Cycle run, Please note while programming – HEIDENHAIN TNC 320 (340 55x-04) Cycle programming User Manual
Page 84

84
Fixed Cycles: Drilling
3.1
0
SINGLE-FLUTED DEEP
-HOLE DR
ILLING (Cy
c
le 241, DIN/ISO: G241)
3.10 SINGLE-FLUTED DEEP-HOLE
DRILLING (Cycle 241, DIN/ISO: 
G241)
Cycle run
1
The TNC positions the tool in the spindle axis to the entered setup 
clearance above the workpiece surface at rapid traverse FMAX.
2
Then the TNC moves the tool at the defined positioning feed rate 
to the setup clearance above the deepened starting point and 
switches on the drilling speed (M3) and the coolant. The TNC 
executes the approach motion at the direction of rotation defined 
in the cycle, with clockwise, counterclockwise or stationary 
spindle.
3
The tool drills to the entered drilling depth at the programmed feed 
rate F.
4
If programmed, the tool remains at the hole bottom for chip 
breaking. Then the TNC switches off the coolant and resets the 
drilling speed to the value defined for retraction.
5
After the dwell time at the hole bottom, the tool is retracted to the 
setup clearance at the retraction feed rate. If programmed, the tool 
moves to the 2nd setup clearance at FMAX.
Please note while programming:
Program a positioning block for the starting point (hole 
center) in the working plane with radius compensation R0.
The algebraic sign for the cycle parameter DEPTH 
determines the working direction. If you program DEPTH 
= 0, the cycle will not be executed. 
Danger of collision!
Use the machine parameter displayDepthErr to define 
whether, if a positive depth is entered, the TNC should 
output an error message (on) or not (off).
Keep in mind that the TNC reverses the calculation for pre-
positioning when a positive depth is entered. This 
means that the tool moves at rapid traverse in the tool axis 
to setup clearance below the workpiece surface!
