 (incremental value): Dimension
by which the tool drills in each infeed (negative sign
for negative working direction)
7 7 7 7 Feed rate for plunging Q11: Traversing speed in
mm/min during drilling
7 7 7 7 Rough-out tool number Q13: Tool number of the
roughing mill
Example: NC blocks
58 CYCL DEF 21.0 PILOT DRILLING
Q10=+5 ;PLUNGING DEPTH
Q11=100 ;FEED RATE FOR PLUNGING
Q13=1 ;ROUGH-OUT TOOL
X
Y
When calculating the infeed points, the TNC does not
account for the delta value DR programmed in a TOOL
CALL block.
In narrow areas, the TNC may not be able to carry out pilot
drilling with a tool that is larger than the rough-out tool.